/*
- * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_OSREFERENCE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
- * This file contains Original Code and/or Modifications of Original Code
- * as defined in and that are subject to the Apple Public Source License
- * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. The rights granted to you under the
- * License may not be used to create, or enable the creation or
- * redistribution of, unlawful or unlicensed copies of an Apple operating
- * system, or to circumvent, violate, or enable the circumvention or
- * violation of, any terms of an Apple operating system software license
- * agreement.
- *
- * Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
- *
- * The Original Code and all software distributed under the License are
- * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
- * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
- * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
- * Please see the License for the specific language governing rights and
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
* limitations under the License.
- *
- * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* @OSF_FREE_COPYRIGHT@
*/
#include <debug.h>
-#include <mach_kdb.h>
-
-#include <ddb/db_output.h>
#include <mach/mach_types.h>
#include <mach/machine.h>
#include <mach/policy.h>
#include <mach/sync_policy.h>
+#include <mach/thread_act.h>
#include <machine/machine_routines.h>
#include <machine/sched_param.h>
+#include <machine/machine_cpu.h>
+#include <machine/machlimits.h>
+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+#include <machine/commpage.h>
+#endif
#include <kern/kern_types.h>
#include <kern/clock.h>
#include <kern/cpu_number.h>
#include <kern/cpu_data.h>
#include <kern/debug.h>
-#include <kern/lock.h>
#include <kern/macro_help.h>
#include <kern/machine.h>
#include <kern/misc_protos.h>
#include <kern/queue.h>
#include <kern/sched.h>
#include <kern/sched_prim.h>
+#include <kern/sfi.h>
#include <kern/syscall_subr.h>
#include <kern/task.h>
#include <kern/thread.h>
#include <kern/wait_queue.h>
+#include <kern/ledger.h>
+#include <kern/timer_queue.h>
#include <vm/pmap.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
+#include <mach/sdt.h>
+
#include <sys/kdebug.h>
-#ifdef __ppc__
-#include <ppc/pms.h>
+#include <kern/pms.h>
+
+#if defined(CONFIG_TELEMETRY) && defined(CONFIG_SCHED_TIMESHARE_CORE)
+#include <kern/telemetry.h>
#endif
+struct rt_queue rt_runq;
+#define RT_RUNQ ((processor_t)-1)
+decl_simple_lock_data(static,rt_lock);
+
+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+static struct fairshare_queue fs_runq;
+#define FS_RUNQ ((processor_t)-2)
+decl_simple_lock_data(static,fs_lock);
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+
#define DEFAULT_PREEMPTION_RATE 100 /* (1/s) */
int default_preemption_rate = DEFAULT_PREEMPTION_RATE;
+#define DEFAULT_BG_PREEMPTION_RATE 400 /* (1/s) */
+int default_bg_preemption_rate = DEFAULT_BG_PREEMPTION_RATE;
+
#define MAX_UNSAFE_QUANTA 800
int max_unsafe_quanta = MAX_UNSAFE_QUANTA;
#define SCHED_POLL_YIELD_SHIFT 4 /* 1/16 */
int sched_poll_yield_shift = SCHED_POLL_YIELD_SHIFT;
-uint64_t max_unsafe_computation;
-uint32_t sched_safe_duration;
uint64_t max_poll_computation;
+uint64_t max_unsafe_computation;
+uint64_t sched_safe_duration;
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
uint32_t std_quantum;
uint32_t min_std_quantum;
+uint32_t bg_quantum;
uint32_t std_quantum_us;
+uint32_t bg_quantum_us;
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+uint32_t thread_depress_time;
+uint32_t default_timeshare_computation;
+uint32_t default_timeshare_constraint;
uint32_t max_rt_quantum;
uint32_t min_rt_quantum;
-uint32_t sched_cswtime;
-
-static uint32_t delay_idle_limit, delay_idle_spin;
-static processor_t delay_idle(
- processor_t processor,
- thread_t self);
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
unsigned sched_tick;
uint32_t sched_tick_interval;
+#if defined(CONFIG_TELEMETRY)
+uint32_t sched_telemetry_interval;
+#endif /* CONFIG_TELEMETRY */
+
+uint32_t sched_pri_shift = INT8_MAX;
+uint32_t sched_background_pri_shift = INT8_MAX;
+uint32_t sched_combined_fgbg_pri_shift = INT8_MAX;
+uint32_t sched_fixed_shift;
+uint32_t sched_use_combined_fgbg_decay = 0;
+
+uint32_t sched_decay_usage_age_factor = 1; /* accelerate 5/8^n usage aging */
+
+/* Allow foreground to decay past default to resolve inversions */
+#define DEFAULT_DECAY_BAND_LIMIT ((BASEPRI_FOREGROUND - BASEPRI_DEFAULT) + 2)
+int sched_pri_decay_band_limit = DEFAULT_DECAY_BAND_LIMIT;
+
+/* Defaults for timer deadline profiling */
+#define TIMER_DEADLINE_TRACKING_BIN_1_DEFAULT 2000000 /* Timers with deadlines <=
+ * 2ms */
+#define TIMER_DEADLINE_TRACKING_BIN_2_DEFAULT 5000000 /* Timers with deadlines
+ <= 5ms */
+
+uint64_t timer_deadline_tracking_bin_1;
+uint64_t timer_deadline_tracking_bin_2;
+
+thread_t sched_maintenance_thread;
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static boolean_t sched_traditional_use_pset_runqueue = FALSE;
+
+__attribute__((always_inline))
+static inline run_queue_t runq_for_processor(processor_t processor)
+{
+ if (sched_traditional_use_pset_runqueue)
+ return &processor->processor_set->pset_runq;
+ else
+ return &processor->runq;
+}
-uint32_t sched_pri_shift;
+__attribute__((always_inline))
+static inline void runq_consider_incr_bound_count(processor_t processor, thread_t thread)
+{
+ if (thread->bound_processor == PROCESSOR_NULL)
+ return;
+
+ assert(thread->bound_processor == processor);
+
+ if (sched_traditional_use_pset_runqueue)
+ processor->processor_set->pset_runq_bound_count++;
+
+ processor->runq_bound_count++;
+}
+
+__attribute__((always_inline))
+static inline void runq_consider_decr_bound_count(processor_t processor, thread_t thread)
+{
+ if (thread->bound_processor == PROCESSOR_NULL)
+ return;
+
+ assert(thread->bound_processor == processor);
+
+ if (sched_traditional_use_pset_runqueue)
+ processor->processor_set->pset_runq_bound_count--;
+
+ processor->runq_bound_count--;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+uint64_t sched_one_second_interval;
+
+uint32_t sched_run_count, sched_share_count, sched_background_count;
+uint32_t sched_load_average, sched_mach_factor;
/* Forwards */
-void wait_queues_init(void);
-static void load_shift_init(void);
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+static void load_shift_init(void);
+static void preempt_pri_init(void);
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+static thread_t thread_select(
+ thread_t thread,
+ processor_t processor,
+ ast_t reason);
+
+#if CONFIG_SCHED_IDLE_IN_PLACE
+static thread_t thread_select_idle(
+ thread_t thread,
+ processor_t processor);
+#endif
+
+thread_t processor_idle(
+ thread_t thread,
+ processor_t processor);
+
+ast_t
+csw_check_locked( processor_t processor,
+ processor_set_t pset,
+ ast_t check_reason);
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static thread_t steal_thread(
+ processor_set_t pset);
-static thread_t choose_thread(
- processor_set_t pset,
+static thread_t steal_thread_disabled(
+ processor_set_t pset) __attribute__((unused));
+
+
+static thread_t steal_processor_thread(
processor_t processor);
static void thread_update_scan(void);
+static void processor_setrun(
+ processor_t processor,
+ thread_t thread,
+ integer_t options);
+
+static boolean_t
+processor_enqueue(
+ processor_t processor,
+ thread_t thread,
+ integer_t options);
+
+static boolean_t
+processor_queue_remove(
+ processor_t processor,
+ thread_t thread);
+
+static boolean_t processor_queue_empty(processor_t processor);
+
+static ast_t processor_csw_check(processor_t processor);
+
+static boolean_t processor_queue_has_priority(processor_t processor,
+ int priority,
+ boolean_t gte);
+
+static boolean_t should_current_thread_rechoose_processor(processor_t processor);
+
+static int sched_traditional_processor_runq_count(processor_t processor);
+
+static boolean_t sched_traditional_with_pset_runqueue_processor_queue_empty(processor_t processor);
+
+static uint64_t sched_traditional_processor_runq_stats_count_sum(processor_t processor);
+
+static uint64_t sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum(processor_t processor);
+
+static int sched_traditional_processor_bound_count(processor_t processor);
+
+#endif
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static void
+sched_traditional_processor_init(processor_t processor);
+
+static void
+sched_traditional_pset_init(processor_set_t pset);
+
+static void
+sched_traditional_with_pset_runqueue_init(void);
+
+#endif
+
+static void
+sched_realtime_init(void);
+
+static void
+sched_realtime_timebase_init(void);
+
+static void
+sched_timer_deadline_tracking_init(void);
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static sched_mode_t
+sched_traditional_initial_thread_sched_mode(task_t parent_task);
+
+static thread_t
+sched_traditional_choose_thread(
+ processor_t processor,
+ int priority,
+ __unused ast_t reason);
+
+#endif
+
#if DEBUG
-static
+extern int debug_task;
+#define TLOG(a, fmt, args...) if(debug_task & a) kprintf(fmt, ## args)
+#else
+#define TLOG(a, fmt, args...) do {} while (0)
+#endif
+
+__assert_only static
boolean_t thread_runnable(
thread_t thread);
-#endif /*DEBUG*/
-
-
/*
* State machine
*
*
*/
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+int8_t sched_load_shifts[NRQS];
+int sched_preempt_pri[NRQBM];
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+const struct sched_dispatch_table sched_traditional_dispatch = {
+ .init = sched_traditional_init,
+ .timebase_init = sched_traditional_timebase_init,
+ .processor_init = sched_traditional_processor_init,
+ .pset_init = sched_traditional_pset_init,
+ .maintenance_continuation = sched_traditional_maintenance_continue,
+ .choose_thread = sched_traditional_choose_thread,
+ .steal_thread = steal_thread,
+ .compute_priority = compute_priority,
+ .choose_processor = choose_processor,
+ .processor_enqueue = processor_enqueue,
+ .processor_queue_shutdown = processor_queue_shutdown,
+ .processor_queue_remove = processor_queue_remove,
+ .processor_queue_empty = processor_queue_empty,
+ .priority_is_urgent = priority_is_urgent,
+ .processor_csw_check = processor_csw_check,
+ .processor_queue_has_priority = processor_queue_has_priority,
+ .initial_quantum_size = sched_traditional_initial_quantum_size,
+ .initial_thread_sched_mode = sched_traditional_initial_thread_sched_mode,
+ .can_update_priority = can_update_priority,
+ .update_priority = update_priority,
+ .lightweight_update_priority = lightweight_update_priority,
+ .quantum_expire = sched_traditional_quantum_expire,
+ .should_current_thread_rechoose_processor = should_current_thread_rechoose_processor,
+ .processor_runq_count = sched_traditional_processor_runq_count,
+ .processor_runq_stats_count_sum = sched_traditional_processor_runq_stats_count_sum,
+ .fairshare_init = sched_traditional_fairshare_init,
+ .fairshare_runq_count = sched_traditional_fairshare_runq_count,
+ .fairshare_runq_stats_count_sum = sched_traditional_fairshare_runq_stats_count_sum,
+ .fairshare_enqueue = sched_traditional_fairshare_enqueue,
+ .fairshare_dequeue = sched_traditional_fairshare_dequeue,
+ .fairshare_queue_remove = sched_traditional_fairshare_queue_remove,
+ .processor_bound_count = sched_traditional_processor_bound_count,
+ .thread_update_scan = thread_update_scan,
+ .direct_dispatch_to_idle_processors = TRUE,
+};
+
+const struct sched_dispatch_table sched_traditional_with_pset_runqueue_dispatch = {
+ .init = sched_traditional_with_pset_runqueue_init,
+ .timebase_init = sched_traditional_timebase_init,
+ .processor_init = sched_traditional_processor_init,
+ .pset_init = sched_traditional_pset_init,
+ .maintenance_continuation = sched_traditional_maintenance_continue,
+ .choose_thread = sched_traditional_choose_thread,
+ .steal_thread = steal_thread,
+ .compute_priority = compute_priority,
+ .choose_processor = choose_processor,
+ .processor_enqueue = processor_enqueue,
+ .processor_queue_shutdown = processor_queue_shutdown,
+ .processor_queue_remove = processor_queue_remove,
+ .processor_queue_empty = sched_traditional_with_pset_runqueue_processor_queue_empty,
+ .priority_is_urgent = priority_is_urgent,
+ .processor_csw_check = processor_csw_check,
+ .processor_queue_has_priority = processor_queue_has_priority,
+ .initial_quantum_size = sched_traditional_initial_quantum_size,
+ .initial_thread_sched_mode = sched_traditional_initial_thread_sched_mode,
+ .can_update_priority = can_update_priority,
+ .update_priority = update_priority,
+ .lightweight_update_priority = lightweight_update_priority,
+ .quantum_expire = sched_traditional_quantum_expire,
+ .should_current_thread_rechoose_processor = should_current_thread_rechoose_processor,
+ .processor_runq_count = sched_traditional_processor_runq_count,
+ .processor_runq_stats_count_sum = sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum,
+ .fairshare_init = sched_traditional_fairshare_init,
+ .fairshare_runq_count = sched_traditional_fairshare_runq_count,
+ .fairshare_runq_stats_count_sum = sched_traditional_fairshare_runq_stats_count_sum,
+ .fairshare_enqueue = sched_traditional_fairshare_enqueue,
+ .fairshare_dequeue = sched_traditional_fairshare_dequeue,
+ .fairshare_queue_remove = sched_traditional_fairshare_queue_remove,
+ .processor_bound_count = sched_traditional_processor_bound_count,
+ .thread_update_scan = thread_update_scan,
+ .direct_dispatch_to_idle_processors = FALSE,
+};
+
+#endif
+
+const struct sched_dispatch_table *sched_current_dispatch = NULL;
+
/*
- * Waiting protocols and implementation:
- *
- * Each thread may be waiting for exactly one event; this event
- * is set using assert_wait(). That thread may be awakened either
- * by performing a thread_wakeup_prim() on its event,
- * or by directly waking that thread up with clear_wait().
- *
- * The implementation of wait events uses a hash table. Each
- * bucket is queue of threads having the same hash function
- * value; the chain for the queue (linked list) is the run queue
- * field. [It is not possible to be waiting and runnable at the
- * same time.]
- *
- * Locks on both the thread and on the hash buckets govern the
- * wait event field and the queue chain field. Because wakeup
- * operations only have the event as an argument, the event hash
- * bucket must be locked before any thread.
+ * Statically allocate a buffer to hold the longest possible
+ * scheduler description string, as currently implemented.
+ * bsd/kern/kern_sysctl.c has a corresponding definition in bsd/
+ * to export to userspace via sysctl(3). If either version
+ * changes, update the other.
*
- * Scheduling operations may also occur at interrupt level; therefore,
- * interrupts below splsched() must be prevented when holding
- * thread or hash bucket locks.
- *
- * The wait event hash table declarations are as follows:
+ * Note that in addition to being an upper bound on the strings
+ * in the kernel, it's also an exact parameter to PE_get_default(),
+ * which interrogates the device tree on some platforms. That
+ * API requires the caller know the exact size of the device tree
+ * property, so we need both a legacy size (32) and the current size
+ * (48) to deal with old and new device trees. The device tree property
+ * is similarly padded to a fixed size so that the same kernel image
+ * can run on multiple devices with different schedulers configured
+ * in the device tree.
*/
+#define SCHED_STRING_MAX_LENGTH (48)
-#define NUMQUEUES 59
+char sched_string[SCHED_STRING_MAX_LENGTH];
+static enum sched_enum _sched_enum __attribute__((used)) = sched_enum_unknown;
-struct wait_queue wait_queues[NUMQUEUES];
+/* Global flag which indicates whether Background Stepper Context is enabled */
+static int cpu_throttle_enabled = 1;
-#define wait_hash(event) \
- ((((int)(event) < 0)? ~(int)(event): (int)(event)) % NUMQUEUES)
+void
+sched_init(void)
+{
+ char sched_arg[SCHED_STRING_MAX_LENGTH] = { '\0' };
+
+ /* Check for runtime selection of the scheduler algorithm */
+ if (!PE_parse_boot_argn("sched", sched_arg, sizeof (sched_arg))) {
+ /* If no boot-args override, look in device tree */
+ if (!PE_get_default("kern.sched", sched_arg,
+ SCHED_STRING_MAX_LENGTH)) {
+ sched_arg[0] = '\0';
+ }
+ }
-int8_t sched_load_shifts[NRQS];
+
+ if (!PE_parse_boot_argn("sched_pri_decay_limit", &sched_pri_decay_band_limit, sizeof(sched_pri_decay_band_limit))) {
+ /* No boot-args, check in device tree */
+ if (!PE_get_default("kern.sched_pri_decay_limit",
+ &sched_pri_decay_band_limit,
+ sizeof(sched_pri_decay_band_limit))) {
+ /* Allow decay all the way to normal limits */
+ sched_pri_decay_band_limit = DEFAULT_DECAY_BAND_LIMIT;
+ }
+ }
+
+ kprintf("Setting scheduler priority decay band limit %d\n", sched_pri_decay_band_limit);
+
+ if (strlen(sched_arg) > 0) {
+ if (0) {
+ /* Allow pattern below */
+#if defined(CONFIG_SCHED_TRADITIONAL)
+ } else if (0 == strcmp(sched_arg, kSchedTraditionalString)) {
+ sched_current_dispatch = &sched_traditional_dispatch;
+ _sched_enum = sched_enum_traditional;
+ strlcpy(sched_string, kSchedTraditionalString, sizeof(sched_string));
+ } else if (0 == strcmp(sched_arg, kSchedTraditionalWithPsetRunqueueString)) {
+ sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+ _sched_enum = sched_enum_traditional_with_pset_runqueue;
+ strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_PROTO)
+ } else if (0 == strcmp(sched_arg, kSchedProtoString)) {
+ sched_current_dispatch = &sched_proto_dispatch;
+ _sched_enum = sched_enum_proto;
+ strlcpy(sched_string, kSchedProtoString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_GRRR)
+ } else if (0 == strcmp(sched_arg, kSchedGRRRString)) {
+ sched_current_dispatch = &sched_grrr_dispatch;
+ _sched_enum = sched_enum_grrr;
+ strlcpy(sched_string, kSchedGRRRString, sizeof(sched_string));
+#endif
+#if defined(CONFIG_SCHED_MULTIQ)
+ } else if (0 == strcmp(sched_arg, kSchedMultiQString)) {
+ sched_current_dispatch = &sched_multiq_dispatch;
+ _sched_enum = sched_enum_multiq;
+ strlcpy(sched_string, kSchedMultiQString, sizeof(sched_string));
+ } else if (0 == strcmp(sched_arg, kSchedDualQString)) {
+ sched_current_dispatch = &sched_dualq_dispatch;
+ _sched_enum = sched_enum_dualq;
+ strlcpy(sched_string, kSchedDualQString, sizeof(sched_string));
+#endif
+ } else {
+#if defined(CONFIG_SCHED_TRADITIONAL)
+ printf("Unrecognized scheduler algorithm: %s\n", sched_arg);
+ printf("Scheduler: Using instead: %s\n", kSchedTraditionalWithPsetRunqueueString);
+
+ sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+ _sched_enum = sched_enum_traditional_with_pset_runqueue;
+ strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#else
+ panic("Unrecognized scheduler algorithm: %s", sched_arg);
+#endif
+ }
+ kprintf("Scheduler: Runtime selection of %s\n", sched_string);
+ } else {
+#if defined(CONFIG_SCHED_MULTIQ)
+ sched_current_dispatch = &sched_multiq_dispatch;
+ _sched_enum = sched_enum_multiq;
+ strlcpy(sched_string, kSchedMultiQString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_TRADITIONAL)
+ sched_current_dispatch = &sched_traditional_with_pset_runqueue_dispatch;
+ _sched_enum = sched_enum_traditional_with_pset_runqueue;
+ strlcpy(sched_string, kSchedTraditionalWithPsetRunqueueString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_PROTO)
+ sched_current_dispatch = &sched_proto_dispatch;
+ _sched_enum = sched_enum_proto;
+ strlcpy(sched_string, kSchedProtoString, sizeof(sched_string));
+#elif defined(CONFIG_SCHED_GRRR)
+ sched_current_dispatch = &sched_grrr_dispatch;
+ _sched_enum = sched_enum_grrr;
+ strlcpy(sched_string, kSchedGRRRString, sizeof(sched_string));
+#else
+#error No default scheduler implementation
+#endif
+ kprintf("Scheduler: Default of %s\n", sched_string);
+ }
+
+ SCHED(init)();
+ SCHED(fairshare_init)();
+ sched_realtime_init();
+ ast_init();
+ sched_timer_deadline_tracking_init();
+
+ SCHED(pset_init)(&pset0);
+ SCHED(processor_init)(master_processor);
+}
void
-sched_init(void)
+sched_timebase_init(void)
+{
+ uint64_t abstime;
+
+ clock_interval_to_absolutetime_interval(1, NSEC_PER_SEC, &abstime);
+ sched_one_second_interval = abstime;
+
+ SCHED(timebase_init)();
+ sched_realtime_timebase_init();
+}
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+void
+sched_traditional_init(void)
{
/*
* Calculate the timeslicing quantum
printf("standard timeslicing quantum is %d us\n", std_quantum_us);
- sched_safe_duration = (2 * max_unsafe_quanta / default_preemption_rate) *
- (1 << SCHED_TICK_SHIFT);
+ if (default_bg_preemption_rate < 1)
+ default_bg_preemption_rate = DEFAULT_BG_PREEMPTION_RATE;
+ bg_quantum_us = (1000 * 1000) / default_bg_preemption_rate;
+
+ printf("standard background quantum is %d us\n", bg_quantum_us);
- wait_queues_init();
load_shift_init();
- pset_init(&default_pset);
+ preempt_pri_init();
sched_tick = 0;
- ast_init();
}
void
-sched_timebase_init(void)
+sched_traditional_timebase_init(void)
{
uint64_t abstime;
uint32_t shift;
clock_interval_to_absolutetime_interval(
std_quantum_us, NSEC_PER_USEC, &abstime);
assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- std_quantum = abstime;
+ std_quantum = (uint32_t)abstime;
/* smallest remaining quantum (250 us) */
clock_interval_to_absolutetime_interval(250, NSEC_PER_USEC, &abstime);
assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- min_std_quantum = abstime;
-
- /* smallest rt computaton (50 us) */
- clock_interval_to_absolutetime_interval(50, NSEC_PER_USEC, &abstime);
- assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- min_rt_quantum = abstime;
+ min_std_quantum = (uint32_t)abstime;
- /* maximum rt computation (50 ms) */
+ /* quantum for background tasks */
clock_interval_to_absolutetime_interval(
- 50, 1000*NSEC_PER_USEC, &abstime);
+ bg_quantum_us, NSEC_PER_USEC, &abstime);
assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- max_rt_quantum = abstime;
+ bg_quantum = (uint32_t)abstime;
/* scheduler tick interval */
clock_interval_to_absolutetime_interval(USEC_PER_SEC >> SCHED_TICK_SHIFT,
NSEC_PER_USEC, &abstime);
assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- sched_tick_interval = abstime;
+ sched_tick_interval = (uint32_t)abstime;
/*
* Compute conversion factor from usage to
abstime = (abstime * 5) / 3;
for (shift = 0; abstime > BASEPRI_DEFAULT; ++shift)
abstime >>= 1;
- sched_pri_shift = shift;
-
- max_unsafe_computation = max_unsafe_quanta * std_quantum;
- max_poll_computation = max_poll_quanta * std_quantum;
+ sched_fixed_shift = shift;
- /* delay idle constant(s) (60, 1 us) */
- clock_interval_to_absolutetime_interval(60, NSEC_PER_USEC, &abstime);
+ max_unsafe_computation = ((uint64_t)max_unsafe_quanta) * std_quantum;
+ sched_safe_duration = 2 * ((uint64_t)max_unsafe_quanta) * std_quantum;
+
+ max_poll_computation = ((uint64_t)max_poll_quanta) * std_quantum;
+ thread_depress_time = 1 * std_quantum;
+ default_timeshare_computation = std_quantum / 2;
+ default_timeshare_constraint = std_quantum;
+
+#if defined(CONFIG_TELEMETRY)
+ /* interval for high frequency telemetry */
+ clock_interval_to_absolutetime_interval(10, NSEC_PER_MSEC, &abstime);
assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- delay_idle_limit = abstime;
+ sched_telemetry_interval = (uint32_t)abstime;
+#endif
+}
- clock_interval_to_absolutetime_interval(1, NSEC_PER_USEC, &abstime);
- assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
- delay_idle_spin = abstime;
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static void
+sched_traditional_processor_init(processor_t processor)
+{
+ if (!sched_traditional_use_pset_runqueue) {
+ run_queue_init(&processor->runq);
+ }
+ processor->runq_bound_count = 0;
+}
+
+static void
+sched_traditional_pset_init(processor_set_t pset)
+{
+ if (sched_traditional_use_pset_runqueue) {
+ run_queue_init(&pset->pset_runq);
+ }
+ pset->pset_runq_bound_count = 0;
+}
+
+static void
+sched_traditional_with_pset_runqueue_init(void)
+{
+ sched_traditional_init();
+ sched_traditional_use_pset_runqueue = TRUE;
}
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
void
-wait_queues_init(void)
+sched_traditional_fairshare_init(void)
+{
+ simple_lock_init(&fs_lock, 0);
+
+ fs_runq.count = 0;
+ queue_init(&fs_runq.queue);
+}
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+
+static void
+sched_realtime_init(void)
{
- register int i;
+ simple_lock_init(&rt_lock, 0);
+
+ rt_runq.count = 0;
+ queue_init(&rt_runq.queue);
+}
+
+static void
+sched_realtime_timebase_init(void)
+{
+ uint64_t abstime;
+
+ /* smallest rt computaton (50 us) */
+ clock_interval_to_absolutetime_interval(50, NSEC_PER_USEC, &abstime);
+ assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
+ min_rt_quantum = (uint32_t)abstime;
+
+ /* maximum rt computation (50 ms) */
+ clock_interval_to_absolutetime_interval(
+ 50, 1000*NSEC_PER_USEC, &abstime);
+ assert((abstime >> 32) == 0 && (uint32_t)abstime != 0);
+ max_rt_quantum = (uint32_t)abstime;
- for (i = 0; i < NUMQUEUES; i++) {
- wait_queue_init(&wait_queues[i], SYNC_POLICY_FIFO);
- }
}
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
/*
* Set up values for timeshare
* loading factors.
int8_t k, *p = sched_load_shifts;
uint32_t i, j;
+ uint32_t sched_decay_penalty = 1;
+
+ if (PE_parse_boot_argn("sched_decay_penalty", &sched_decay_penalty, sizeof (sched_decay_penalty))) {
+ kprintf("Overriding scheduler decay penalty %u\n", sched_decay_penalty);
+ }
+
+ if (PE_parse_boot_argn("sched_decay_usage_age_factor", &sched_decay_usage_age_factor, sizeof (sched_decay_usage_age_factor))) {
+ kprintf("Overriding scheduler decay usage age factor %u\n", sched_decay_usage_age_factor);
+ }
+
+ if (PE_parse_boot_argn("sched_use_combined_fgbg_decay", &sched_use_combined_fgbg_decay, sizeof (sched_use_combined_fgbg_decay))) {
+ kprintf("Overriding schedule fg/bg decay calculation: %u\n", sched_use_combined_fgbg_decay);
+ }
+
+ if (sched_decay_penalty == 0) {
+ /*
+ * There is no penalty for timeshare threads for using too much
+ * CPU, so set all load shifts to INT8_MIN. Even under high load,
+ * sched_pri_shift will be >INT8_MAX, and there will be no
+ * penalty applied to threads (nor will sched_usage be updated per
+ * thread).
+ */
+ for (i = 0; i < NRQS; i++) {
+ sched_load_shifts[i] = INT8_MIN;
+ }
+
+ return;
+ }
+
*p++ = INT8_MIN; *p++ = 0;
- for (i = j = 2, k = 1; i < NRQS; ++k) {
- for (j <<= 1; i < j; ++i)
+ /*
+ * For a given system load "i", the per-thread priority
+ * penalty per quantum of CPU usage is ~2^k priority
+ * levels. "sched_decay_penalty" can cause more
+ * array entries to be filled with smaller "k" values
+ */
+ for (i = 2, j = 1 << sched_decay_penalty, k = 1; i < NRQS; ++k) {
+ for (j <<= 1; (i < j) && (i < NRQS); ++i)
*p++ = k;
}
}
+static void
+preempt_pri_init(void)
+{
+ int i, *p = sched_preempt_pri;
+
+ for (i = BASEPRI_FOREGROUND; i < MINPRI_KERNEL; ++i)
+ setbit(i, p);
+
+ for (i = BASEPRI_PREEMPT; i <= MAXPRI; ++i)
+ setbit(i, p);
+}
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
/*
* Thread wait timer expiration.
*/
splx(s);
}
-/*
- * thread_set_timer:
- *
- * Set a timer for the current thread, if the thread
- * is ready to wait. Must be called between assert_wait()
- * and thread_block().
- */
-void
-thread_set_timer(
- uint32_t interval,
- uint32_t scale_factor)
-{
- thread_t thread = current_thread();
- uint64_t deadline;
- spl_t s;
-
- s = splsched();
- thread_lock(thread);
- if ((thread->state & TH_WAIT) != 0) {
- clock_interval_to_deadline(interval, scale_factor, &deadline);
- if (!timer_call_enter(&thread->wait_timer, deadline))
- thread->wait_timer_active++;
- thread->wait_timer_is_set = TRUE;
- }
- thread_unlock(thread);
- splx(s);
-}
-
-void
-thread_set_timer_deadline(
- uint64_t deadline)
-{
- thread_t thread = current_thread();
- spl_t s;
-
- s = splsched();
- thread_lock(thread);
- if ((thread->state & TH_WAIT) != 0) {
- if (!timer_call_enter(&thread->wait_timer, deadline))
- thread->wait_timer_active++;
- thread->wait_timer_is_set = TRUE;
- }
- thread_unlock(thread);
- splx(s);
-}
-
-void
-thread_cancel_timer(void)
-{
- thread_t thread = current_thread();
- spl_t s;
-
- s = splsched();
- thread_lock(thread);
- if (thread->wait_timer_is_set) {
- if (timer_call_cancel(&thread->wait_timer))
- thread->wait_timer_active--;
- thread->wait_timer_is_set = FALSE;
- }
- thread_unlock(thread);
- splx(s);
-}
-
/*
* thread_unblock:
*
wait_result_t wresult)
{
boolean_t result = FALSE;
+ thread_t cthread = current_thread();
+ uint32_t new_run_count;
/*
- * Set wait_result.
+ * Set wait_result.
*/
thread->wait_result = wresult;
/*
- * Cancel pending wait timer.
+ * Cancel pending wait timer.
*/
if (thread->wait_timer_is_set) {
if (timer_call_cancel(&thread->wait_timer))
}
/*
- * Update scheduling state.
+ * Update scheduling state: not waiting,
+ * set running.
*/
thread->state &= ~(TH_WAIT|TH_UNINT);
if (!(thread->state & TH_RUN)) {
thread->state |= TH_RUN;
+ (*thread->sched_call)(SCHED_CALL_UNBLOCK, thread);
+
/*
- * Mark unblocked if call out.
+ * Update run counts.
*/
- if (thread->options & TH_OPT_CALLOUT)
- call_thread_unblock();
+ new_run_count = sched_run_incr(thread);
+ if (thread->sched_mode == TH_MODE_TIMESHARE) {
+ sched_share_incr(thread);
+ if (thread->sched_flags & TH_SFLAG_THROTTLED)
+ sched_background_incr(thread);
+ }
+ }
+ else {
/*
- * Update pset run counts.
+ * Signal if idling on another processor.
*/
- pset_run_incr(thread->processor_set);
- if (thread->sched_mode & TH_MODE_TIMESHARE)
- pset_share_incr(thread->processor_set);
- }
- else
- result = TRUE;
+#if CONFIG_SCHED_IDLE_IN_PLACE
+ if (thread->state & TH_IDLE) {
+ processor_t processor = thread->last_processor;
- /*
+ if (processor != current_processor())
+ machine_signal_idle(processor);
+ }
+#else
+ assert((thread->state & TH_IDLE) == 0);
+#endif
+
+ new_run_count = sched_run_count; /* updated in thread_select_idle() */
+ result = TRUE;
+ }
+
+ /*
* Calculate deadline for real-time threads.
*/
- if (thread->sched_mode & TH_MODE_REALTIME) {
- thread->realtime.deadline = mach_absolute_time();
- thread->realtime.deadline += thread->realtime.constraint;
+ if (thread->sched_mode == TH_MODE_REALTIME) {
+ uint64_t ctime;
+
+ ctime = mach_absolute_time();
+ thread->realtime.deadline = thread->realtime.constraint + ctime;
}
/*
* Clear old quantum, fail-safe computation, etc.
*/
- thread->current_quantum = 0;
+ thread->quantum_remaining = 0;
thread->computation_metered = 0;
thread->reason = AST_NONE;
- KERNEL_DEBUG_CONSTANT(
+ /* Obtain power-relevant interrupt and "platform-idle exit" statistics.
+ * We also account for "double hop" thread signaling via
+ * the thread callout infrastructure.
+ * DRK: consider removing the callout wakeup counters in the future
+ * they're present for verification at the moment.
+ */
+ boolean_t aticontext, pidle;
+ ml_get_power_state(&aticontext, &pidle);
+
+ if (__improbable(aticontext && !(thread_get_tag_internal(thread) & THREAD_TAG_CALLOUT))) {
+ ledger_credit(thread->t_ledger, task_ledgers.interrupt_wakeups, 1);
+ DTRACE_SCHED2(iwakeup, struct thread *, thread, struct proc *, thread->task->bsd_info);
+
+ uint64_t ttd = PROCESSOR_DATA(current_processor(), timer_call_ttd);
+
+ if (ttd) {
+ if (ttd <= timer_deadline_tracking_bin_1)
+ thread->thread_timer_wakeups_bin_1++;
+ else
+ if (ttd <= timer_deadline_tracking_bin_2)
+ thread->thread_timer_wakeups_bin_2++;
+ }
+
+ if (pidle) {
+ ledger_credit(thread->t_ledger, task_ledgers.platform_idle_wakeups, 1);
+ }
+
+ } else if (thread_get_tag_internal(cthread) & THREAD_TAG_CALLOUT) {
+ if (cthread->callout_woken_from_icontext) {
+ ledger_credit(thread->t_ledger, task_ledgers.interrupt_wakeups, 1);
+ thread->thread_callout_interrupt_wakeups++;
+ if (cthread->callout_woken_from_platform_idle) {
+ ledger_credit(thread->t_ledger, task_ledgers.platform_idle_wakeups, 1);
+ thread->thread_callout_platform_idle_wakeups++;
+ }
+
+ cthread->callout_woke_thread = TRUE;
+ }
+ }
+
+ if (thread_get_tag_internal(thread) & THREAD_TAG_CALLOUT) {
+ thread->callout_woken_from_icontext = aticontext;
+ thread->callout_woken_from_platform_idle = pidle;
+ thread->callout_woke_thread = FALSE;
+ }
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
MACHDBG_CODE(DBG_MACH_SCHED,MACH_MAKE_RUNNABLE) | DBG_FUNC_NONE,
- (int)thread, (int)thread->sched_pri, 0, 0, 0);
+ (uintptr_t)thread_tid(thread), thread->sched_pri, thread->wait_result, new_run_count, 0);
+
+ DTRACE_SCHED2(wakeup, struct thread *, thread, struct proc *, thread->task->bsd_info);
return (result);
}
{
boolean_t at_safe_point;
+ assert(thread == current_thread());
+
/*
* The thread may have certain types of interrupts/aborts masked
* off. Even if the wait location says these types of interrupts
at_safe_point = (interruptible == THREAD_ABORTSAFE);
if ( interruptible == THREAD_UNINT ||
- !(thread->state & TH_ABORT) ||
+ !(thread->sched_flags & TH_SFLAG_ABORT) ||
(!at_safe_point &&
- (thread->state & TH_ABORT_SAFELY)) ) {
+ (thread->sched_flags & TH_SFLAG_ABORTSAFELY))) {
+
+ if ( !(thread->state & TH_TERMINATE))
+ DTRACE_SCHED(sleep);
+
thread->state |= (interruptible) ? TH_WAIT : (TH_WAIT | TH_UNINT);
thread->at_safe_point = at_safe_point;
return (thread->wait_result = THREAD_WAITING);
}
else
- if (thread->state & TH_ABORT_SAFELY)
- thread->state &= ~(TH_ABORT|TH_ABORT_SAFELY);
+ if (thread->sched_flags & TH_SFLAG_ABORTSAFELY)
+ thread->sched_flags &= ~TH_SFLAG_ABORTED_MASK;
return (thread->wait_result = THREAD_INTERRUPTED);
}
register wait_queue_t wq;
register int index;
- assert(event != NO_EVENT);
+ if(event == NO_EVENT)
+ panic("assert_wait() called with NO_EVENT");
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+ VM_KERNEL_UNSLIDE(event), 0, 0, 0, 0);
index = wait_hash(event);
wq = &wait_queues[index];
uint64_t deadline;
spl_t s;
- assert(event != NO_EVENT);
+ if(event == NO_EVENT)
+ panic("assert_wait_timeout() called with NO_EVENT");
+
wqueue = &wait_queues[wait_hash(event)];
s = splsched();
thread_lock(thread);
clock_interval_to_deadline(interval, scale_factor, &deadline);
- wresult = wait_queue_assert_wait64_locked(wqueue, (uint32_t)event,
- interruptible, deadline, thread);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+ VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+
+ wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t, event),
+ interruptible,
+ TIMEOUT_URGENCY_SYS_NORMAL,
+ deadline, 0,
+ thread);
thread_unlock(thread);
wait_queue_unlock(wqueue);
}
wait_result_t
-assert_wait_deadline(
+assert_wait_timeout_with_leeway(
event_t event,
wait_interrupt_t interruptible,
- uint64_t deadline)
+ wait_timeout_urgency_t urgency,
+ uint32_t interval,
+ uint32_t leeway,
+ uint32_t scale_factor)
{
thread_t thread = current_thread();
wait_result_t wresult;
wait_queue_t wqueue;
+ uint64_t deadline;
+ uint64_t abstime;
+ uint64_t slop;
+ uint64_t now;
spl_t s;
- assert(event != NO_EVENT);
+ now = mach_absolute_time();
+ clock_interval_to_absolutetime_interval(interval, scale_factor, &abstime);
+ deadline = now + abstime;
+
+ clock_interval_to_absolutetime_interval(leeway, scale_factor, &slop);
+
+ if(event == NO_EVENT)
+ panic("assert_wait_timeout_with_leeway() called with NO_EVENT");
+
wqueue = &wait_queues[wait_hash(event)];
s = splsched();
wait_queue_lock(wqueue);
thread_lock(thread);
- wresult = wait_queue_assert_wait64_locked(wqueue, (uint32_t)event,
- interruptible, deadline, thread);
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+ VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+
+ wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t, event),
+ interruptible,
+ urgency, deadline, slop,
+ thread);
thread_unlock(thread);
wait_queue_unlock(wqueue);
return (wresult);
}
-/*
- * thread_sleep_fast_usimple_lock:
- *
- * Cause the current thread to wait until the specified event
- * occurs. The specified simple_lock is unlocked before releasing
- * the cpu and re-acquired as part of waking up.
- *
- * This is the simple lock sleep interface for components that use a
- * faster version of simple_lock() than is provided by usimple_lock().
- */
-__private_extern__ wait_result_t
-thread_sleep_fast_usimple_lock(
- event_t event,
- simple_lock_t lock,
- wait_interrupt_t interruptible)
+wait_result_t
+assert_wait_deadline(
+ event_t event,
+ wait_interrupt_t interruptible,
+ uint64_t deadline)
{
- wait_result_t res;
+ thread_t thread = current_thread();
+ wait_result_t wresult;
+ wait_queue_t wqueue;
+ spl_t s;
- res = assert_wait(event, interruptible);
- if (res == THREAD_WAITING) {
- simple_unlock(lock);
- res = thread_block(THREAD_CONTINUE_NULL);
- simple_lock(lock);
- }
- return res;
-}
+ assert(event != NO_EVENT);
+ wqueue = &wait_queues[wait_hash(event)];
+
+ s = splsched();
+ wait_queue_lock(wqueue);
+ thread_lock(thread);
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+ VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
-/*
- * thread_sleep_usimple_lock:
- *
- * Cause the current thread to wait until the specified event
- * occurs. The specified usimple_lock is unlocked before releasing
- * the cpu and re-acquired as part of waking up.
- *
- * This is the simple lock sleep interface for components where
- * simple_lock() is defined in terms of usimple_lock().
- */
-wait_result_t
-thread_sleep_usimple_lock(
- event_t event,
- usimple_lock_t lock,
- wait_interrupt_t interruptible)
-{
- wait_result_t res;
+ wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t,event),
+ interruptible,
+ TIMEOUT_URGENCY_SYS_NORMAL, deadline, 0,
+ thread);
- res = assert_wait(event, interruptible);
- if (res == THREAD_WAITING) {
- usimple_unlock(lock);
- res = thread_block(THREAD_CONTINUE_NULL);
- usimple_lock(lock);
- }
- return res;
+ thread_unlock(thread);
+ wait_queue_unlock(wqueue);
+ splx(s);
+
+ return (wresult);
}
-/*
- * thread_sleep_mutex:
- *
- * Cause the current thread to wait until the specified event
- * occurs. The specified mutex is unlocked before releasing
- * the cpu. The mutex will be re-acquired before returning.
- *
- * JMM - Add hint to make sure mutex is available before rousting
- */
wait_result_t
-thread_sleep_mutex(
- event_t event,
- mutex_t *mutex,
- wait_interrupt_t interruptible)
+assert_wait_deadline_with_leeway(
+ event_t event,
+ wait_interrupt_t interruptible,
+ wait_timeout_urgency_t urgency,
+ uint64_t deadline,
+ uint64_t leeway)
{
- wait_result_t res;
+ thread_t thread = current_thread();
+ wait_result_t wresult;
+ wait_queue_t wqueue;
+ spl_t s;
- res = assert_wait(event, interruptible);
- if (res == THREAD_WAITING) {
- mutex_unlock(mutex);
- res = thread_block(THREAD_CONTINUE_NULL);
- mutex_lock(mutex);
- }
- return res;
-}
-
-/*
- * thread_sleep_mutex_deadline:
- *
- * Cause the current thread to wait until the specified event
- * (or deadline) occurs. The specified mutex is unlocked before
- * releasing the cpu. The mutex will be re-acquired before returning.
- */
-wait_result_t
-thread_sleep_mutex_deadline(
- event_t event,
- mutex_t *mutex,
- uint64_t deadline,
- wait_interrupt_t interruptible)
-{
- wait_result_t res;
+ if(event == NO_EVENT)
+ panic("assert_wait_deadline_with_leeway() called with NO_EVENT");
- res = assert_wait_deadline(event, interruptible, deadline);
- if (res == THREAD_WAITING) {
- mutex_unlock(mutex);
- res = thread_block(THREAD_CONTINUE_NULL);
- mutex_lock(mutex);
- }
- return res;
+ wqueue = &wait_queues[wait_hash(event)];
+
+ s = splsched();
+ wait_queue_lock(wqueue);
+ thread_lock(thread);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_WAIT)|DBG_FUNC_NONE,
+ VM_KERNEL_UNSLIDE(event), interruptible, deadline, 0, 0);
+
+ wresult = wait_queue_assert_wait64_locked(wqueue, CAST_DOWN(event64_t,event),
+ interruptible,
+ urgency, deadline, leeway,
+ thread);
+
+ thread_unlock(thread);
+ wait_queue_unlock(wqueue);
+ splx(s);
+
+ return (wresult);
}
/*
- * thread_sleep_lock_write:
+ * thread_isoncpu:
*
- * Cause the current thread to wait until the specified event
- * occurs. The specified (write) lock is unlocked before releasing
- * the cpu. The (write) lock will be re-acquired before returning.
+ * Return TRUE if a thread is running on a processor such that an AST
+ * is needed to pull it out of userspace execution, or if executing in
+ * the kernel, bring to a context switch boundary that would cause
+ * thread state to be serialized in the thread PCB.
+ *
+ * Thread locked, returns the same way. While locked, fields
+ * like "state" cannot change. "runq" can change only from set to unset.
*/
-wait_result_t
-thread_sleep_lock_write(
- event_t event,
- lock_t *lock,
- wait_interrupt_t interruptible)
+static inline boolean_t
+thread_isoncpu(thread_t thread)
{
- wait_result_t res;
+ /* Not running or runnable */
+ if (!(thread->state & TH_RUN))
+ return (FALSE);
- res = assert_wait(event, interruptible);
- if (res == THREAD_WAITING) {
- lock_write_done(lock);
- res = thread_block(THREAD_CONTINUE_NULL);
- lock_write(lock);
- }
- return res;
+ /* Waiting on a runqueue, not currently running */
+ /* TODO: This is invalid - it can get dequeued without thread lock, but not context switched. */
+ if (thread->runq != PROCESSOR_NULL)
+ return (FALSE);
+
+ /*
+ * Thread must be running on a processor, or
+ * about to run, or just did run. In all these
+ * cases, an AST to the processor is needed
+ * to guarantee that the thread is kicked out
+ * of userspace and the processor has
+ * context switched (and saved register state).
+ */
+ return (TRUE);
}
/*
* thread_stop:
*
* Force a preemption point for a thread and wait
- * for it to stop running. Arbitrates access among
+ * for it to stop running on a CPU. If a stronger
+ * guarantee is requested, wait until no longer
+ * runnable. Arbitrates access among
* multiple stop requests. (released by unstop)
*
* The thread must enter a wait state and stop via a
*/
boolean_t
thread_stop(
- thread_t thread)
+ thread_t thread,
+ boolean_t until_not_runnable)
{
wait_result_t wresult;
- spl_t s;
+ spl_t s = splsched();
+ boolean_t oncpu;
- s = splsched();
wake_lock(thread);
+ thread_lock(thread);
while (thread->state & TH_SUSP) {
thread->wake_active = TRUE;
+ thread_unlock(thread);
+
wresult = assert_wait(&thread->wake_active, THREAD_ABORTSAFE);
wake_unlock(thread);
splx(s);
s = splsched();
wake_lock(thread);
+ thread_lock(thread);
}
- thread_lock(thread);
thread->state |= TH_SUSP;
- while (thread->state & TH_RUN) {
- processor_t processor = thread->last_processor;
-
- if ( processor != PROCESSOR_NULL &&
- processor->state == PROCESSOR_RUNNING &&
- processor->active_thread == thread )
+ while ((oncpu = thread_isoncpu(thread)) ||
+ (until_not_runnable && (thread->state & TH_RUN))) {
+ processor_t processor;
+
+ if (oncpu) {
+ assert(thread->state & TH_RUN);
+ processor = thread->chosen_processor;
cause_ast_check(processor);
- thread_unlock(thread);
+ }
thread->wake_active = TRUE;
+ thread_unlock(thread);
+
wresult = assert_wait(&thread->wake_active, THREAD_ABORTSAFE);
wake_unlock(thread);
splx(s);
thread_unlock(thread);
wake_unlock(thread);
splx(s);
+
+ /*
+ * We return with the thread unlocked. To prevent it from
+ * transitioning to a runnable state (or from TH_RUN to
+ * being on the CPU), the caller must ensure the thread
+ * is stopped via an external means (such as an AST)
+ */
return (TRUE);
}
if (thread->wake_active) {
thread->wake_active = FALSE;
thread_unlock(thread);
+
+ thread_wakeup(&thread->wake_active);
wake_unlock(thread);
splx(s);
- thread_wakeup(&thread->wake_active);
return;
}
}
*/
void
thread_wait(
- thread_t thread)
+ thread_t thread,
+ boolean_t until_not_runnable)
{
wait_result_t wresult;
- spl_t s = splsched();
+ boolean_t oncpu;
+ processor_t processor;
+ spl_t s = splsched();
wake_lock(thread);
thread_lock(thread);
- while (thread->state & TH_RUN) {
- processor_t processor = thread->last_processor;
+ /*
+ * Wait until not running on a CPU. If stronger requirement
+ * desired, wait until not runnable. Assumption: if thread is
+ * on CPU, then TH_RUN is set, so we're not waiting in any case
+ * where the original, pure "TH_RUN" check would have let us
+ * finish.
+ */
+ while ((oncpu = thread_isoncpu(thread)) ||
+ (until_not_runnable && (thread->state & TH_RUN))) {
- if ( processor != PROCESSOR_NULL &&
- processor->state == PROCESSOR_RUNNING &&
- processor->active_thread == thread )
+ if (oncpu) {
+ assert(thread->state & TH_RUN);
+ processor = thread->chosen_processor;
cause_ast_check(processor);
- thread_unlock(thread);
+ }
thread->wake_active = TRUE;
+ thread_unlock(thread);
+
wresult = assert_wait(&thread->wake_active, THREAD_UNINT);
wake_unlock(thread);
splx(s);
wait_result_t wresult)
{
wait_queue_t wq = thread->wait_queue;
- int i = LockTimeOut;
+ uint32_t i = LockTimeOut;
do {
if (wresult == THREAD_INTERRUPTED && (thread->state & TH_UNINT))
}
return (thread_go(thread, wresult));
- } while (--i > 0);
+ } while ((--i > 0) || machine_timeout_suspended());
- panic("clear_wait_internal: deadlock: thread=0x%x, wq=0x%x, cpu=%d\n",
+ panic("clear_wait_internal: deadlock: thread=%p, wq=%p, cpu=%d\n",
thread, wq, cpu_number());
return (KERN_FAILURE);
thread_wakeup_prim(
event_t event,
boolean_t one_thread,
- wait_result_t result)
+ wait_result_t result)
+{
+ return (thread_wakeup_prim_internal(event, one_thread, result, -1));
+}
+
+
+kern_return_t
+thread_wakeup_prim_internal(
+ event_t event,
+ boolean_t one_thread,
+ wait_result_t result,
+ int priority)
{
register wait_queue_t wq;
register int index;
+ if(event == NO_EVENT)
+ panic("thread_wakeup_prim() called with NO_EVENT");
+
index = wait_hash(event);
wq = &wait_queues[index];
if (one_thread)
- return (wait_queue_wakeup_one(wq, event, result));
+ return (wait_queue_wakeup_one(wq, event, result, priority));
else
return (wait_queue_wakeup_all(wq, event, result));
}
/*
* thread_bind:
*
- * Force a thread to execute on the specified processor.
+ * Force the current thread to execute on the specified processor.
+ * Takes effect after the next thread_block().
*
* Returns the previous binding. PROCESSOR_NULL means
* not bound.
*/
processor_t
thread_bind(
- register thread_t thread,
- processor_t processor)
+ processor_t processor)
{
+ thread_t self = current_thread();
processor_t prev;
- run_queue_t runq = RUN_QUEUE_NULL;
spl_t s;
s = splsched();
- thread_lock(thread);
- prev = thread->bound_processor;
- if (prev != PROCESSOR_NULL)
- runq = run_queue_remove(thread);
+ thread_lock(self);
- thread->bound_processor = processor;
+ /* <rdar://problem/15102234> */
+ assert(self->sched_pri < BASEPRI_RTQUEUES);
- if (runq != RUN_QUEUE_NULL)
- thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
- thread_unlock(thread);
+ prev = self->bound_processor;
+ self->bound_processor = processor;
+
+ thread_unlock(self);
splx(s);
return (prev);
}
-struct {
- uint32_t idle_pset_last,
- idle_pset_any,
- idle_bound;
+/* Invoked prior to idle entry to determine if, on SMT capable processors, an SMT
+ * rebalancing opportunity exists when a core is (instantaneously) idle, but
+ * other SMT-capable cores may be over-committed. TODO: some possible negatives:
+ * IPI thrash if this core does not remain idle following the load balancing ASTs
+ * Idle "thrash", when IPI issue is followed by idle entry/core power down
+ * followed by a wakeup shortly thereafter.
+ */
+
+/* Invoked with pset locked, returns with pset unlocked */
+#if (DEVELOPMENT || DEBUG)
+int sched_smt_balance = 1;
+#endif
+
+static void
+sched_SMT_balance(processor_t cprocessor, processor_set_t cpset) {
+ processor_t ast_processor = NULL;
+
+#if (DEVELOPMENT || DEBUG)
+ if (__improbable(sched_smt_balance == 0))
+ goto smt_balance_exit;
+#endif
+
+ assert(cprocessor == current_processor());
+ if (cprocessor->is_SMT == FALSE)
+ goto smt_balance_exit;
+
+ processor_t sib_processor = cprocessor->processor_secondary ? cprocessor->processor_secondary : cprocessor->processor_primary;
- uint32_t pset_self,
- pset_last,
- pset_other,
- bound_self,
- bound_other;
+ /* Determine if both this processor and its sibling are idle,
+ * indicating an SMT rebalancing opportunity.
+ */
+ if (sib_processor->state != PROCESSOR_IDLE)
+ goto smt_balance_exit;
+
+ processor_t sprocessor;
+
+ sprocessor = (processor_t)queue_first(&cpset->active_queue);
+
+ while (!queue_end(&cpset->active_queue, (queue_entry_t)sprocessor)) {
+ if ((sprocessor->state == PROCESSOR_RUNNING) &&
+ (sprocessor->processor_primary != sprocessor) &&
+ (sprocessor->processor_primary->state == PROCESSOR_RUNNING) &&
+ (sprocessor->current_pri < BASEPRI_RTQUEUES) &&
+ ((cpset->pending_AST_cpu_mask & (1U << sprocessor->cpu_id)) == 0)) {
+ assert(sprocessor != cprocessor);
+ ast_processor = sprocessor;
+ break;
+ }
+ sprocessor = (processor_t)queue_next((queue_entry_t)sprocessor);
+ }
- uint32_t realtime_self,
- realtime_last,
- realtime_other;
+smt_balance_exit:
+ pset_unlock(cpset);
- uint32_t missed_realtime,
- missed_other;
-} dispatch_counts;
+ if (ast_processor) {
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_SMT_BALANCE), ast_processor->cpu_id, ast_processor->state, ast_processor->processor_primary->state, 0, 0);
+ cause_ast_check(ast_processor);
+ }
+}
/*
- * Select a thread for the current processor to run.
+ * thread_select:
+ *
+ * Select a new thread for the current processor to execute.
*
* May select the current thread, which must be locked.
*/
-thread_t
+static thread_t
thread_select(
- register processor_t processor)
+ thread_t thread,
+ processor_t processor,
+ ast_t reason)
{
- register thread_t thread;
- processor_set_t pset;
- boolean_t other_runnable;
+ processor_set_t pset = processor->processor_set;
+ thread_t new_thread = THREAD_NULL;
- /*
- * Check for other non-idle runnable threads.
- */
- pset = processor->processor_set;
- thread = processor->active_thread;
+ assert(processor == current_processor());
- /* Update the thread's priority */
- if (thread->sched_stamp != sched_tick)
- update_priority(thread);
+ do {
+ /*
+ * Update the priority.
+ */
+ if (SCHED(can_update_priority)(thread))
+ SCHED(update_priority)(thread);
+
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
- processor->current_pri = thread->sched_pri;
+ pset_lock(pset);
- simple_lock(&pset->sched_lock);
-
- other_runnable = processor->runq.count > 0 || pset->runq.count > 0;
-
- if ( thread->state == TH_RUN &&
- thread->processor_set == pset &&
- (thread->bound_processor == PROCESSOR_NULL ||
- thread->bound_processor == processor) ) {
- if ( thread->sched_pri >= BASEPRI_RTQUEUES &&
- first_timeslice(processor) ) {
- if (pset->runq.highq >= BASEPRI_RTQUEUES) {
- register run_queue_t runq = &pset->runq;
- register queue_t q;
-
- q = runq->queues + runq->highq;
- if (((thread_t)q->next)->realtime.deadline <
- processor->deadline) {
- thread = (thread_t)q->next;
- ((queue_entry_t)thread)->next->prev = q;
- q->next = ((queue_entry_t)thread)->next;
- thread->runq = RUN_QUEUE_NULL;
- assert(thread->sched_mode & TH_MODE_PREEMPT);
- runq->count--; runq->urgency--;
- if (queue_empty(q)) {
- if (runq->highq != IDLEPRI)
- clrbit(MAXPRI - runq->highq, runq->bitmap);
- runq->highq = MAXPRI - ffsbit(runq->bitmap);
+ assert(processor->state != PROCESSOR_OFF_LINE);
+
+ if (processor->processor_primary != processor) {
+ /*
+ * Should this secondary SMT processor attempt to find work? For pset runqueue systems,
+ * we should look for work only under the same conditions that choose_processor()
+ * would have assigned work, which is when all primary processors have been assigned work.
+ *
+ * An exception is that bound threads are dispatched to a processor without going through
+ * choose_processor(), so in those cases we should continue trying to dequeue work.
+ */
+ if (!SCHED(processor_bound_count)(processor) && !queue_empty(&pset->idle_queue) && !rt_runq.count) {
+ goto idle;
+ }
+ }
+
+ simple_lock(&rt_lock);
+
+ /*
+ * Test to see if the current thread should continue
+ * to run on this processor. Must be runnable, and not
+ * bound to a different processor, nor be in the wrong
+ * processor set.
+ */
+ if (((thread->state & ~TH_SUSP) == TH_RUN) &&
+ (thread->sched_pri >= BASEPRI_RTQUEUES || processor->processor_primary == processor) &&
+ (thread->bound_processor == PROCESSOR_NULL || thread->bound_processor == processor) &&
+ (thread->affinity_set == AFFINITY_SET_NULL || thread->affinity_set->aset_pset == pset)) {
+ if (thread->sched_pri >= BASEPRI_RTQUEUES && first_timeslice(processor)) {
+ if (rt_runq.count > 0) {
+ thread_t next_rt;
+
+ next_rt = (thread_t)queue_first(&rt_runq.queue);
+ if (next_rt->realtime.deadline < processor->deadline &&
+ (next_rt->bound_processor == PROCESSOR_NULL || next_rt->bound_processor == processor)) {
+ thread = (thread_t)dequeue_head(&rt_runq.queue);
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+ rt_runq.count--;
}
}
- }
- processor->deadline = thread->realtime.deadline;
+ simple_unlock(&rt_lock);
- simple_unlock(&pset->sched_lock);
+ processor->deadline = thread->realtime.deadline;
- return (thread);
- }
+ pset_unlock(pset);
- if ( (!other_runnable ||
- (processor->runq.highq < thread->sched_pri &&
- pset->runq.highq < thread->sched_pri)) ) {
+ return (thread);
+ }
- /* I am the highest priority runnable (non-idle) thread */
+ if ((thread->sched_mode != TH_MODE_FAIRSHARE || SCHED(fairshare_runq_count)() == 0) && (rt_runq.count == 0 || BASEPRI_RTQUEUES < thread->sched_pri) && (new_thread = SCHED(choose_thread)(processor, thread->sched_mode == TH_MODE_FAIRSHARE ? MINPRI : thread->sched_pri, reason)) == THREAD_NULL) {
- processor->deadline = UINT64_MAX;
+ simple_unlock(&rt_lock);
- simple_unlock(&pset->sched_lock);
+ /* This thread is still the highest priority runnable (non-idle) thread */
- return (thread);
- }
- }
+ processor->deadline = UINT64_MAX;
- if (other_runnable)
- thread = choose_thread(pset, processor);
- else {
- /*
- * Nothing is runnable, so set this processor idle if it
- * was running. Return its idle thread.
- */
- if (processor->state == PROCESSOR_RUNNING) {
- remqueue(&pset->active_queue, (queue_entry_t)processor);
- processor->state = PROCESSOR_IDLE;
+ pset_unlock(pset);
- enqueue_tail(&pset->idle_queue, (queue_entry_t)processor);
- pset->idle_count++;
+ return (thread);
+ }
}
- processor->deadline = UINT64_MAX;
+ if (new_thread != THREAD_NULL ||
+ (SCHED(processor_queue_has_priority)(processor, rt_runq.count == 0 ? IDLEPRI : BASEPRI_RTQUEUES, TRUE) &&
+ (new_thread = SCHED(choose_thread)(processor, MINPRI, reason)) != THREAD_NULL)) {
+ simple_unlock(&rt_lock);
- thread = processor->idle_thread;
- }
+ processor->deadline = UINT64_MAX;
+ pset_unlock(pset);
- simple_unlock(&pset->sched_lock);
+ return (new_thread);
+ }
- return (thread);
-}
+ if (rt_runq.count > 0) {
+ thread_t next_rt = (thread_t)queue_first(&rt_runq.queue);
-/*
- * Perform a context switch and start executing the new thread.
- *
- * Returns FALSE on failure, and the thread is re-dispatched.
- *
- * Called at splsched.
- */
+ if (__probable((next_rt->bound_processor == NULL || (next_rt->bound_processor == processor)))) {
+ thread = (thread_t)dequeue_head(&rt_runq.queue);
-#define funnel_release_check(thread, debug) \
-MACRO_BEGIN \
- if ((thread)->funnel_state & TH_FN_OWNED) { \
- (thread)->funnel_state = TH_FN_REFUNNEL; \
- KERNEL_DEBUG(0x603242c | DBG_FUNC_NONE, \
- (thread)->funnel_lock, (debug), 0, 0, 0); \
- funnel_unlock((thread)->funnel_lock); \
- } \
-MACRO_END
-
-#define funnel_refunnel_check(thread, debug) \
-MACRO_BEGIN \
- if ((thread)->funnel_state & TH_FN_REFUNNEL) { \
- kern_return_t result = (thread)->wait_result; \
- \
- (thread)->funnel_state = 0; \
- KERNEL_DEBUG(0x6032428 | DBG_FUNC_NONE, \
- (thread)->funnel_lock, (debug), 0, 0, 0); \
- funnel_lock((thread)->funnel_lock); \
- KERNEL_DEBUG(0x6032430 | DBG_FUNC_NONE, \
- (thread)->funnel_lock, (debug), 0, 0, 0); \
- (thread)->funnel_state = TH_FN_OWNED; \
- (thread)->wait_result = result; \
- } \
-MACRO_END
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+ rt_runq.count--;
-boolean_t
-thread_invoke(
- register thread_t old_thread,
- register thread_t new_thread,
- ast_t reason)
-{
- thread_continue_t new_cont, continuation = old_thread->continuation;
- void *new_param, *parameter = old_thread->parameter;
- processor_t processor;
- thread_t prev_thread;
+ simple_unlock(&rt_lock);
- if (get_preemption_level() != 0)
- panic("thread_invoke: preemption_level %d\n",
- get_preemption_level());
+ processor->deadline = thread->realtime.deadline;
+ pset_unlock(pset);
- assert(old_thread == current_thread());
+ return (thread);
+ }
+ }
- /*
- * Mark thread interruptible.
- */
- thread_lock(new_thread);
- new_thread->state &= ~TH_UNINT;
+ simple_unlock(&rt_lock);
- assert(thread_runnable(new_thread));
+ /* No realtime threads and no normal threads on the per-processor
+ * runqueue. Finally check for global fairshare threads.
+ */
+ if ((new_thread = SCHED(fairshare_dequeue)()) != THREAD_NULL) {
- /*
- * Allow time constraint threads to hang onto
- * a stack.
- */
- if ( (old_thread->sched_mode & TH_MODE_REALTIME) &&
- !old_thread->reserved_stack ) {
- old_thread->reserved_stack = old_thread->kernel_stack;
- }
+ processor->deadline = UINT64_MAX;
+ pset_unlock(pset);
+
+ return (new_thread);
+ }
+
+ processor->deadline = UINT64_MAX;
+
+ /*
+ * No runnable threads, attempt to steal
+ * from other processors.
+ */
+ new_thread = SCHED(steal_thread)(pset);
+ if (new_thread != THREAD_NULL) {
+ return (new_thread);
+ }
+
+ /*
+ * If other threads have appeared, shortcut
+ * around again.
+ */
+ if (!SCHED(processor_queue_empty)(processor) || rt_runq.count > 0 || SCHED(fairshare_runq_count)() > 0)
+ continue;
+
+ pset_lock(pset);
+
+ idle:
+ /*
+ * Nothing is runnable, so set this processor idle if it
+ * was running.
+ */
+ if (processor->state == PROCESSOR_RUNNING) {
+ remqueue((queue_entry_t)processor);
+ processor->state = PROCESSOR_IDLE;
+
+ if (processor->processor_primary == processor) {
+ enqueue_head(&pset->idle_queue, (queue_entry_t)processor);
+ }
+ else {
+ enqueue_head(&pset->idle_secondary_queue, (queue_entry_t)processor);
+ }
+ }
+
+ /* Invoked with pset locked, returns with pset unlocked */
+ sched_SMT_balance(processor, pset);
+
+#if CONFIG_SCHED_IDLE_IN_PLACE
+ /*
+ * Choose idle thread if fast idle is not possible.
+ */
+ if (processor->processor_primary != processor)
+ return (processor->idle_thread);
+
+ if ((thread->state & (TH_IDLE|TH_TERMINATE|TH_SUSP)) || !(thread->state & TH_WAIT) || thread->wake_active || thread->sched_pri >= BASEPRI_RTQUEUES)
+ return (processor->idle_thread);
+
+ /*
+ * Perform idling activities directly without a
+ * context switch. Return dispatched thread,
+ * else check again for a runnable thread.
+ */
+ new_thread = thread_select_idle(thread, processor);
+
+#else /* !CONFIG_SCHED_IDLE_IN_PLACE */
+
+ /*
+ * Do a full context switch to idle so that the current
+ * thread can start running on another processor without
+ * waiting for the fast-idled processor to wake up.
+ */
+ return (processor->idle_thread);
+
+#endif /* !CONFIG_SCHED_IDLE_IN_PLACE */
+
+ } while (new_thread == THREAD_NULL);
+
+ return (new_thread);
+}
+
+#if CONFIG_SCHED_IDLE_IN_PLACE
+/*
+ * thread_select_idle:
+ *
+ * Idle the processor using the current thread context.
+ *
+ * Called with thread locked, then dropped and relocked.
+ */
+static thread_t
+thread_select_idle(
+ thread_t thread,
+ processor_t processor)
+{
+ thread_t new_thread;
+ uint64_t arg1, arg2;
+ int urgency;
+
+ if (thread->sched_mode == TH_MODE_TIMESHARE) {
+ if (thread->sched_flags & TH_SFLAG_THROTTLED)
+ sched_background_decr(thread);
+
+ sched_share_decr(thread);
+ }
+ sched_run_decr(thread);
+
+ thread->state |= TH_IDLE;
+ processor->current_pri = IDLEPRI;
+ processor->current_thmode = TH_MODE_NONE;
+ processor->current_sfi_class = SFI_CLASS_KERNEL;
+
+ /* Reload precise timing global policy to thread-local policy */
+ thread->precise_user_kernel_time = use_precise_user_kernel_time(thread);
+
+ thread_unlock(thread);
+
+ /*
+ * Switch execution timing to processor idle thread.
+ */
+ processor->last_dispatch = mach_absolute_time();
+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+ commpage_update_mach_approximate_time(processor->last_dispatch);
+#endif
+
+ thread->last_run_time = processor->last_dispatch;
+ thread_timer_event(processor->last_dispatch, &processor->idle_thread->system_timer);
+ PROCESSOR_DATA(processor, kernel_timer) = &processor->idle_thread->system_timer;
+
+ /*
+ * Cancel the quantum timer while idling.
+ */
+ timer_call_cancel(&processor->quantum_timer);
+ processor->timeslice = 0;
+
+ (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
+
+ thread_tell_urgency(THREAD_URGENCY_NONE, 0, 0, NULL);
+
+ /*
+ * Enable interrupts and perform idling activities. No
+ * preemption due to TH_IDLE being set.
+ */
+ spllo(); new_thread = processor_idle(thread, processor);
+
+ /*
+ * Return at splsched.
+ */
+ (*thread->sched_call)(SCHED_CALL_UNBLOCK, thread);
+
+ thread_lock(thread);
+
+ /*
+ * If awakened, switch to thread timer and start a new quantum.
+ * Otherwise skip; we will context switch to another thread or return here.
+ */
+ if (!(thread->state & TH_WAIT)) {
+ processor->last_dispatch = mach_absolute_time();
+ thread_timer_event(processor->last_dispatch, &thread->system_timer);
+ PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
+
+ thread_quantum_init(thread);
+ processor->quantum_end = processor->last_dispatch + thread->quantum_remaining;
+ timer_call_enter1(&processor->quantum_timer, thread, processor->quantum_end, TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LOCAL);
+ processor->timeslice = 1;
+
+ thread->computation_epoch = processor->last_dispatch;
+ }
+
+ thread->state &= ~TH_IDLE;
+
+ /*
+ * If we idled in place, simulate a context switch back
+ * to the original priority of the thread so that the
+ * platform layer cannot distinguish this from a true
+ * switch to the idle thread.
+ */
+
+ urgency = thread_get_urgency(thread, &arg1, &arg2);
+
+ thread_tell_urgency(urgency, arg1, arg2, new_thread);
+
+ sched_run_incr(thread);
+ if (thread->sched_mode == TH_MODE_TIMESHARE) {
+ sched_share_incr(thread);
+
+ if (thread->sched_flags & TH_SFLAG_THROTTLED)
+ sched_background_incr(thread);
+ }
+
+ return (new_thread);
+}
+#endif /* CONFIG_SCHED_IDLE_IN_PLACE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+static thread_t
+sched_traditional_choose_thread(
+ processor_t processor,
+ int priority,
+ __unused ast_t reason)
+{
+ thread_t thread;
+
+ thread = choose_thread_from_runq(processor, runq_for_processor(processor), priority);
+ if (thread != THREAD_NULL) {
+ runq_consider_decr_bound_count(processor, thread);
+ }
+
+ return thread;
+}
+
+#endif /* defined(CONFIG_SCHED_TRADITIONAL) */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+/*
+ * choose_thread_from_runq:
+ *
+ * Locate a thread to execute from the processor run queue
+ * and return it. Only choose a thread with greater or equal
+ * priority.
+ *
+ * Associated pset must be locked. Returns THREAD_NULL
+ * on failure.
+ */
+thread_t
+choose_thread_from_runq(
+ processor_t processor,
+ run_queue_t rq,
+ int priority)
+{
+ queue_t queue = rq->queues + rq->highq;
+ int pri = rq->highq, count = rq->count;
+ thread_t thread;
+
+ while (count > 0 && pri >= priority) {
+ thread = (thread_t)queue_first(queue);
+ while (!queue_end(queue, (queue_entry_t)thread)) {
+ if (thread->bound_processor == PROCESSOR_NULL ||
+ thread->bound_processor == processor) {
+ remqueue((queue_entry_t)thread);
+
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ rq->count--;
+ if (SCHED(priority_is_urgent)(pri)) {
+ rq->urgency--; assert(rq->urgency >= 0);
+ }
+ if (queue_empty(queue)) {
+ if (pri != IDLEPRI)
+ clrbit(MAXPRI - pri, rq->bitmap);
+ rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ }
+
+ return (thread);
+ }
+ count--;
+
+ thread = (thread_t)queue_next((queue_entry_t)thread);
+ }
+
+ queue--; pri--;
+ }
+
+ return (THREAD_NULL);
+}
+
+#endif /* defined(CONFIG_SCHED_TRADITIONAL) */
+
+/*
+ * Perform a context switch and start executing the new thread.
+ *
+ * Returns FALSE on failure, and the thread is re-dispatched.
+ *
+ * Called at splsched.
+ */
+
+/*
+ * thread_invoke
+ *
+ * "self" is what is currently running on the processor,
+ * "thread" is the new thread to context switch to
+ * (which may be the same thread in some cases)
+ */
+static boolean_t
+thread_invoke(
+ thread_t self,
+ thread_t thread,
+ ast_t reason)
+{
+ thread_continue_t continuation = self->continuation;
+ void *parameter = self->parameter;
+ processor_t processor;
+ uint64_t ctime = mach_absolute_time();
+
+#ifdef CONFIG_MACH_APPROXIMATE_TIME
+ commpage_update_mach_approximate_time(ctime);
+#endif
+
+ if (__improbable(get_preemption_level() != 0)) {
+ int pl = get_preemption_level();
+ panic("thread_invoke: preemption_level %d, possible cause: %s",
+ pl, (pl < 0 ? "unlocking an unlocked mutex or spinlock" :
+ "blocking while holding a spinlock, or within interrupt context"));
+ }
+
+ assert(self == current_thread());
+ assert(self->runq == PROCESSOR_NULL);
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+ sched_traditional_consider_maintenance(ctime);
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+ /*
+ * Mark thread interruptible.
+ */
+ thread_lock(thread);
+ thread->state &= ~TH_UNINT;
+
+ assert(thread_runnable(thread));
+ assert(thread->bound_processor == PROCESSOR_NULL || thread->bound_processor == current_processor());
+ assert(thread->runq == PROCESSOR_NULL);
+
+ /* Reload precise timing global policy to thread-local policy */
+ thread->precise_user_kernel_time = use_precise_user_kernel_time(thread);
+
+ /* Update SFI class based on other factors */
+ thread->sfi_class = sfi_thread_classify(thread);
+
+ /*
+ * Allow time constraint threads to hang onto
+ * a stack.
+ */
+ if ((self->sched_mode == TH_MODE_REALTIME) && !self->reserved_stack)
+ self->reserved_stack = self->kernel_stack;
if (continuation != NULL) {
- if (!new_thread->kernel_stack) {
+ if (!thread->kernel_stack) {
/*
- * If the old thread is using a privileged stack,
+ * If we are using a privileged stack,
* check to see whether we can exchange it with
- * that of the new thread.
+ * that of the other thread.
*/
- if ( old_thread->kernel_stack == old_thread->reserved_stack &&
- !new_thread->reserved_stack)
+ if (self->kernel_stack == self->reserved_stack && !thread->reserved_stack)
goto need_stack;
/*
* Context switch by performing a stack handoff.
*/
- new_cont = new_thread->continuation;
- new_thread->continuation = NULL;
- new_param = new_thread->parameter;
- new_thread->parameter = NULL;
+ continuation = thread->continuation;
+ parameter = thread->parameter;
processor = current_processor();
- processor->active_thread = new_thread;
- processor->current_pri = new_thread->sched_pri;
- new_thread->last_processor = processor;
- ast_context(new_thread);
- thread_unlock(new_thread);
-
- current_task()->csw++;
-
- old_thread->reason = reason;
-
- processor->last_dispatch = mach_absolute_time();
- timer_event((uint32_t)processor->last_dispatch,
- &new_thread->system_timer);
-
- thread_done(old_thread, new_thread, processor);
+ processor->active_thread = thread;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ if (thread->last_processor != processor && thread->last_processor != NULL) {
+ if (thread->last_processor->processor_set != processor->processor_set)
+ thread->ps_switch++;
+ thread->p_switch++;
+ }
+ thread->last_processor = processor;
+ thread->c_switch++;
+ ast_context(thread);
+ thread_unlock(thread);
- machine_stack_handoff(old_thread, new_thread);
+ self->reason = reason;
- thread_begin(new_thread, processor);
+ processor->last_dispatch = ctime;
+ self->last_run_time = ctime;
+ thread_timer_event(ctime, &thread->system_timer);
+ PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
/*
- * Now dispatch the old thread.
+ * Since non-precise user/kernel time doesn't update the state timer
+ * during privilege transitions, synthesize an event now.
*/
- thread_dispatch(old_thread);
+ if (!thread->precise_user_kernel_time) {
+ timer_switch(PROCESSOR_DATA(processor, current_state),
+ ctime,
+ PROCESSOR_DATA(processor, current_state));
+ }
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_STACK_HANDOFF)|DBG_FUNC_NONE,
+ self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
+ if ((thread->chosen_processor != processor) && (thread->chosen_processor != PROCESSOR_NULL)) {
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_MOVED)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), (uintptr_t)thread->chosen_processor->cpu_id, 0, 0, 0);
+ }
+
+ DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
- counter_always(c_thread_invoke_hits++);
+ SCHED_STATS_CSW(processor, self->reason, self->sched_pri, thread->sched_pri);
+
+ TLOG(1, "thread_invoke: calling stack_handoff\n");
+ stack_handoff(self, thread);
+
+ DTRACE_SCHED(on__cpu);
+
+ thread_dispatch(self, thread);
+
+ thread->continuation = thread->parameter = NULL;
+
+ counter(c_thread_invoke_hits++);
- funnel_refunnel_check(new_thread, 2);
(void) spllo();
- assert(new_cont);
- call_continuation(new_cont, new_param, new_thread->wait_result);
+ assert(continuation);
+ call_continuation(continuation, parameter, thread->wait_result);
/*NOTREACHED*/
}
- else
- if (new_thread == old_thread) {
+ else if (thread == self) {
/* same thread but with continuation */
+ ast_context(self);
counter(++c_thread_invoke_same);
- thread_unlock(new_thread);
+ thread_unlock(self);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+ self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
+ self->continuation = self->parameter = NULL;
- funnel_refunnel_check(new_thread, 3);
(void) spllo();
- call_continuation(continuation, parameter, new_thread->wait_result);
+ call_continuation(continuation, parameter, self->wait_result);
/*NOTREACHED*/
}
}
else {
/*
- * Check that the new thread has a stack
+ * Check that the other thread has a stack
*/
- if (!new_thread->kernel_stack) {
+ if (!thread->kernel_stack) {
need_stack:
- if (!stack_alloc_try(new_thread)) {
- counter_always(c_thread_invoke_misses++);
- thread_unlock(new_thread);
- thread_stack_enqueue(new_thread);
+ if (!stack_alloc_try(thread)) {
+ counter(c_thread_invoke_misses++);
+ thread_unlock(thread);
+ thread_stack_enqueue(thread);
return (FALSE);
}
}
- else
- if (new_thread == old_thread) {
+ else if (thread == self) {
+ ast_context(self);
counter(++c_thread_invoke_same);
- thread_unlock(new_thread);
+ thread_unlock(self);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+ self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
return (TRUE);
}
}
* Context switch by full context save.
*/
processor = current_processor();
- processor->active_thread = new_thread;
- processor->current_pri = new_thread->sched_pri;
- new_thread->last_processor = processor;
- ast_context(new_thread);
- assert(thread_runnable(new_thread));
- thread_unlock(new_thread);
-
- counter_always(c_thread_invoke_csw++);
- current_task()->csw++;
+ processor->active_thread = thread;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ if (thread->last_processor != processor && thread->last_processor != NULL) {
+ if (thread->last_processor->processor_set != processor->processor_set)
+ thread->ps_switch++;
+ thread->p_switch++;
+ }
+ thread->last_processor = processor;
+ thread->c_switch++;
+ ast_context(thread);
+ thread_unlock(thread);
- assert(old_thread->runq == RUN_QUEUE_NULL);
- old_thread->reason = reason;
+ counter(c_thread_invoke_csw++);
- processor->last_dispatch = mach_absolute_time();
- timer_event((uint32_t)processor->last_dispatch, &new_thread->system_timer);
+ assert(self->runq == PROCESSOR_NULL);
+ self->reason = reason;
- thread_done(old_thread, new_thread, processor);
+ processor->last_dispatch = ctime;
+ self->last_run_time = ctime;
+ thread_timer_event(ctime, &thread->system_timer);
+ PROCESSOR_DATA(processor, kernel_timer) = &thread->system_timer;
/*
- * This is where we actually switch register context,
- * and address space if required. Control will not
- * return here immediately.
+ * Since non-precise user/kernel time doesn't update the state timer
+ * during privilege transitions, synthesize an event now.
*/
- prev_thread = machine_switch_context(old_thread, continuation, new_thread);
+ if (!thread->precise_user_kernel_time) {
+ timer_switch(PROCESSOR_DATA(processor, current_state),
+ ctime,
+ PROCESSOR_DATA(processor, current_state));
+ }
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_SCHED) | DBG_FUNC_NONE,
+ self->reason, (uintptr_t)thread_tid(thread), self->sched_pri, thread->sched_pri, 0);
+
+ if ((thread->chosen_processor != processor) && (thread->chosen_processor != NULL)) {
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_MOVED)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), (uintptr_t)thread->chosen_processor->cpu_id, 0, 0, 0);
+ }
+
+ DTRACE_SCHED2(off__cpu, struct thread *, thread, struct proc *, thread->task->bsd_info);
+
+ SCHED_STATS_CSW(processor, self->reason, self->sched_pri, thread->sched_pri);
/*
- * We are still old_thread, possibly on a different processor,
- * and new_thread is now stale.
+ * This is where we actually switch register context,
+ * and address space if required. We will next run
+ * as a result of a subsequent context switch.
*/
- thread_begin(old_thread, old_thread->last_processor);
+ assert(continuation == self->continuation);
+ thread = machine_switch_context(self, continuation, thread);
+ assert(self == current_thread());
+ TLOG(1,"thread_invoke: returning machine_switch_context: self %p continuation %p thread %p\n", self, continuation, thread);
+
+ DTRACE_SCHED(on__cpu);
/*
- * Now dispatch the thread which resumed us.
+ * We have been resumed and are set to run.
*/
- thread_dispatch(prev_thread);
+ thread_dispatch(thread, self);
if (continuation) {
- funnel_refunnel_check(old_thread, 3);
+ self->continuation = self->parameter = NULL;
+
(void) spllo();
- call_continuation(continuation, parameter, old_thread->wait_result);
+ call_continuation(continuation, parameter, self->wait_result);
/*NOTREACHED*/
}
}
/*
- * thread_done:
+ * thread_dispatch:
+ *
+ * Handle threads at context switch. Re-dispatch other thread
+ * if still running, otherwise update run state and perform
+ * special actions. Update quantum for other thread and begin
+ * the quantum for ourselves.
*
- * Perform calculations for thread
- * finishing execution on the current processor.
+ * "self" is our new current thread that we have context switched
+ * to, "thread" is the old thread that we have switched away from.
*
* Called at splsched.
*/
void
-thread_done(
- thread_t old_thread,
- thread_t new_thread,
- processor_t processor)
+thread_dispatch(
+ thread_t thread,
+ thread_t self)
{
- if (!(old_thread->state & TH_IDLE)) {
+ processor_t processor = self->last_processor;
+
+ if (thread != THREAD_NULL) {
/*
- * Compute remainder of current quantum.
+ * If blocked at a continuation, discard
+ * the stack.
*/
- if ( first_timeslice(processor) &&
- processor->quantum_end > processor->last_dispatch )
- old_thread->current_quantum =
- (processor->quantum_end - processor->last_dispatch);
- else
- old_thread->current_quantum = 0;
+ if (thread->continuation != NULL && thread->kernel_stack != 0)
+ stack_free(thread);
+
+ if (!(thread->state & TH_IDLE)) {
+ int64_t consumed;
+ int64_t remainder = 0;
+
+ if (processor->quantum_end > processor->last_dispatch)
+ remainder = processor->quantum_end -
+ processor->last_dispatch;
+
+ consumed = thread->quantum_remaining - remainder;
+
+ if ((thread->reason & AST_LEDGER) == 0) {
+ /*
+ * Bill CPU time to both the task and
+ * the individual thread.
+ */
+ ledger_credit(thread->t_ledger,
+ task_ledgers.cpu_time, consumed);
+ ledger_credit(thread->t_threadledger,
+ thread_ledgers.cpu_time, consumed);
+#ifdef CONFIG_BANK
+ if (thread->t_bankledger) {
+ ledger_credit(thread->t_bankledger,
+ bank_ledgers.cpu_time,
+ (consumed - thread->t_deduct_bank_ledger_time));
+
+ }
+ thread->t_deduct_bank_ledger_time =0;
+#endif
+ }
+
+ wake_lock(thread);
+ thread_lock(thread);
- if (old_thread->sched_mode & TH_MODE_REALTIME) {
/*
- * Cancel the deadline if the thread has
- * consumed the entire quantum.
+ * Compute remainder of current quantum.
*/
- if (old_thread->current_quantum == 0) {
- old_thread->realtime.deadline = UINT64_MAX;
- old_thread->reason |= AST_QUANTUM;
+ if (first_timeslice(processor) &&
+ processor->quantum_end > processor->last_dispatch)
+ thread->quantum_remaining = (uint32_t)remainder;
+ else
+ thread->quantum_remaining = 0;
+
+ if (thread->sched_mode == TH_MODE_REALTIME) {
+ /*
+ * Cancel the deadline if the thread has
+ * consumed the entire quantum.
+ */
+ if (thread->quantum_remaining == 0) {
+ thread->realtime.deadline = UINT64_MAX;
+ }
+ } else {
+#if defined(CONFIG_SCHED_TRADITIONAL)
+ /*
+ * For non-realtime threads treat a tiny
+ * remaining quantum as an expired quantum
+ * but include what's left next time.
+ */
+ if (thread->quantum_remaining < min_std_quantum) {
+ thread->reason |= AST_QUANTUM;
+ thread->quantum_remaining += SCHED(initial_quantum_size)(thread);
+ }
+#endif
}
- }
- else {
+
/*
- * For non-realtime threads treat a tiny
- * remaining quantum as an expired quantum
- * but include what's left next time.
+ * If we are doing a direct handoff then
+ * take the remainder of the quantum.
*/
- if (old_thread->current_quantum < min_std_quantum) {
- old_thread->reason |= AST_QUANTUM;
- old_thread->current_quantum += std_quantum;
+ if ((thread->reason & (AST_HANDOFF|AST_QUANTUM)) == AST_HANDOFF) {
+ self->quantum_remaining = thread->quantum_remaining;
+ thread->reason |= AST_QUANTUM;
+ thread->quantum_remaining = 0;
+ } else {
+#if defined(CONFIG_SCHED_MULTIQ)
+ if (sched_groups_enabled && thread->sched_group == self->sched_group) {
+ /* TODO: Remove tracepoint */
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_QUANTUM_HANDOFF) | DBG_FUNC_NONE,
+ self->reason, (uintptr_t)thread_tid(thread),
+ self->quantum_remaining, thread->quantum_remaining, 0);
+
+ self->quantum_remaining = thread->quantum_remaining;
+ thread->quantum_remaining = 0;
+ /* TODO: Should we set AST_QUANTUM here? */
+ }
+#endif /* defined(CONFIG_SCHED_MULTIQ) */
}
- }
- /*
- * If we are doing a direct handoff then
- * give the remainder of our quantum to
- * the next thread.
- */
- if ((old_thread->reason & (AST_HANDOFF|AST_QUANTUM)) == AST_HANDOFF) {
- new_thread->current_quantum = old_thread->current_quantum;
- old_thread->reason |= AST_QUANTUM;
- old_thread->current_quantum = 0;
- }
+ thread->computation_metered += (processor->last_dispatch - thread->computation_epoch);
- old_thread->last_switch = processor->last_dispatch;
+ if ((thread->rwlock_count != 0) && !(LcksOpts & disLkRWPrio)) {
+ integer_t priority;
- old_thread->computation_metered +=
- (old_thread->last_switch - old_thread->computation_epoch);
- }
-}
+ priority = thread->sched_pri;
-/*
- * thread_begin:
- *
- * Set up for thread beginning execution on
- * the current processor.
- *
- * Called at splsched.
- */
-void
-thread_begin(
- thread_t thread,
- processor_t processor)
-{
- if (!(thread->state & TH_IDLE)) {
- /*
- * Give the thread a new quantum
- * if none remaining.
- */
- if (thread->current_quantum == 0)
- thread_quantum_init(thread);
+ if (priority < thread->priority)
+ priority = thread->priority;
+ if (priority < BASEPRI_BACKGROUND)
+ priority = BASEPRI_BACKGROUND;
- /*
- * Set up quantum timer and timeslice.
- */
- processor->quantum_end =
- (processor->last_dispatch + thread->current_quantum);
- timer_call_enter1(&processor->quantum_timer,
- thread, processor->quantum_end);
+ if ((thread->sched_pri < priority) || !(thread->sched_flags & TH_SFLAG_RW_PROMOTED)) {
+ KERNEL_DEBUG_CONSTANT(
+ MACHDBG_CODE(DBG_MACH_SCHED, MACH_RW_PROMOTE) | DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), thread->sched_pri, thread->priority, priority, 0);
- processor_timeslice_setup(processor, thread);
+ thread->sched_flags |= TH_SFLAG_RW_PROMOTED;
- thread->last_switch = processor->last_dispatch;
+ if (thread->sched_pri < priority)
+ set_sched_pri(thread, priority);
+ }
+ }
- thread->computation_epoch = thread->last_switch;
- }
- else {
- timer_call_cancel(&processor->quantum_timer);
- processor->timeslice = 1;
- }
-}
+ if (!(thread->state & TH_WAIT)) {
+ /*
+ * Still running.
+ */
+ if (thread->reason & AST_QUANTUM)
+ thread_setrun(thread, SCHED_TAILQ);
+ else
+ if (thread->reason & AST_PREEMPT)
+ thread_setrun(thread, SCHED_HEADQ);
+ else
+ thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
-/*
- * thread_dispatch:
- *
- * Handle previous thread at context switch. Re-dispatch
- * if still running, otherwise update run state and perform
- * special actions.
- *
- * Called at splsched.
- */
-void
-thread_dispatch(
- register thread_t thread)
-{
- /*
- * If blocked at a continuation, discard
- * the stack.
- */
-#ifndef i386
- if (thread->continuation != NULL && thread->kernel_stack)
- stack_free(thread);
-#endif
+ thread->reason = AST_NONE;
- if (!(thread->state & TH_IDLE)) {
- wake_lock(thread);
- thread_lock(thread);
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_DISPATCH) | DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), thread->reason, thread->state, sched_run_count, 0);
+
+ if (thread->wake_active) {
+ thread->wake_active = FALSE;
+ thread_unlock(thread);
- if (!(thread->state & TH_WAIT)) {
- /*
- * Still running.
- */
- if (thread->reason & AST_QUANTUM)
- thread_setrun(thread, SCHED_TAILQ);
- else
- if (thread->reason & AST_PREEMPT)
- thread_setrun(thread, SCHED_HEADQ);
- else
- thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
+ thread_wakeup(&thread->wake_active);
+ }
+ else
+ thread_unlock(thread);
- thread->reason = AST_NONE;
+ wake_unlock(thread);
+ }
+ else {
+ /*
+ * Waiting.
+ */
+ boolean_t should_terminate = FALSE;
+ uint32_t new_run_count;
- thread_unlock(thread);
- wake_unlock(thread);
- }
- else {
- boolean_t wake;
+ /* Only the first call to thread_dispatch
+ * after explicit termination should add
+ * the thread to the termination queue
+ */
+ if ((thread->state & (TH_TERMINATE|TH_TERMINATE2)) == TH_TERMINATE) {
+ should_terminate = TRUE;
+ thread->state |= TH_TERMINATE2;
+ }
- /*
- * Waiting.
- */
- thread->state &= ~TH_RUN;
+ thread->state &= ~TH_RUN;
+ thread->chosen_processor = PROCESSOR_NULL;
- wake = thread->wake_active;
- thread->wake_active = FALSE;
+ if (thread->sched_mode == TH_MODE_TIMESHARE) {
+ if (thread->sched_flags & TH_SFLAG_THROTTLED)
+ sched_background_decr(thread);
- if (thread->sched_mode & TH_MODE_TIMESHARE)
- pset_share_decr(thread->processor_set);
- pset_run_decr(thread->processor_set);
+ sched_share_decr(thread);
+ }
+ new_run_count = sched_run_decr(thread);
- thread_unlock(thread);
- wake_unlock(thread);
+ if ((thread->state & (TH_WAIT | TH_TERMINATE)) == TH_WAIT) {
+ if (thread->reason & AST_SFI) {
+ thread->wait_sfi_begin_time = processor->last_dispatch;
+ }
+ }
- if (thread->options & TH_OPT_CALLOUT)
- call_thread_block();
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_DISPATCH) | DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), thread->reason, thread->state, new_run_count, 0);
- if (wake)
- thread_wakeup((event_t)&thread->wake_active);
+ (*thread->sched_call)(SCHED_CALL_BLOCK, thread);
- if (thread->state & TH_TERMINATE)
- thread_terminate_enqueue(thread);
+ if (thread->wake_active) {
+ thread->wake_active = FALSE;
+ thread_unlock(thread);
+
+ thread_wakeup(&thread->wake_active);
+ }
+ else
+ thread_unlock(thread);
+
+ wake_unlock(thread);
+
+ if (should_terminate)
+ thread_terminate_enqueue(thread);
+ }
}
}
+
+ if (!(self->state & TH_IDLE)) {
+ uint64_t arg1, arg2;
+ int urgency;
+ ast_t new_ast;
+
+ thread_lock(self);
+ new_ast = sfi_thread_needs_ast(self, NULL);
+ thread_unlock(self);
+
+ if (new_ast != AST_NONE) {
+ ast_on(new_ast);
+ }
+
+ urgency = thread_get_urgency(self, &arg1, &arg2);
+
+ thread_tell_urgency(urgency, arg1, arg2, self);
+
+ /*
+ * Get a new quantum if none remaining.
+ */
+ if (self->quantum_remaining == 0) {
+ thread_quantum_init(self);
+ }
+
+ /*
+ * Set up quantum timer and timeslice.
+ */
+ processor->quantum_end = processor->last_dispatch + self->quantum_remaining;
+ timer_call_enter1(&processor->quantum_timer, self, processor->quantum_end, TIMER_CALL_SYS_CRITICAL | TIMER_CALL_LOCAL);
+
+ processor->timeslice = 1;
+
+ self->computation_epoch = processor->last_dispatch;
+ }
+ else {
+ timer_call_cancel(&processor->quantum_timer);
+ processor->timeslice = 0;
+
+ thread_tell_urgency(THREAD_URGENCY_NONE, 0, 0, NULL);
+ }
}
/*
s = splsched();
- if (!(reason & AST_PREEMPT))
- funnel_release_check(self, 2);
-
processor = current_processor();
- /*
- * Delay switching to the idle thread under certain conditions.
- */
- if (s != FALSE && (self->state & (TH_IDLE|TH_TERMINATE|TH_WAIT)) == TH_WAIT) {
- if ( processor->processor_set->processor_count > 1 &&
- processor->processor_set->runq.count == 0 &&
- processor->runq.count == 0 )
- processor = delay_idle(processor, self);
- }
-
/* If we're explicitly yielding, force a subsequent quantum */
if (reason & AST_YIELD)
processor->timeslice = 0;
self->continuation = continuation;
self->parameter = parameter;
- thread_lock(self);
- new_thread = thread_select(processor);
- assert(new_thread && thread_runnable(new_thread));
- thread_unlock(self);
- while (!thread_invoke(self, new_thread, reason)) {
+ if (self->state & ~(TH_RUN | TH_IDLE)) {
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_BLOCK),
+ reason, VM_KERNEL_UNSLIDE(continuation), 0, 0, 0);
+ }
+
+ do {
thread_lock(self);
- new_thread = thread_select(processor);
- assert(new_thread && thread_runnable(new_thread));
+ new_thread = thread_select(self, processor, reason);
thread_unlock(self);
- }
+ } while (!thread_invoke(self, new_thread, reason));
- funnel_refunnel_check(self, 5);
splx(s);
return (self->wait_result);
{
ast_t handoff = AST_HANDOFF;
- funnel_release_check(self, 3);
-
self->continuation = continuation;
self->parameter = parameter;
while (!thread_invoke(self, new_thread, handoff)) {
- register processor_t processor = current_processor();
+ processor_t processor = current_processor();
thread_lock(self);
- new_thread = thread_select(processor);
+ new_thread = thread_select(self, processor, AST_NONE);
thread_unlock(self);
handoff = AST_NONE;
}
- funnel_refunnel_check(self, 6);
-
return (self->wait_result);
}
*/
void
thread_continue(
- register thread_t old_thread)
+ register thread_t thread)
{
- register thread_t self = current_thread();
+ register thread_t self = current_thread();
register thread_continue_t continuation;
- register void *parameter;
-
+ register void *parameter;
+
+ DTRACE_SCHED(on__cpu);
+
continuation = self->continuation;
- self->continuation = NULL;
parameter = self->parameter;
- self->parameter = NULL;
-
- thread_begin(self, self->last_processor);
- if (old_thread != THREAD_NULL)
- thread_dispatch(old_thread);
+ thread_dispatch(thread, self);
- funnel_refunnel_check(self, 4);
+ self->continuation = self->parameter = NULL;
- if (old_thread != THREAD_NULL)
+ if (thread != THREAD_NULL)
(void)spllo();
+ TLOG(1, "thread_continue: calling call_continuation \n");
call_continuation(continuation, parameter, self->wait_result);
/*NOTREACHED*/
}
+void
+thread_quantum_init(thread_t thread)
+{
+ if (thread->sched_mode == TH_MODE_REALTIME) {
+ thread->quantum_remaining = thread->realtime.computation;
+ } else {
+ thread->quantum_remaining = SCHED(initial_quantum_size)(thread);
+ }
+}
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+uint32_t
+sched_traditional_initial_quantum_size(thread_t thread)
+{
+ if ((thread == THREAD_NULL) || !(thread->sched_flags & TH_SFLAG_THROTTLED))
+ return std_quantum;
+ else
+ return bg_quantum;
+}
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static sched_mode_t
+sched_traditional_initial_thread_sched_mode(task_t parent_task)
+{
+ if (parent_task == kernel_task)
+ return TH_MODE_FIXED;
+ else
+ return TH_MODE_TIMESHARE;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
/*
- * Enqueue thread on run queue. Thread must be locked,
- * and not already be on a run queue. Returns TRUE
- * if a preemption is indicated based on the state
- * of the run queue.
+ * run_queue_init:
*
- * Run queue must be locked, see run_queue_remove()
- * for more info.
+ * Initialize a run queue before first use.
*/
-static boolean_t
+void
+run_queue_init(
+ run_queue_t rq)
+{
+ int i;
+
+ rq->highq = IDLEPRI;
+ for (i = 0; i < NRQBM; i++)
+ rq->bitmap[i] = 0;
+ setbit(MAXPRI - IDLEPRI, rq->bitmap);
+ rq->urgency = rq->count = 0;
+ for (i = 0; i < NRQS; i++)
+ queue_init(&rq->queues[i]);
+}
+
+#if defined(CONFIG_SCHED_FAIRSHARE_CORE)
+int
+sched_traditional_fairshare_runq_count(void)
+{
+ return fs_runq.count;
+}
+
+uint64_t
+sched_traditional_fairshare_runq_stats_count_sum(void)
+{
+ return fs_runq.runq_stats.count_sum;
+}
+
+void
+sched_traditional_fairshare_enqueue(thread_t thread)
+{
+ queue_t queue = &fs_runq.queue;
+
+ simple_lock(&fs_lock);
+
+ enqueue_tail(queue, (queue_entry_t)thread);
+
+ thread->runq = FS_RUNQ;
+ SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+ fs_runq.count++;
+
+ simple_unlock(&fs_lock);
+}
+
+thread_t
+sched_traditional_fairshare_dequeue(void)
+{
+ thread_t thread;
+
+ simple_lock(&fs_lock);
+ if (fs_runq.count > 0) {
+ thread = (thread_t)dequeue_head(&fs_runq.queue);
+
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+ fs_runq.count--;
+
+ simple_unlock(&fs_lock);
+
+ return (thread);
+ }
+ simple_unlock(&fs_lock);
+
+ return THREAD_NULL;
+}
+
+boolean_t
+sched_traditional_fairshare_queue_remove(thread_t thread)
+{
+ queue_t q;
+
+ simple_lock(&fs_lock);
+ q = &fs_runq.queue;
+
+ if (FS_RUNQ == thread->runq) {
+ remqueue((queue_entry_t)thread);
+ SCHED_STATS_RUNQ_CHANGE(&fs_runq.runq_stats, fs_runq.count);
+ fs_runq.count--;
+
+ thread->runq = PROCESSOR_NULL;
+ simple_unlock(&fs_lock);
+ return (TRUE);
+ }
+ else {
+ /*
+ * The thread left the run queue before we could
+ * lock the run queue.
+ */
+ assert(thread->runq == PROCESSOR_NULL);
+ simple_unlock(&fs_lock);
+ return (FALSE);
+ }
+}
+
+#endif /* CONFIG_SCHED_FAIRSHARE_CORE */
+
+/*
+ * run_queue_dequeue:
+ *
+ * Perform a dequeue operation on a run queue,
+ * and return the resulting thread.
+ *
+ * The run queue must be locked (see thread_run_queue_remove()
+ * for more info), and not empty.
+ */
+thread_t
+run_queue_dequeue(
+ run_queue_t rq,
+ integer_t options)
+{
+ thread_t thread;
+ queue_t queue = rq->queues + rq->highq;
+
+ if (options & SCHED_HEADQ) {
+ thread = (thread_t)dequeue_head(queue);
+ }
+ else {
+ thread = (thread_t)dequeue_tail(queue);
+ }
+
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ rq->count--;
+ if (SCHED(priority_is_urgent)(rq->highq)) {
+ rq->urgency--; assert(rq->urgency >= 0);
+ }
+ if (queue_empty(queue)) {
+ if (rq->highq != IDLEPRI)
+ clrbit(MAXPRI - rq->highq, rq->bitmap);
+ rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ }
+
+ return (thread);
+}
+
+/*
+ * run_queue_enqueue:
+ *
+ * Perform a enqueue operation on a run queue.
+ *
+ * The run queue must be locked (see thread_run_queue_remove()
+ * for more info).
+ */
+boolean_t
run_queue_enqueue(
- register run_queue_t rq,
- register thread_t thread,
- integer_t options)
+ run_queue_t rq,
+ thread_t thread,
+ integer_t options)
+{
+ queue_t queue = rq->queues + thread->sched_pri;
+ boolean_t result = FALSE;
+
+ if (queue_empty(queue)) {
+ enqueue_tail(queue, (queue_entry_t)thread);
+
+ setbit(MAXPRI - thread->sched_pri, rq->bitmap);
+ if (thread->sched_pri > rq->highq) {
+ rq->highq = thread->sched_pri;
+ result = TRUE;
+ }
+ } else {
+ if (options & SCHED_TAILQ)
+ enqueue_tail(queue, (queue_entry_t)thread);
+ else
+ enqueue_head(queue, (queue_entry_t)thread);
+ }
+ if (SCHED(priority_is_urgent)(thread->sched_pri))
+ rq->urgency++;
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ rq->count++;
+
+ return (result);
+
+}
+
+/*
+ * run_queue_remove:
+ *
+ * Remove a specific thread from a runqueue.
+ *
+ * The run queue must be locked.
+ */
+void
+run_queue_remove(
+ run_queue_t rq,
+ thread_t thread)
+{
+
+ remqueue((queue_entry_t)thread);
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ rq->count--;
+ if (SCHED(priority_is_urgent)(thread->sched_pri)) {
+ rq->urgency--; assert(rq->urgency >= 0);
+ }
+
+ if (queue_empty(rq->queues + thread->sched_pri)) {
+ /* update run queue status */
+ if (thread->sched_pri != IDLEPRI)
+ clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
+ rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ }
+
+ thread->runq = PROCESSOR_NULL;
+}
+
+/*
+ * fairshare_setrun:
+ *
+ * Dispatch a thread for round-robin execution.
+ *
+ * Thread must be locked. Associated pset must
+ * be locked, and is returned unlocked.
+ */
+static void
+fairshare_setrun(
+ processor_t processor,
+ thread_t thread)
{
- register int whichq = thread->sched_pri;
- register queue_t queue = &rq->queues[whichq];
- boolean_t result = FALSE;
+ processor_set_t pset = processor->processor_set;
+
+ thread->chosen_processor = processor;
+
+ SCHED(fairshare_enqueue)(thread);
- assert(whichq >= MINPRI && whichq <= MAXPRI);
+ pset_unlock(pset);
+
+ if (processor != current_processor())
+ machine_signal_idle(processor);
+
+
+}
+
+/*
+ * realtime_queue_insert:
+ *
+ * Enqueue a thread for realtime execution.
+ */
+static boolean_t
+realtime_queue_insert(
+ thread_t thread)
+{
+ queue_t queue = &rt_runq.queue;
+ uint64_t deadline = thread->realtime.deadline;
+ boolean_t preempt = FALSE;
+
+ simple_lock(&rt_lock);
- assert(thread->runq == RUN_QUEUE_NULL);
if (queue_empty(queue)) {
enqueue_tail(queue, (queue_entry_t)thread);
+ preempt = TRUE;
+ }
+ else {
+ register thread_t entry = (thread_t)queue_first(queue);
- setbit(MAXPRI - whichq, rq->bitmap);
- if (whichq > rq->highq) {
- rq->highq = whichq;
- result = TRUE;
+ while (TRUE) {
+ if ( queue_end(queue, (queue_entry_t)entry) ||
+ deadline < entry->realtime.deadline ) {
+ entry = (thread_t)queue_prev((queue_entry_t)entry);
+ break;
+ }
+
+ entry = (thread_t)queue_next((queue_entry_t)entry);
+ }
+
+ if ((queue_entry_t)entry == queue)
+ preempt = TRUE;
+
+ insque((queue_entry_t)thread, (queue_entry_t)entry);
+ }
+
+ thread->runq = RT_RUNQ;
+ SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+ rt_runq.count++;
+
+ simple_unlock(&rt_lock);
+
+ return (preempt);
+}
+
+/*
+ * realtime_setrun:
+ *
+ * Dispatch a thread for realtime execution.
+ *
+ * Thread must be locked. Associated pset must
+ * be locked, and is returned unlocked.
+ */
+static void
+realtime_setrun(
+ processor_t processor,
+ thread_t thread)
+{
+ processor_set_t pset = processor->processor_set;
+ ast_t preempt;
+
+ boolean_t do_signal_idle = FALSE, do_cause_ast = FALSE;
+
+ thread->chosen_processor = processor;
+
+ /* <rdar://problem/15102234> */
+ assert(thread->bound_processor == PROCESSOR_NULL);
+
+ /*
+ * Dispatch directly onto idle processor.
+ */
+ if ( (thread->bound_processor == processor)
+ && processor->state == PROCESSOR_IDLE) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+
+ processor->next_thread = thread;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = thread->realtime.deadline;
+ processor->state = PROCESSOR_DISPATCHING;
+
+ if (processor != current_processor()) {
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared on exit from main processor_idle() loop */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_signal_idle = TRUE;
+ }
+ }
+ pset_unlock(pset);
+
+ if (do_signal_idle) {
+ machine_signal_idle(processor);
+ }
+ return;
+ }
+
+ if (processor->current_pri < BASEPRI_RTQUEUES)
+ preempt = (AST_PREEMPT | AST_URGENT);
+ else if (thread->realtime.deadline < processor->deadline)
+ preempt = (AST_PREEMPT | AST_URGENT);
+ else
+ preempt = AST_NONE;
+
+ realtime_queue_insert(thread);
+
+ if (preempt != AST_NONE) {
+ if (processor->state == PROCESSOR_IDLE) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+ processor->next_thread = THREAD_NULL;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = thread->realtime.deadline;
+ processor->state = PROCESSOR_DISPATCHING;
+ if (processor == current_processor()) {
+ ast_on(preempt);
+ } else {
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared on exit from main processor_idle() loop */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_signal_idle = TRUE;
+ }
+ }
+ } else if (processor->state == PROCESSOR_DISPATCHING) {
+ if ((processor->next_thread == THREAD_NULL) && ((processor->current_pri < thread->sched_pri) || (processor->deadline > thread->realtime.deadline))) {
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = thread->realtime.deadline;
+ }
+ } else {
+ if (processor == current_processor()) {
+ ast_on(preempt);
+ } else {
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared after IPI causes csw_check() to be called */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_cause_ast = TRUE;
+ }
+ }
+ }
+ } else {
+ /* Selected processor was too busy, just keep thread enqueued and let other processors drain it naturally. */
+ }
+
+ pset_unlock(pset);
+
+ if (do_signal_idle) {
+ machine_signal_idle(processor);
+ } else if (do_cause_ast) {
+ cause_ast_check(processor);
+ }
+}
+
+
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+boolean_t
+priority_is_urgent(int priority)
+{
+ return testbit(priority, sched_preempt_pri) ? TRUE : FALSE;
+}
+
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+/*
+ * processor_enqueue:
+ *
+ * Enqueue thread on a processor run queue. Thread must be locked,
+ * and not already be on a run queue.
+ *
+ * Returns TRUE if a preemption is indicated based on the state
+ * of the run queue.
+ *
+ * The run queue must be locked (see thread_run_queue_remove()
+ * for more info).
+ */
+static boolean_t
+processor_enqueue(
+ processor_t processor,
+ thread_t thread,
+ integer_t options)
+{
+ run_queue_t rq = runq_for_processor(processor);
+ boolean_t result;
+
+ result = run_queue_enqueue(rq, thread, options);
+ thread->runq = processor;
+ runq_consider_incr_bound_count(processor, thread);
+
+ return (result);
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+/*
+ * processor_setrun:
+ *
+ * Dispatch a thread for execution on a
+ * processor.
+ *
+ * Thread must be locked. Associated pset must
+ * be locked, and is returned unlocked.
+ */
+static void
+processor_setrun(
+ processor_t processor,
+ thread_t thread,
+ integer_t options)
+{
+ processor_set_t pset = processor->processor_set;
+ ast_t preempt;
+ enum { eExitIdle, eInterruptRunning, eDoNothing } ipi_action = eDoNothing;
+
+ boolean_t do_signal_idle = FALSE, do_cause_ast = FALSE;
+
+ thread->chosen_processor = processor;
+
+ /*
+ * Dispatch directly onto idle processor.
+ */
+ if ( (SCHED(direct_dispatch_to_idle_processors) ||
+ thread->bound_processor == processor)
+ && processor->state == PROCESSOR_IDLE) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+
+ processor->next_thread = thread;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = UINT64_MAX;
+ processor->state = PROCESSOR_DISPATCHING;
+
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared on exit from main processor_idle() loop */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_signal_idle = TRUE;
+ }
+
+ pset_unlock(pset);
+ if (do_signal_idle) {
+ machine_signal_idle(processor);
+ }
+
+ return;
+ }
+
+ /*
+ * Set preemption mode.
+ */
+ if (SCHED(priority_is_urgent)(thread->sched_pri) && thread->sched_pri > processor->current_pri)
+ preempt = (AST_PREEMPT | AST_URGENT);
+ else if(processor->active_thread && thread_eager_preemption(processor->active_thread))
+ preempt = (AST_PREEMPT | AST_URGENT);
+ else if ((thread->sched_mode == TH_MODE_TIMESHARE) && (thread->sched_pri < thread->priority)) {
+ if(SCHED(priority_is_urgent)(thread->priority) && thread->sched_pri > processor->current_pri) {
+ preempt = (options & SCHED_PREEMPT)? AST_PREEMPT: AST_NONE;
+ } else {
+ preempt = AST_NONE;
+ }
+ } else
+ preempt = (options & SCHED_PREEMPT)? AST_PREEMPT: AST_NONE;
+
+ SCHED(processor_enqueue)(processor, thread, options);
+
+ if (preempt != AST_NONE) {
+ if (processor->state == PROCESSOR_IDLE) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+ processor->next_thread = THREAD_NULL;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = UINT64_MAX;
+ processor->state = PROCESSOR_DISPATCHING;
+
+ ipi_action = eExitIdle;
+ } else if ( processor->state == PROCESSOR_DISPATCHING) {
+ if ((processor->next_thread == THREAD_NULL) && (processor->current_pri < thread->sched_pri)) {
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = UINT64_MAX;
+ }
+ } else if ( (processor->state == PROCESSOR_RUNNING ||
+ processor->state == PROCESSOR_SHUTDOWN) &&
+ (thread->sched_pri >= processor->current_pri ||
+ processor->current_thmode == TH_MODE_FAIRSHARE)) {
+ ipi_action = eInterruptRunning;
+ }
+ } else {
+ /*
+ * New thread is not important enough to preempt what is running, but
+ * special processor states may need special handling
+ */
+ if (processor->state == PROCESSOR_SHUTDOWN &&
+ thread->sched_pri >= processor->current_pri ) {
+ ipi_action = eInterruptRunning;
+ } else if ( processor->state == PROCESSOR_IDLE &&
+ processor != current_processor() ) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
+ processor->next_thread = THREAD_NULL;
+ processor->current_pri = thread->sched_pri;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class;
+ processor->deadline = UINT64_MAX;
+ processor->state = PROCESSOR_DISPATCHING;
+
+ ipi_action = eExitIdle;
}
}
+
+ switch (ipi_action) {
+ case eDoNothing:
+ break;
+ case eExitIdle:
+ if (processor == current_processor()) {
+ if (csw_check_locked(processor, pset, AST_NONE) != AST_NONE)
+ ast_on(preempt);
+ } else {
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared on exit from main processor_idle() loop */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_signal_idle = TRUE;
+ }
+ }
+ break;
+ case eInterruptRunning:
+ if (processor == current_processor()) {
+ if (csw_check_locked(processor, pset, AST_NONE) != AST_NONE)
+ ast_on(preempt);
+ } else {
+ if (!(pset->pending_AST_cpu_mask & (1U << processor->cpu_id))) {
+ /* cleared after IPI causes csw_check() to be called */
+ pset->pending_AST_cpu_mask |= (1U << processor->cpu_id);
+ do_cause_ast = TRUE;
+ }
+ }
+ break;
+ }
+
+ pset_unlock(pset);
+
+ if (do_signal_idle) {
+ machine_signal_idle(processor);
+ } else if (do_cause_ast) {
+ cause_ast_check(processor);
+ }
+}
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+static boolean_t
+processor_queue_empty(processor_t processor)
+{
+ return runq_for_processor(processor)->count == 0;
+
+}
+
+static boolean_t
+sched_traditional_with_pset_runqueue_processor_queue_empty(processor_t processor)
+{
+ processor_set_t pset = processor->processor_set;
+ int count = runq_for_processor(processor)->count;
+
+ /*
+ * The pset runq contains the count of all runnable threads
+ * for all processors in the pset. However, for threads that
+ * are bound to another processor, the current "processor"
+ * is not eligible to execute the thread. So we only
+ * include bound threads that our bound to the current
+ * "processor". This allows the processor to idle when the
+ * count of eligible threads drops to 0, even if there's
+ * a runnable thread bound to a different processor in the
+ * shared runq.
+ */
+
+ count -= pset->pset_runq_bound_count;
+ count += processor->runq_bound_count;
+
+ return count == 0;
+}
+
+static ast_t
+processor_csw_check(processor_t processor)
+{
+ run_queue_t runq;
+ boolean_t has_higher;
+
+ assert(processor->active_thread != NULL);
+
+ runq = runq_for_processor(processor);
+ if (first_timeslice(processor)) {
+ has_higher = (runq->highq > processor->current_pri);
+ } else {
+ has_higher = (runq->highq >= processor->current_pri);
+ }
+ if (has_higher) {
+ if (runq->urgency > 0)
+ return (AST_PREEMPT | AST_URGENT);
+
+ if (processor->active_thread && thread_eager_preemption(processor->active_thread))
+ return (AST_PREEMPT | AST_URGENT);
+
+ return AST_PREEMPT;
+ }
+
+ return AST_NONE;
+}
+
+static boolean_t
+processor_queue_has_priority(processor_t processor,
+ int priority,
+ boolean_t gte)
+{
+ if (gte)
+ return runq_for_processor(processor)->highq >= priority;
else
- if (options & SCHED_HEADQ)
- enqueue_head(queue, (queue_entry_t)thread);
+ return runq_for_processor(processor)->highq > priority;
+}
+
+static boolean_t
+should_current_thread_rechoose_processor(processor_t processor)
+{
+ return (processor->current_pri < BASEPRI_RTQUEUES
+ && processor->processor_primary != processor);
+}
+
+static int
+sched_traditional_processor_runq_count(processor_t processor)
+{
+ return runq_for_processor(processor)->count;
+}
+
+static uint64_t
+sched_traditional_processor_runq_stats_count_sum(processor_t processor)
+{
+ return runq_for_processor(processor)->runq_stats.count_sum;
+}
+
+static uint64_t
+sched_traditional_with_pset_runqueue_processor_runq_stats_count_sum(processor_t processor)
+{
+ if (processor->cpu_id == processor->processor_set->cpu_set_low)
+ return runq_for_processor(processor)->runq_stats.count_sum;
else
- enqueue_tail(queue, (queue_entry_t)thread);
+ return 0ULL;
+}
+
+static int
+sched_traditional_processor_bound_count(processor_t processor)
+{
+ return processor->runq_bound_count;
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+/*
+ * choose_next_pset:
+ *
+ * Return the next sibling pset containing
+ * available processors.
+ *
+ * Returns the original pset if none other is
+ * suitable.
+ */
+static processor_set_t
+choose_next_pset(
+ processor_set_t pset)
+{
+ processor_set_t nset = pset;
+
+ do {
+ nset = next_pset(nset);
+ } while (nset->online_processor_count < 1 && nset != pset);
+
+ return (nset);
+}
+
+/*
+ * choose_processor:
+ *
+ * Choose a processor for the thread, beginning at
+ * the pset. Accepts an optional processor hint in
+ * the pset.
+ *
+ * Returns a processor, possibly from a different pset.
+ *
+ * The thread must be locked. The pset must be locked,
+ * and the resulting pset is locked on return.
+ */
+processor_t
+choose_processor(
+ processor_set_t pset,
+ processor_t processor,
+ thread_t thread)
+{
+ processor_set_t nset, cset = pset;
+
+ /*
+ * Prefer the hinted processor, when appropriate.
+ */
+
+ /* Fold last processor hint from secondary processor to its primary */
+ if (processor != PROCESSOR_NULL) {
+ processor = processor->processor_primary;
+ }
+
+ /*
+ * Only consult platform layer if pset is active, which
+ * it may not be in some cases when a multi-set system
+ * is going to sleep.
+ */
+ if (pset->online_processor_count) {
+ if ((processor == PROCESSOR_NULL) || (processor->processor_set == pset && processor->state == PROCESSOR_IDLE)) {
+ processor_t mc_processor = machine_choose_processor(pset, processor);
+ if (mc_processor != PROCESSOR_NULL)
+ processor = mc_processor->processor_primary;
+ }
+ }
+
+ /*
+ * At this point, we may have a processor hint, and we may have
+ * an initial starting pset. If the hint is not in the pset, or
+ * if the hint is for a processor in an invalid state, discard
+ * the hint.
+ */
+ if (processor != PROCESSOR_NULL) {
+ if (processor->processor_set != pset) {
+ processor = PROCESSOR_NULL;
+ } else {
+ switch (processor->state) {
+ case PROCESSOR_START:
+ case PROCESSOR_SHUTDOWN:
+ case PROCESSOR_OFF_LINE:
+ /*
+ * Hint is for a processor that cannot support running new threads.
+ */
+ processor = PROCESSOR_NULL;
+ break;
+ case PROCESSOR_IDLE:
+ /*
+ * Hint is for an idle processor. Assume it is no worse than any other
+ * idle processor. The platform layer had an opportunity to provide
+ * the "least cost idle" processor above.
+ */
+ return (processor);
+ break;
+ case PROCESSOR_RUNNING:
+ case PROCESSOR_DISPATCHING:
+ /*
+ * Hint is for an active CPU. This fast-path allows
+ * realtime threads to preempt non-realtime threads
+ * to regain their previous executing processor.
+ */
+ if ((thread->sched_pri >= BASEPRI_RTQUEUES) &&
+ (processor->current_pri < BASEPRI_RTQUEUES))
+ return (processor);
+
+ /* Otherwise, use hint as part of search below */
+ break;
+ default:
+ processor = PROCESSOR_NULL;
+ break;
+ }
+ }
+ }
+
+ /*
+ * Iterate through the processor sets to locate
+ * an appropriate processor. Seed results with
+ * a last-processor hint, if available, so that
+ * a search must find something strictly better
+ * to replace it.
+ *
+ * A primary/secondary pair of SMT processors are
+ * "unpaired" if the primary is busy but its
+ * corresponding secondary is idle (so the physical
+ * core has full use of its resources).
+ */
+
+ integer_t lowest_priority = MAXPRI + 1;
+ integer_t lowest_unpaired_primary_priority = MAXPRI + 1;
+ integer_t lowest_count = INT_MAX;
+ uint64_t furthest_deadline = 1;
+ processor_t lp_processor = PROCESSOR_NULL;
+ processor_t lp_unpaired_primary_processor = PROCESSOR_NULL;
+ processor_t lp_unpaired_secondary_processor = PROCESSOR_NULL;
+ processor_t lc_processor = PROCESSOR_NULL;
+ processor_t fd_processor = PROCESSOR_NULL;
+
+ if (processor != PROCESSOR_NULL) {
+ /* All other states should be enumerated above. */
+ assert(processor->state == PROCESSOR_RUNNING || processor->state == PROCESSOR_DISPATCHING);
+
+ lowest_priority = processor->current_pri;
+ lp_processor = processor;
+
+ if (processor->current_pri >= BASEPRI_RTQUEUES) {
+ furthest_deadline = processor->deadline;
+ fd_processor = processor;
+ }
+
+ lowest_count = SCHED(processor_runq_count)(processor);
+ lc_processor = processor;
+ }
+
+ do {
- thread->runq = rq;
- if (thread->sched_mode & TH_MODE_PREEMPT)
- rq->urgency++;
- rq->count++;
+ /*
+ * Choose an idle processor, in pset traversal order
+ */
+ if (!queue_empty(&cset->idle_queue))
+ return ((processor_t)queue_first(&cset->idle_queue));
- return (result);
-}
+ /*
+ * Otherwise, enumerate active and idle processors to find candidates
+ * with lower priority/etc.
+ */
-/*
- * Enqueue a thread for realtime execution, similar
- * to above. Handles preemption directly.
- */
-static void
-realtime_schedule_insert(
- register processor_set_t pset,
- register thread_t thread)
-{
- register run_queue_t rq = &pset->runq;
- register int whichq = thread->sched_pri;
- register queue_t queue = &rq->queues[whichq];
- uint64_t deadline = thread->realtime.deadline;
- boolean_t try_preempt = FALSE;
+ processor = (processor_t)queue_first(&cset->active_queue);
+ while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {
- assert(whichq >= BASEPRI_REALTIME && whichq <= MAXPRI);
+ integer_t cpri = processor->current_pri;
+ if (cpri < lowest_priority) {
+ lowest_priority = cpri;
+ lp_processor = processor;
+ }
- assert(thread->runq == RUN_QUEUE_NULL);
- if (queue_empty(queue)) {
- enqueue_tail(queue, (queue_entry_t)thread);
+ if ((cpri >= BASEPRI_RTQUEUES) && (processor->deadline > furthest_deadline)) {
+ furthest_deadline = processor->deadline;
+ fd_processor = processor;
+ }
- setbit(MAXPRI - whichq, rq->bitmap);
- if (whichq > rq->highq)
- rq->highq = whichq;
- try_preempt = TRUE;
- }
- else {
- register thread_t entry = (thread_t)queue_first(queue);
+ integer_t ccount = SCHED(processor_runq_count)(processor);
+ if (ccount < lowest_count) {
+ lowest_count = ccount;
+ lc_processor = processor;
+ }
- while (TRUE) {
- if ( queue_end(queue, (queue_entry_t)entry) ||
- deadline < entry->realtime.deadline ) {
- entry = (thread_t)queue_prev((queue_entry_t)entry);
- break;
+ processor = (processor_t)queue_next((queue_entry_t)processor);
+ }
+
+ /*
+ * For SMT configs, these idle secondary processors must have active primary. Otherwise
+ * the idle primary would have short-circuited the loop above
+ */
+ processor = (processor_t)queue_first(&cset->idle_secondary_queue);
+ while (!queue_end(&cset->idle_secondary_queue, (queue_entry_t)processor)) {
+ processor_t cprimary = processor->processor_primary;
+
+ /* If the primary processor is offline or starting up, it's not a candidate for this path */
+ if (cprimary->state == PROCESSOR_RUNNING || cprimary->state == PROCESSOR_DISPATCHING) {
+ integer_t primary_pri = cprimary->current_pri;
+
+ if (primary_pri < lowest_unpaired_primary_priority) {
+ lowest_unpaired_primary_priority = primary_pri;
+ lp_unpaired_primary_processor = cprimary;
+ lp_unpaired_secondary_processor = processor;
+ }
}
- entry = (thread_t)queue_next((queue_entry_t)entry);
+ processor = (processor_t)queue_next((queue_entry_t)processor);
}
- if ((queue_entry_t)entry == queue)
- try_preempt = TRUE;
- insque((queue_entry_t)thread, (queue_entry_t)entry);
- }
+ if (thread->sched_pri >= BASEPRI_RTQUEUES) {
+
+ /*
+ * For realtime threads, the most important aspect is
+ * scheduling latency, so we attempt to assign threads
+ * to good preemption candidates (assuming an idle primary
+ * processor was not available above).
+ */
- thread->runq = rq;
- assert(thread->sched_mode & TH_MODE_PREEMPT);
- rq->count++; rq->urgency++;
+ if (thread->sched_pri > lowest_unpaired_primary_priority) {
+ /* Move to end of active queue so that the next thread doesn't also pick it */
+ remqueue((queue_entry_t)lp_unpaired_primary_processor);
+ enqueue_tail(&cset->active_queue, (queue_entry_t)lp_unpaired_primary_processor);
+ return lp_unpaired_primary_processor;
+ }
+ if (thread->sched_pri > lowest_priority) {
+ /* Move to end of active queue so that the next thread doesn't also pick it */
+ remqueue((queue_entry_t)lp_processor);
+ enqueue_tail(&cset->active_queue, (queue_entry_t)lp_processor);
+ return lp_processor;
+ }
+ if (thread->realtime.deadline < furthest_deadline)
+ return fd_processor;
- if (try_preempt) {
- register processor_t processor;
+ /*
+ * If all primary and secondary CPUs are busy with realtime
+ * threads with deadlines earlier than us, move on to next
+ * pset.
+ */
+ }
+ else {
- processor = current_processor();
- if ( pset == processor->processor_set &&
- (thread->sched_pri > processor->current_pri ||
- deadline < processor->deadline ) ) {
- dispatch_counts.realtime_self++;
- simple_unlock(&pset->sched_lock);
+ if (thread->sched_pri > lowest_unpaired_primary_priority) {
+ /* Move to end of active queue so that the next thread doesn't also pick it */
+ remqueue((queue_entry_t)lp_unpaired_primary_processor);
+ enqueue_tail(&cset->active_queue, (queue_entry_t)lp_unpaired_primary_processor);
+ return lp_unpaired_primary_processor;
+ }
+ if (thread->sched_pri > lowest_priority) {
+ /* Move to end of active queue so that the next thread doesn't also pick it */
+ remqueue((queue_entry_t)lp_processor);
+ enqueue_tail(&cset->active_queue, (queue_entry_t)lp_processor);
+ return lp_processor;
+ }
- ast_on(AST_PREEMPT | AST_URGENT);
- return;
+ /*
+ * If all primary processor in this pset are running a higher
+ * priority thread, move on to next pset. Only when we have
+ * exhausted this search do we fall back to other heuristics.
+ */
}
- if ( pset->processor_count > 1 ||
- pset != processor->processor_set ) {
- processor_t myprocessor, lastprocessor;
- queue_entry_t next;
+ /*
+ * Move onto the next processor set.
+ */
+ nset = next_pset(cset);
- myprocessor = processor;
- processor = thread->last_processor;
- if ( processor != myprocessor &&
- processor != PROCESSOR_NULL &&
- processor->processor_set == pset &&
- processor->state == PROCESSOR_RUNNING &&
- (thread->sched_pri > processor->current_pri ||
- deadline < processor->deadline ) ) {
- dispatch_counts.realtime_last++;
- cause_ast_check(processor);
- simple_unlock(&pset->sched_lock);
- return;
- }
+ if (nset != pset) {
+ pset_unlock(cset);
- lastprocessor = processor;
- queue = &pset->active_queue;
- processor = (processor_t)queue_first(queue);
- while (!queue_end(queue, (queue_entry_t)processor)) {
- next = queue_next((queue_entry_t)processor);
-
- if ( processor != myprocessor &&
- processor != lastprocessor &&
- (thread->sched_pri > processor->current_pri ||
- deadline < processor->deadline ) ) {
- if (!queue_end(queue, next)) {
- remqueue(queue, (queue_entry_t)processor);
- enqueue_tail(queue, (queue_entry_t)processor);
- }
- dispatch_counts.realtime_other++;
- cause_ast_check(processor);
- simple_unlock(&pset->sched_lock);
- return;
- }
+ cset = nset;
+ pset_lock(cset);
+ }
+ } while (nset != pset);
- processor = (processor_t)next;
- }
+ /*
+ * Make sure that we pick a running processor,
+ * and that the correct processor set is locked.
+ * Since we may have unlock the candidate processor's
+ * pset, it may have changed state.
+ *
+ * All primary processors are running a higher priority
+ * thread, so the only options left are enqueuing on
+ * the secondary processor that would perturb the least priority
+ * primary, or the least busy primary.
+ */
+ do {
+
+ /* lowest_priority is evaluated in the main loops above */
+ if (lp_unpaired_secondary_processor != PROCESSOR_NULL) {
+ processor = lp_unpaired_secondary_processor;
+ lp_unpaired_secondary_processor = PROCESSOR_NULL;
+ } else if (lc_processor != PROCESSOR_NULL) {
+ processor = lc_processor;
+ lc_processor = PROCESSOR_NULL;
+ } else {
+ /*
+ * All processors are executing higher
+ * priority threads, and the lowest_count
+ * candidate was not usable
+ */
+ processor = master_processor;
}
- }
- simple_unlock(&pset->sched_lock);
+ /*
+ * Check that the correct processor set is
+ * returned locked.
+ */
+ if (cset != processor->processor_set) {
+ pset_unlock(cset);
+ cset = processor->processor_set;
+ pset_lock(cset);
+ }
+
+ /*
+ * We must verify that the chosen processor is still available.
+ * master_processor is an exception, since we may need to preempt
+ * a running thread on it during processor shutdown (for sleep),
+ * and that thread needs to be enqueued on its runqueue to run
+ * when the processor is restarted.
+ */
+ if (processor != master_processor && (processor->state == PROCESSOR_SHUTDOWN || processor->state == PROCESSOR_OFF_LINE))
+ processor = PROCESSOR_NULL;
+
+ } while (processor == PROCESSOR_NULL);
+
+ return (processor);
}
/*
* thread_setrun:
*
- * Dispatch thread for execution, directly onto an idle
- * processor if possible. Else put on appropriate run
- * queue. (local if bound, else processor set)
+ * Dispatch thread for execution, onto an idle
+ * processor or run queue, and signal a preemption
+ * as appropriate.
*
* Thread must be locked.
*/
void
thread_setrun(
- register thread_t new_thread,
- integer_t options)
+ thread_t thread,
+ integer_t options)
{
- register processor_t processor;
- register processor_set_t pset;
- register thread_t thread;
- ast_t preempt = (options & SCHED_PREEMPT)?
- AST_PREEMPT: AST_NONE;
+ processor_t processor;
+ processor_set_t pset;
- assert(thread_runnable(new_thread));
+ assert(thread_runnable(thread));
/*
* Update priority if needed.
*/
- if (new_thread->sched_stamp != sched_tick)
- update_priority(new_thread);
+ if (SCHED(can_update_priority)(thread))
+ SCHED(update_priority)(thread);
- /*
- * Check for urgent preemption.
- */
- if (new_thread->sched_mode & TH_MODE_PREEMPT)
- preempt = (AST_PREEMPT | AST_URGENT);
+ thread->sfi_class = sfi_thread_classify(thread);
- assert(new_thread->runq == RUN_QUEUE_NULL);
-
- if ((processor = new_thread->bound_processor) == PROCESSOR_NULL) {
- /*
- * First try to dispatch on
- * the last processor.
- */
- pset = new_thread->processor_set;
- processor = new_thread->last_processor;
- if ( pset->processor_count > 1 &&
- processor != PROCESSOR_NULL &&
- processor->state == PROCESSOR_IDLE ) {
- processor_lock(processor);
- simple_lock(&pset->sched_lock);
- if ( processor->processor_set == pset &&
- processor->state == PROCESSOR_IDLE ) {
- remqueue(&pset->idle_queue, (queue_entry_t)processor);
- pset->idle_count--;
- processor->next_thread = new_thread;
- if (new_thread->sched_pri >= BASEPRI_RTQUEUES)
- processor->deadline = new_thread->realtime.deadline;
- else
- processor->deadline = UINT64_MAX;
- processor->state = PROCESSOR_DISPATCHING;
- dispatch_counts.idle_pset_last++;
- simple_unlock(&pset->sched_lock);
- processor_unlock(processor);
- if (processor != current_processor())
- machine_signal_idle(processor);
- return;
- }
- processor_unlock(processor);
- }
- else
- simple_lock(&pset->sched_lock);
+ assert(thread->runq == PROCESSOR_NULL);
+ if (thread->bound_processor == PROCESSOR_NULL) {
/*
- * Next pick any idle processor
- * in the processor set.
+ * Unbound case.
*/
- if (pset->idle_count > 0) {
- processor = (processor_t)dequeue_head(&pset->idle_queue);
- pset->idle_count--;
- processor->next_thread = new_thread;
- if (new_thread->sched_pri >= BASEPRI_RTQUEUES)
- processor->deadline = new_thread->realtime.deadline;
- else
- processor->deadline = UINT64_MAX;
- processor->state = PROCESSOR_DISPATCHING;
- dispatch_counts.idle_pset_any++;
- simple_unlock(&pset->sched_lock);
- if (processor != current_processor())
- machine_signal_idle(processor);
- return;
- }
+ if (thread->affinity_set != AFFINITY_SET_NULL) {
+ /*
+ * Use affinity set policy hint.
+ */
+ pset = thread->affinity_set->aset_pset;
+ pset_lock(pset);
- if (new_thread->sched_pri >= BASEPRI_RTQUEUES)
- realtime_schedule_insert(pset, new_thread);
- else {
- if (!run_queue_enqueue(&pset->runq, new_thread, options))
- preempt = AST_NONE;
+ processor = SCHED(choose_processor)(pset, PROCESSOR_NULL, thread);
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), (uintptr_t)-1, processor->cpu_id, processor->state, 0);
+ }
+ else
+ if (thread->last_processor != PROCESSOR_NULL) {
/*
- * Update the timesharing quanta.
+ * Simple (last processor) affinity case.
*/
- timeshare_quanta_update(pset);
-
+ processor = thread->last_processor;
+ pset = processor->processor_set;
+ pset_lock(pset);
+ processor = SCHED(choose_processor)(pset, processor, thread);
+
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), thread->last_processor->cpu_id, processor->cpu_id, processor->state, 0);
+ }
+ else {
/*
- * Preempt check.
+ * No Affinity case:
+ *
+ * Utilitize a per task hint to spread threads
+ * among the available processor sets.
*/
- if (preempt != AST_NONE) {
- /*
- * First try the current processor
- * if it is a member of the correct
- * processor set.
- */
- processor = current_processor();
- thread = processor->active_thread;
- if ( pset == processor->processor_set &&
- csw_needed(thread, processor) ) {
- dispatch_counts.pset_self++;
- simple_unlock(&pset->sched_lock);
-
- ast_on(preempt);
- return;
- }
+ task_t task = thread->task;
- /*
- * If that failed and we have other
- * processors available keep trying.
- */
- if ( pset->processor_count > 1 ||
- pset != processor->processor_set ) {
- queue_t queue = &pset->active_queue;
- processor_t myprocessor, lastprocessor;
- queue_entry_t next;
+ pset = task->pset_hint;
+ if (pset == PROCESSOR_SET_NULL)
+ pset = current_processor()->processor_set;
- /*
- * Next try the last processor
- * dispatched on.
- */
- myprocessor = processor;
- processor = new_thread->last_processor;
- if ( processor != myprocessor &&
- processor != PROCESSOR_NULL &&
- processor->processor_set == pset &&
- processor->state == PROCESSOR_RUNNING &&
- new_thread->sched_pri > processor->current_pri ) {
- dispatch_counts.pset_last++;
- cause_ast_check(processor);
- simple_unlock(&pset->sched_lock);
- return;
- }
+ pset = choose_next_pset(pset);
+ pset_lock(pset);
- /*
- * Lastly, pick any other
- * available processor.
- */
- lastprocessor = processor;
- processor = (processor_t)queue_first(queue);
- while (!queue_end(queue, (queue_entry_t)processor)) {
- next = queue_next((queue_entry_t)processor);
-
- if ( processor != myprocessor &&
- processor != lastprocessor &&
- new_thread->sched_pri >
- processor->current_pri ) {
- if (!queue_end(queue, next)) {
- remqueue(queue, (queue_entry_t)processor);
- enqueue_tail(queue, (queue_entry_t)processor);
- }
- dispatch_counts.pset_other++;
- cause_ast_check(processor);
- simple_unlock(&pset->sched_lock);
- return;
- }
-
- processor = (processor_t)next;
- }
- }
- }
+ processor = SCHED(choose_processor)(pset, PROCESSOR_NULL, thread);
+ task->pset_hint = processor->processor_set;
- simple_unlock(&pset->sched_lock);
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), (uintptr_t)-1, processor->cpu_id, processor->state, 0);
}
}
else {
- /*
- * Bound, can only run on bound processor. Have to lock
- * processor here because it may not be the current one.
- */
- processor_lock(processor);
+ /*
+ * Bound case:
+ *
+ * Unconditionally dispatch on the processor.
+ */
+ processor = thread->bound_processor;
pset = processor->processor_set;
- if (pset != PROCESSOR_SET_NULL) {
- simple_lock(&pset->sched_lock);
- if (processor->state == PROCESSOR_IDLE) {
- remqueue(&pset->idle_queue, (queue_entry_t)processor);
- pset->idle_count--;
- processor->next_thread = new_thread;
- processor->deadline = UINT64_MAX;
- processor->state = PROCESSOR_DISPATCHING;
- dispatch_counts.idle_bound++;
- simple_unlock(&pset->sched_lock);
- processor_unlock(processor);
- if (processor != current_processor())
- machine_signal_idle(processor);
- return;
- }
- }
-
- if (!run_queue_enqueue(&processor->runq, new_thread, options))
- preempt = AST_NONE;
+ pset_lock(pset);
- if (preempt != AST_NONE) {
- if (processor == current_processor()) {
- thread = processor->active_thread;
- if (csw_needed(thread, processor)) {
- dispatch_counts.bound_self++;
- ast_on(preempt);
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_CHOOSE_PROCESSOR)|DBG_FUNC_NONE,
+ (uintptr_t)thread_tid(thread), (uintptr_t)-2, processor->cpu_id, processor->state, 0);
+ }
+
+ /*
+ * Dispatch the thread on the choosen processor.
+ * TODO: This should be based on sched_mode, not sched_pri
+ */
+ if (thread->sched_pri >= BASEPRI_RTQUEUES)
+ realtime_setrun(processor, thread);
+ else if (thread->sched_mode == TH_MODE_FAIRSHARE)
+ fairshare_setrun(processor, thread);
+ else
+ processor_setrun(processor, thread, options);
+}
+
+processor_set_t
+task_choose_pset(
+ task_t task)
+{
+ processor_set_t pset = task->pset_hint;
+
+ if (pset != PROCESSOR_SET_NULL)
+ pset = choose_next_pset(pset);
+
+ return (pset);
+}
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+/*
+ * processor_queue_shutdown:
+ *
+ * Shutdown a processor run queue by
+ * re-dispatching non-bound threads.
+ *
+ * Associated pset must be locked, and is
+ * returned unlocked.
+ */
+void
+processor_queue_shutdown(
+ processor_t processor)
+{
+ processor_set_t pset = processor->processor_set;
+ run_queue_t rq = runq_for_processor(processor);
+ queue_t queue = rq->queues + rq->highq;
+ int pri = rq->highq, count = rq->count;
+ thread_t next, thread;
+ queue_head_t tqueue;
+
+ queue_init(&tqueue);
+
+ while (count > 0) {
+ thread = (thread_t)queue_first(queue);
+ while (!queue_end(queue, (queue_entry_t)thread)) {
+ next = (thread_t)queue_next((queue_entry_t)thread);
+
+ if (thread->bound_processor == PROCESSOR_NULL) {
+ remqueue((queue_entry_t)thread);
+
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ runq_consider_decr_bound_count(processor, thread);
+ rq->count--;
+ if (SCHED(priority_is_urgent)(pri)) {
+ rq->urgency--; assert(rq->urgency >= 0);
}
+ if (queue_empty(queue)) {
+ if (pri != IDLEPRI)
+ clrbit(MAXPRI - pri, rq->bitmap);
+ rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ }
+
+ enqueue_tail(&tqueue, (queue_entry_t)thread);
}
- else
- if ( processor->state == PROCESSOR_RUNNING &&
- new_thread->sched_pri > processor->current_pri ) {
- dispatch_counts.bound_other++;
- cause_ast_check(processor);
- }
+ count--;
+
+ thread = next;
}
- if (pset != PROCESSOR_SET_NULL)
- simple_unlock(&pset->sched_lock);
+ queue--; pri--;
+ }
+
+ pset_unlock(pset);
+
+ while ((thread = (thread_t)dequeue_head(&tqueue)) != THREAD_NULL) {
+ thread_lock(thread);
+
+ thread_setrun(thread, SCHED_TAILQ);
- processor_unlock(processor);
+ thread_unlock(thread);
}
}
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
/*
- * Check for a possible preemption point in
- * the (current) thread.
+ * Check for a preemption point in
+ * the current context.
*
- * Called at splsched.
+ * Called at splsched with thread locked.
*/
ast_t
csw_check(
- thread_t thread,
- processor_t processor)
+ processor_t processor,
+ ast_t check_reason)
{
- int current_pri = thread->sched_pri;
- ast_t result = AST_NONE;
- run_queue_t runq;
-
- if (first_timeslice(processor)) {
- runq = &processor->processor_set->runq;
- if (runq->highq >= BASEPRI_RTQUEUES)
- return (AST_PREEMPT | AST_URGENT);
+ processor_set_t pset = processor->processor_set;
+ ast_t result;
- if (runq->highq > current_pri) {
- if (runq->urgency > 0)
- return (AST_PREEMPT | AST_URGENT);
+ pset_lock(pset);
- result |= AST_PREEMPT;
- }
+ /* If we were sent a remote AST and interrupted a running processor, acknowledge it here with pset lock held */
+ pset->pending_AST_cpu_mask &= ~(1U << processor->cpu_id);
- runq = &processor->runq;
- if (runq->highq > current_pri) {
- if (runq->urgency > 0)
- return (AST_PREEMPT | AST_URGENT);
+ result = csw_check_locked(processor, pset, check_reason);
- result |= AST_PREEMPT;
- }
- }
- else {
- runq = &processor->processor_set->runq;
- if (runq->highq >= current_pri) {
- if (runq->urgency > 0)
- return (AST_PREEMPT | AST_URGENT);
+ pset_unlock(pset);
- result |= AST_PREEMPT;
- }
+ return result;
+}
- runq = &processor->runq;
- if (runq->highq >= current_pri) {
- if (runq->urgency > 0)
- return (AST_PREEMPT | AST_URGENT);
+/*
+ * Check for preemption at splsched with
+ * pset and thread locked
+ */
+ast_t
+csw_check_locked(
+ processor_t processor,
+ processor_set_t pset __unused,
+ ast_t check_reason)
+{
+ ast_t result;
+ thread_t thread = processor->active_thread;
- result |= AST_PREEMPT;
+ if (first_timeslice(processor)) {
+ if (rt_runq.count > 0)
+ return (check_reason | AST_PREEMPT | AST_URGENT);
+ }
+ else {
+ if (rt_runq.count > 0) {
+ if (BASEPRI_RTQUEUES > processor->current_pri)
+ return (check_reason | AST_PREEMPT | AST_URGENT);
+ else
+ return (check_reason | AST_PREEMPT);
}
}
+ result = SCHED(processor_csw_check)(processor);
if (result != AST_NONE)
- return (result);
+ return (check_reason | result);
+ if (SCHED(should_current_thread_rechoose_processor)(processor))
+ return (check_reason | AST_PREEMPT);
+
if (thread->state & TH_SUSP)
- result |= AST_PREEMPT;
+ return (check_reason | AST_PREEMPT);
- return (result);
+ /*
+ * Current thread may not need to be preempted, but maybe needs
+ * an SFI wait?
+ */
+ result = sfi_thread_needs_ast(thread, NULL);
+ if (result != AST_NONE)
+ return (check_reason | result);
+
+ return (AST_NONE);
}
/*
*/
void
set_sched_pri(
- thread_t thread,
- int priority)
+ thread_t thread,
+ int priority)
{
- register struct run_queue *rq = run_queue_remove(thread);
-
- if ( !(thread->sched_mode & TH_MODE_TIMESHARE) &&
- (priority >= BASEPRI_PREEMPT ||
- (thread->task_priority < MINPRI_KERNEL &&
- thread->task_priority >= BASEPRI_BACKGROUND &&
- priority > thread->task_priority) ) )
- thread->sched_mode |= TH_MODE_PREEMPT;
- else
- thread->sched_mode &= ~TH_MODE_PREEMPT;
+ boolean_t removed = thread_run_queue_remove(thread);
+ int curgency, nurgency;
+ uint64_t urgency_param1, urgency_param2;
+ thread_t cthread = current_thread();
+ if (thread == cthread) {
+ curgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);
+ }
+
thread->sched_pri = priority;
- if (rq != RUN_QUEUE_NULL)
+
+ if (thread == cthread) {
+ nurgency = thread_get_urgency(thread, &urgency_param1, &urgency_param2);
+/* set_sched_pri doesn't alter RT params. We expect direct base priority/QoS
+ * class alterations from user space to occur relatively infrequently, hence
+ * those are lazily handled. QoS classes have distinct priority bands, and QoS
+ * inheritance is expected to involve priority changes.
+ */
+ if (nurgency != curgency) {
+ thread_tell_urgency(nurgency, urgency_param1, urgency_param2, thread);
+ }
+ }
+
+ if (removed)
thread_setrun(thread, SCHED_PREEMPT | SCHED_TAILQ);
else
if (thread->state & TH_RUN) {
processor_t processor = thread->last_processor;
if (thread == current_thread()) {
- ast_t preempt = csw_check(thread, processor);
+ ast_t preempt;
- if (preempt != AST_NONE)
- ast_on(preempt);
processor->current_pri = priority;
+ processor->current_thmode = thread->sched_mode;
+ processor->current_sfi_class = thread->sfi_class = sfi_thread_classify(thread);
+ if ((preempt = csw_check(processor, AST_NONE)) != AST_NONE)
+ ast_on(preempt);
}
else
if ( processor != PROCESSOR_NULL &&
#endif /* DEBUG */
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
/*
- * run_queue_remove:
+ * Locks the runqueue itself.
+ *
+ * Thread must be locked.
+ */
+static boolean_t
+processor_queue_remove(
+ processor_t processor,
+ thread_t thread)
+{
+ void * rqlock;
+ run_queue_t rq;
+
+ rqlock = &processor->processor_set->sched_lock;
+ rq = runq_for_processor(processor);
+
+ simple_lock(rqlock);
+ if (processor == thread->runq) {
+ /*
+ * Thread is on a run queue and we have a lock on
+ * that run queue.
+ */
+ runq_consider_decr_bound_count(processor, thread);
+ run_queue_remove(rq, thread);
+ }
+ else {
+ /*
+ * The thread left the run queue before we could
+ * lock the run queue.
+ */
+ assert(thread->runq == PROCESSOR_NULL);
+ processor = PROCESSOR_NULL;
+ }
+
+ simple_unlock(rqlock);
+
+ return (processor != PROCESSOR_NULL);
+}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+
+/*
+ * thread_run_queue_remove:
*
* Remove a thread from its current run queue and
- * return the run queue if successful.
+ * return TRUE if successful.
*
* Thread must be locked.
+ *
+ * If thread->runq is PROCESSOR_NULL, the thread will not re-enter the
+ * run queues because the caller locked the thread. Otherwise
+ * the thread is on a run queue, but could be chosen for dispatch
+ * and removed by another processor under a different lock, which
+ * will set thread->runq to PROCESSOR_NULL.
+ *
+ * Hence the thread select path must not rely on anything that could
+ * be changed under the thread lock after calling this function,
+ * most importantly thread->sched_pri.
*/
-run_queue_t
-run_queue_remove(
- thread_t thread)
+boolean_t
+thread_run_queue_remove(
+ thread_t thread)
{
- register run_queue_t rq = thread->runq;
+ boolean_t removed = FALSE;
+ processor_t processor = thread->runq;
- /*
- * If rq is RUN_QUEUE_NULL, the thread will stay out of the
- * run queues because the caller locked the thread. Otherwise
- * the thread is on a run queue, but could be chosen for dispatch
- * and removed.
- */
- if (rq != RUN_QUEUE_NULL) {
- processor_set_t pset = thread->processor_set;
- processor_t processor = thread->bound_processor;
+ if ((thread->state & (TH_RUN|TH_WAIT)) == TH_WAIT) {
+ /* Thread isn't runnable */
+ assert(thread->runq == PROCESSOR_NULL);
+ return FALSE;
+ }
+ if (processor == PROCESSOR_NULL) {
/*
- * The run queues are locked by the pset scheduling
- * lock, except when a processor is off-line the
- * local run queue is locked by the processor lock.
+ * The thread is either not on the runq,
+ * or is in the midst of being removed from the runq.
+ *
+ * runq is set to NULL under the pset lock, not the thread
+ * lock, so the thread may still be in the process of being dequeued
+ * from the runq. It will wait in invoke for the thread lock to be
+ * dropped.
*/
- if (processor != PROCESSOR_NULL) {
- processor_lock(processor);
- pset = processor->processor_set;
- }
- if (pset != PROCESSOR_SET_NULL)
- simple_lock(&pset->sched_lock);
+ return FALSE;
+ }
+
+ if (thread->sched_mode == TH_MODE_FAIRSHARE) {
+ return SCHED(fairshare_queue_remove)(thread);
+ }
+
+ if (thread->sched_pri < BASEPRI_RTQUEUES) {
+ return SCHED(processor_queue_remove)(processor, thread);
+ }
+
+ simple_lock(&rt_lock);
+
+ if (thread->runq != PROCESSOR_NULL) {
+ /*
+ * Thread is on a run queue and we have a lock on
+ * that run queue.
+ */
+
+ assert(thread->runq == RT_RUNQ);
+
+ remqueue((queue_entry_t)thread);
+ SCHED_STATS_RUNQ_CHANGE(&rt_runq.runq_stats, rt_runq.count);
+ rt_runq.count--;
+
+ thread->runq = PROCESSOR_NULL;
+
+ removed = TRUE;
+ }
+
+ simple_unlock(&rt_lock);
+
+ return (removed);
+}
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
+/*
+ * steal_processor_thread:
+ *
+ * Locate a thread to steal from the processor and
+ * return it.
+ *
+ * Associated pset must be locked. Returns THREAD_NULL
+ * on failure.
+ */
+static thread_t
+steal_processor_thread(
+ processor_t processor)
+{
+ run_queue_t rq = runq_for_processor(processor);
+ queue_t queue = rq->queues + rq->highq;
+ int pri = rq->highq, count = rq->count;
+ thread_t thread;
+
+ while (count > 0) {
+ thread = (thread_t)queue_first(queue);
+ while (!queue_end(queue, (queue_entry_t)thread)) {
+ if (thread->bound_processor == PROCESSOR_NULL) {
+ remqueue((queue_entry_t)thread);
+
+ thread->runq = PROCESSOR_NULL;
+ SCHED_STATS_RUNQ_CHANGE(&rq->runq_stats, rq->count);
+ runq_consider_decr_bound_count(processor, thread);
+ rq->count--;
+ if (SCHED(priority_is_urgent)(pri)) {
+ rq->urgency--; assert(rq->urgency >= 0);
+ }
+ if (queue_empty(queue)) {
+ if (pri != IDLEPRI)
+ clrbit(MAXPRI - pri, rq->bitmap);
+ rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ }
- if (rq == thread->runq) {
- /*
- * Thread is on a run queue and we have a lock on
- * that run queue.
- */
- remqueue(&rq->queues[0], (queue_entry_t)thread);
- rq->count--;
- if (thread->sched_mode & TH_MODE_PREEMPT)
- rq->urgency--;
- assert(rq->urgency >= 0);
-
- if (queue_empty(rq->queues + thread->sched_pri)) {
- /* update run queue status */
- if (thread->sched_pri != IDLEPRI)
- clrbit(MAXPRI - thread->sched_pri, rq->bitmap);
- rq->highq = MAXPRI - ffsbit(rq->bitmap);
+ return (thread);
}
+ count--;
- thread->runq = RUN_QUEUE_NULL;
- }
- else {
- /*
- * The thread left the run queue before we could
- * lock the run queue.
- */
- assert(thread->runq == RUN_QUEUE_NULL);
- rq = RUN_QUEUE_NULL;
+ thread = (thread_t)queue_next((queue_entry_t)thread);
}
- if (pset != PROCESSOR_SET_NULL)
- simple_unlock(&pset->sched_lock);
-
- if (processor != PROCESSOR_NULL)
- processor_unlock(processor);
+ queue--; pri--;
}
- return (rq);
+ return (THREAD_NULL);
}
/*
- * choose_thread:
+ * Locate and steal a thread, beginning
+ * at the pset.
*
- * Remove a thread to execute from the run queues
- * and return it.
+ * The pset must be locked, and is returned
+ * unlocked.
*
- * Called with pset scheduling lock held.
+ * Returns the stolen thread, or THREAD_NULL on
+ * failure.
*/
static thread_t
-choose_thread(
- processor_set_t pset,
- processor_t processor)
+steal_thread(
+ processor_set_t pset)
{
- register run_queue_t runq;
- register thread_t thread;
- register queue_t q;
-
- runq = &processor->runq;
+ processor_set_t nset, cset = pset;
+ processor_t processor;
+ thread_t thread;
- if (runq->count > 0 && runq->highq >= pset->runq.highq) {
- q = runq->queues + runq->highq;
+ do {
+ processor = (processor_t)queue_first(&cset->active_queue);
+ while (!queue_end(&cset->active_queue, (queue_entry_t)processor)) {
+ if (runq_for_processor(processor)->count > 0) {
+ thread = steal_processor_thread(processor);
+ if (thread != THREAD_NULL) {
+ remqueue((queue_entry_t)processor);
+ enqueue_tail(&cset->active_queue, (queue_entry_t)processor);
- thread = (thread_t)q->next;
- ((queue_entry_t)thread)->next->prev = q;
- q->next = ((queue_entry_t)thread)->next;
- thread->runq = RUN_QUEUE_NULL;
- runq->count--;
- if (thread->sched_mode & TH_MODE_PREEMPT)
- runq->urgency--;
- assert(runq->urgency >= 0);
- if (queue_empty(q)) {
- if (runq->highq != IDLEPRI)
- clrbit(MAXPRI - runq->highq, runq->bitmap);
- runq->highq = MAXPRI - ffsbit(runq->bitmap);
- }
+ pset_unlock(cset);
- processor->deadline = UINT64_MAX;
+ return (thread);
+ }
+ }
- return (thread);
- }
+ processor = (processor_t)queue_next((queue_entry_t)processor);
+ }
- runq = &pset->runq;
+ nset = next_pset(cset);
- assert(runq->count > 0);
- q = runq->queues + runq->highq;
+ if (nset != pset) {
+ pset_unlock(cset);
- thread = (thread_t)q->next;
- ((queue_entry_t)thread)->next->prev = q;
- q->next = ((queue_entry_t)thread)->next;
- thread->runq = RUN_QUEUE_NULL;
- runq->count--;
- if (runq->highq >= BASEPRI_RTQUEUES)
- processor->deadline = thread->realtime.deadline;
- else
- processor->deadline = UINT64_MAX;
- if (thread->sched_mode & TH_MODE_PREEMPT)
- runq->urgency--;
- assert(runq->urgency >= 0);
- if (queue_empty(q)) {
- if (runq->highq != IDLEPRI)
- clrbit(MAXPRI - runq->highq, runq->bitmap);
- runq->highq = MAXPRI - ffsbit(runq->bitmap);
- }
+ cset = nset;
+ pset_lock(cset);
+ }
+ } while (nset != pset);
- timeshare_quanta_update(pset);
+ pset_unlock(cset);
- return (thread);
+ return (THREAD_NULL);
}
-static processor_t
-delay_idle(
- processor_t processor,
- thread_t self)
+static thread_t steal_thread_disabled(
+ processor_set_t pset)
{
- int *gcount, *lcount;
- uint64_t abstime, spin, limit;
-
- lcount = &processor->runq.count;
- gcount = &processor->processor_set->runq.count;
+ pset_unlock(pset);
- abstime = mach_absolute_time();
- limit = abstime + delay_idle_limit;
- spin = abstime + delay_idle_spin;
-
- timer_event((uint32_t)abstime, &processor->idle_thread->system_timer);
+ return (THREAD_NULL);
+}
- self->options |= TH_OPT_DELAYIDLE;
+#endif /* CONFIG_SCHED_TRADITIONAL */
- while ( *gcount == 0 && *lcount == 0 &&
- (self->state & TH_WAIT) != 0 &&
- abstime < limit ) {
- if (abstime >= spin) {
- (void)spllo();
- (void)splsched();
- processor = current_processor();
- lcount = &processor->runq.count;
- gcount = &processor->processor_set->runq.count;
+void
+sys_override_cpu_throttle(int flag)
+{
+ if (flag == CPU_THROTTLE_ENABLE)
+ cpu_throttle_enabled = 1;
+ if (flag == CPU_THROTTLE_DISABLE)
+ cpu_throttle_enabled = 0;
+}
- abstime = mach_absolute_time();
- spin = abstime + delay_idle_spin;
+int
+thread_get_urgency(thread_t thread, uint64_t *arg1, uint64_t *arg2)
+{
+ if (thread == NULL || (thread->state & TH_IDLE)) {
+ *arg1 = 0;
+ *arg2 = 0;
+
+ return (THREAD_URGENCY_NONE);
+ } else if (thread->sched_mode == TH_MODE_REALTIME) {
+ *arg1 = thread->realtime.period;
+ *arg2 = thread->realtime.deadline;
+
+ return (THREAD_URGENCY_REAL_TIME);
+ } else if (cpu_throttle_enabled &&
+ ((thread->sched_pri <= MAXPRI_THROTTLE) && (thread->priority <= MAXPRI_THROTTLE))) {
+ /*
+ * Background urgency applied when thread priority is MAXPRI_THROTTLE or lower and thread is not promoted
+ * TODO: Use TH_SFLAG_THROTTLED instead?
+ */
+ *arg1 = thread->sched_pri;
+ *arg2 = thread->priority;
- timer_event((uint32_t)abstime, &processor->idle_thread->system_timer);
- }
- else
- abstime = mach_absolute_time();
+ return (THREAD_URGENCY_BACKGROUND);
+ } else {
+ /* For otherwise unclassified threads, report throughput QoS
+ * parameters
+ */
+ *arg1 = thread->effective_policy.t_through_qos;
+ *arg2 = thread->task->effective_policy.t_through_qos;
+
+ return (THREAD_URGENCY_NORMAL);
}
-
- timer_event((uint32_t)abstime, &self->system_timer);
-
- self->options &= ~TH_OPT_DELAYIDLE;
-
- return (processor);
}
-/*
- * no_dispatch_count counts number of times processors go non-idle
- * without being dispatched. This should be very rare.
- */
-int no_dispatch_count = 0;
/*
- * This is the idle processor thread, which just looks for other threads
- * to execute.
+ * This is the processor idle loop, which just looks for other threads
+ * to execute. Processor idle threads invoke this without supplying a
+ * current thread to idle without an asserted wait state.
+ *
+ * Returns a the next thread to execute if dispatched directly.
*/
-void
-idle_thread(void)
+
+#if 0
+#define IDLE_KERNEL_DEBUG_CONSTANT(...) KERNEL_DEBUG_CONSTANT(__VA_ARGS__)
+#else
+#define IDLE_KERNEL_DEBUG_CONSTANT(...) do { } while(0)
+#endif
+
+thread_t
+processor_idle(
+ thread_t thread,
+ processor_t processor)
{
- register processor_t processor;
- register thread_t *threadp;
- register int *gcount;
- register int *lcount;
- register thread_t new_thread;
- register int state;
- register processor_set_t pset;
- ast_t *myast = ast_pending();
+ processor_set_t pset = processor->processor_set;
+ thread_t new_thread;
+ int state;
+ (void)splsched();
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_START,
+ (uintptr_t)thread_tid(thread), 0, 0, 0, 0);
+
+ SCHED_STATS_CPU_IDLE_START(processor);
+
+ timer_switch(&PROCESSOR_DATA(processor, system_state),
+ mach_absolute_time(), &PROCESSOR_DATA(processor, idle_state));
+ PROCESSOR_DATA(processor, current_state) = &PROCESSOR_DATA(processor, idle_state);
+
+ while (1) {
+ if (processor->state != PROCESSOR_IDLE) /* unsafe, but worst case we loop around once */
+ break;
+ if (pset->pending_AST_cpu_mask & (1U << processor->cpu_id))
+ break;
+ if (rt_runq.count)
+ break;
+#if CONFIG_SCHED_IDLE_IN_PLACE
+ if (thread != THREAD_NULL) {
+ /* Did idle-in-place thread wake up */
+ if ((thread->state & (TH_WAIT|TH_SUSP)) != TH_WAIT || thread->wake_active)
+ break;
+ }
+#endif
- processor = current_processor();
+ IDLE_KERNEL_DEBUG_CONSTANT(
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_NONE, (uintptr_t)thread_tid(thread), rt_runq.count, SCHED(processor_runq_count)(processor), -1, 0);
- threadp = &processor->next_thread;
- lcount = &processor->runq.count;
- gcount = &processor->processor_set->runq.count;
+ machine_track_platform_idle(TRUE);
+ machine_idle();
- (void)splsched(); /* Turn interruptions off */
+ machine_track_platform_idle(FALSE);
-#ifdef __ppc__
- pmsDown(); /* Step power down. Note: interruptions must be disabled for this call */
-#endif
+ (void)splsched();
- while ( (*threadp == THREAD_NULL) &&
- (*gcount == 0) && (*lcount == 0) ) {
+ IDLE_KERNEL_DEBUG_CONSTANT(
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_NONE, (uintptr_t)thread_tid(thread), rt_runq.count, SCHED(processor_runq_count)(processor), -2, 0);
- /* check for ASTs while we wait */
- if (*myast &~ (AST_SCHEDULING | AST_BSD)) {
- /* no ASTs for us */
- *myast &= AST_NONE;
- (void)spllo();
+ if (!SCHED(processor_queue_empty)(processor)) {
+ /* Secondary SMT processors respond to directed wakeups
+ * exclusively. Some platforms induce 'spurious' SMT wakeups.
+ */
+ if (processor->processor_primary == processor)
+ break;
}
- else
- machine_idle();
-
- (void)splsched();
}
- /*
- * This is not a switch statement to avoid the
- * bounds checking code in the common case.
- */
- pset = processor->processor_set;
- simple_lock(&pset->sched_lock);
+ timer_switch(&PROCESSOR_DATA(processor, idle_state),
+ mach_absolute_time(), &PROCESSOR_DATA(processor, system_state));
+ PROCESSOR_DATA(processor, current_state) = &PROCESSOR_DATA(processor, system_state);
-#ifdef __ppc__
- pmsStep(0); /* Step up out of idle power, may start timer for next step */
-#endif
+ pset_lock(pset);
+
+ /* If we were sent a remote AST and came out of idle, acknowledge it here with pset lock held */
+ pset->pending_AST_cpu_mask &= ~(1U << processor->cpu_id);
state = processor->state;
if (state == PROCESSOR_DISPATCHING) {
/*
* Commmon case -- cpu dispatched.
*/
- new_thread = *threadp;
- *threadp = (volatile thread_t) THREAD_NULL;
+ new_thread = processor->next_thread;
+ processor->next_thread = THREAD_NULL;
processor->state = PROCESSOR_RUNNING;
- enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
-
- if ( pset->runq.highq >= BASEPRI_RTQUEUES &&
- new_thread->sched_pri >= BASEPRI_RTQUEUES ) {
- register run_queue_t runq = &pset->runq;
- register queue_t q;
-
- q = runq->queues + runq->highq;
- if (((thread_t)q->next)->realtime.deadline <
- processor->deadline) {
- thread_t thread = new_thread;
-
- new_thread = (thread_t)q->next;
- ((queue_entry_t)new_thread)->next->prev = q;
- q->next = ((queue_entry_t)new_thread)->next;
- new_thread->runq = RUN_QUEUE_NULL;
- processor->deadline = new_thread->realtime.deadline;
- assert(new_thread->sched_mode & TH_MODE_PREEMPT);
- runq->count--; runq->urgency--;
- if (queue_empty(q)) {
- if (runq->highq != IDLEPRI)
- clrbit(MAXPRI - runq->highq, runq->bitmap);
- runq->highq = MAXPRI - ffsbit(runq->bitmap);
- }
- dispatch_counts.missed_realtime++;
- simple_unlock(&pset->sched_lock);
-
- thread_lock(thread);
- thread_setrun(thread, SCHED_HEADQ);
- thread_unlock(thread);
-
- counter(c_idle_thread_handoff++);
- thread_run(processor->idle_thread, (thread_continue_t)idle_thread, NULL, new_thread);
- /*NOTREACHED*/
- }
- simple_unlock(&pset->sched_lock);
- counter(c_idle_thread_handoff++);
- thread_run(processor->idle_thread, (thread_continue_t)idle_thread, NULL, new_thread);
- /*NOTREACHED*/
- }
+ if ((new_thread != THREAD_NULL) && (SCHED(processor_queue_has_priority)(processor, new_thread->sched_pri, FALSE) ||
+ (rt_runq.count > 0 && BASEPRI_RTQUEUES >= new_thread->sched_pri)) ) {
+ /* Something higher priority has popped up on the runqueue - redispatch this thread elsewhere */
+ processor->current_pri = IDLEPRI;
+ processor->current_thmode = TH_MODE_FIXED;
+ processor->current_sfi_class = SFI_CLASS_KERNEL;
+ processor->deadline = UINT64_MAX;
- if ( processor->runq.highq > new_thread->sched_pri ||
- pset->runq.highq > new_thread->sched_pri ) {
- thread_t thread = new_thread;
+ pset_unlock(pset);
- new_thread = choose_thread(pset, processor);
- dispatch_counts.missed_other++;
- simple_unlock(&pset->sched_lock);
+ thread_lock(new_thread);
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_REDISPATCH), (uintptr_t)thread_tid(new_thread), new_thread->sched_pri, rt_runq.count, 0, 0);
+ thread_setrun(new_thread, SCHED_HEADQ);
+ thread_unlock(new_thread);
- thread_lock(thread);
- thread_setrun(thread, SCHED_HEADQ);
- thread_unlock(thread);
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END,
+ (uintptr_t)thread_tid(thread), state, 0, 0, 0);
- counter(c_idle_thread_handoff++);
- thread_run(processor->idle_thread, (thread_continue_t)idle_thread, NULL, new_thread);
- /* NOTREACHED */
+ return (THREAD_NULL);
}
- else {
- simple_unlock(&pset->sched_lock);
- counter(c_idle_thread_handoff++);
- thread_run(processor->idle_thread, (thread_continue_t)idle_thread, NULL, new_thread);
- /* NOTREACHED */
- }
+ pset_unlock(pset);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END,
+ (uintptr_t)thread_tid(thread), state, (uintptr_t)thread_tid(new_thread), 0, 0);
+
+ return (new_thread);
}
else
if (state == PROCESSOR_IDLE) {
- /*
- * Processor was not dispatched (Rare).
- * Set it running again and force a
- * reschedule.
- */
- no_dispatch_count++;
- pset->idle_count--;
- remqueue(&pset->idle_queue, (queue_entry_t)processor);
+ remqueue((queue_entry_t)processor);
+
processor->state = PROCESSOR_RUNNING;
+ processor->current_pri = IDLEPRI;
+ processor->current_thmode = TH_MODE_FIXED;
+ processor->current_sfi_class = SFI_CLASS_KERNEL;
+ processor->deadline = UINT64_MAX;
enqueue_tail(&pset->active_queue, (queue_entry_t)processor);
- simple_unlock(&pset->sched_lock);
-
- counter(c_idle_thread_block++);
- thread_block((thread_continue_t)idle_thread);
- /* NOTREACHED */
}
else
if (state == PROCESSOR_SHUTDOWN) {
* Going off-line. Force a
* reschedule.
*/
- if ((new_thread = (thread_t)*threadp) != THREAD_NULL) {
- *threadp = (volatile thread_t) THREAD_NULL;
+ if ((new_thread = processor->next_thread) != THREAD_NULL) {
+ processor->next_thread = THREAD_NULL;
+ processor->current_pri = IDLEPRI;
+ processor->current_thmode = TH_MODE_FIXED;
+ processor->current_sfi_class = SFI_CLASS_KERNEL;
processor->deadline = UINT64_MAX;
- simple_unlock(&pset->sched_lock);
+
+ pset_unlock(pset);
thread_lock(new_thread);
thread_setrun(new_thread, SCHED_HEADQ);
thread_unlock(new_thread);
- }
- else
- simple_unlock(&pset->sched_lock);
- counter(c_idle_thread_block++);
- thread_block((thread_continue_t)idle_thread);
- /* NOTREACHED */
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END,
+ (uintptr_t)thread_tid(thread), state, 0, 0, 0);
+
+ return (THREAD_NULL);
+ }
}
- simple_unlock(&pset->sched_lock);
+ pset_unlock(pset);
+
+ KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
+ MACHDBG_CODE(DBG_MACH_SCHED,MACH_IDLE) | DBG_FUNC_END,
+ (uintptr_t)thread_tid(thread), state, 0, 0, 0);
+
+ return (THREAD_NULL);
+}
+
+/*
+ * Each processor has a dedicated thread which
+ * executes the idle loop when there is no suitable
+ * previous context.
+ */
+void
+idle_thread(void)
+{
+ processor_t processor = current_processor();
+ thread_t new_thread;
+
+ new_thread = processor_idle(THREAD_NULL, processor);
+ if (new_thread != THREAD_NULL) {
+ thread_run(processor->idle_thread, (thread_continue_t)idle_thread, NULL, new_thread);
+ /*NOTREACHED*/
+ }
- panic("idle_thread: state %d\n", processor->state);
+ thread_block((thread_continue_t)idle_thread);
/*NOTREACHED*/
}
processor->idle_thread = thread;
thread->sched_pri = thread->priority = IDLEPRI;
thread->state = (TH_RUN | TH_IDLE);
+ thread->options |= TH_OPT_IDLE_THREAD;
thread_unlock(thread);
splx(s);
return (KERN_SUCCESS);
}
-static uint64_t sched_tick_deadline;
-
/*
* sched_startup:
*
kern_return_t result;
thread_t thread;
- result = kernel_thread_start_priority((thread_continue_t)sched_tick_thread, NULL, MAXPRI_KERNEL, &thread);
+ result = kernel_thread_start_priority((thread_continue_t)sched_init_thread,
+ (void *)SCHED(maintenance_continuation), MAXPRI_KERNEL, &thread);
if (result != KERN_SUCCESS)
panic("sched_startup");
thread_deallocate(thread);
/*
- * Yield to the sched_tick_thread while it times
- * a series of context switches back. It stores
- * the baseline value in sched_cswtime.
+ * Yield to the sched_init_thread once, to
+ * initialize our own thread after being switched
+ * back to.
*
* The current thread is the only other thread
* active at this point.
*/
- while (sched_cswtime == 0)
- thread_block(THREAD_CONTINUE_NULL);
-
- thread_daemon_init();
-
- thread_call_initialize();
+ thread_block(THREAD_CONTINUE_NULL);
}
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
+static volatile uint64_t sched_maintenance_deadline;
+#if defined(CONFIG_TELEMETRY)
+static volatile uint64_t sched_telemetry_deadline = 0;
+#endif
+static uint64_t sched_tick_last_abstime;
+static uint64_t sched_tick_delta;
+uint64_t sched_tick_max_delta;
/*
- * sched_tick_thread:
+ * sched_init_thread:
*
* Perform periodic bookkeeping functions about ten
* times per second.
*/
-static void
-sched_tick_continue(void)
+void
+sched_traditional_maintenance_continue(void)
{
- uint64_t abstime = mach_absolute_time();
+ uint64_t sched_tick_ctime, late_time;
+
+ sched_tick_ctime = mach_absolute_time();
+
+ if (__improbable(sched_tick_last_abstime == 0)) {
+ sched_tick_last_abstime = sched_tick_ctime;
+ late_time = 0;
+ sched_tick_delta = 1;
+ } else {
+ late_time = sched_tick_ctime - sched_tick_last_abstime;
+ sched_tick_delta = late_time / sched_tick_interval;
+ /* Ensure a delta of 1, since the interval could be slightly
+ * smaller than the sched_tick_interval due to dispatch
+ * latencies.
+ */
+ sched_tick_delta = MAX(sched_tick_delta, 1);
+
+ /* In the event interrupt latencies or platform
+ * idle events that advanced the timebase resulted
+ * in periods where no threads were dispatched,
+ * cap the maximum "tick delta" at SCHED_TICK_MAX_DELTA
+ * iterations.
+ */
+ sched_tick_delta = MIN(sched_tick_delta, SCHED_TICK_MAX_DELTA);
- sched_tick++;
+ sched_tick_last_abstime = sched_tick_ctime;
+ sched_tick_max_delta = MAX(sched_tick_delta, sched_tick_max_delta);
+ }
+
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_MAINTENANCE)|DBG_FUNC_START,
+ sched_tick_delta,
+ late_time,
+ 0,
+ 0,
+ 0);
+
+ /* Add a number of pseudo-ticks corresponding to the elapsed interval
+ * This could be greater than 1 if substantial intervals where
+ * all processors are idle occur, which rarely occurs in practice.
+ */
+
+ sched_tick += sched_tick_delta;
/*
* Compute various averages.
*/
- compute_averages();
+ compute_averages(sched_tick_delta);
/*
* Scan the run queues for threads which
* may need to be updated.
*/
- thread_update_scan();
+ SCHED(thread_update_scan)();
- clock_deadline_for_periodic_event(sched_tick_interval, abstime,
- &sched_tick_deadline);
+ KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_MAINTENANCE)|DBG_FUNC_END,
+ sched_pri_shift,
+ sched_background_pri_shift,
+ 0,
+ 0,
+ 0);
- assert_wait_deadline((event_t)sched_tick_thread, THREAD_UNINT, sched_tick_deadline);
- thread_block((thread_continue_t)sched_tick_continue);
+ assert_wait((event_t)sched_traditional_maintenance_continue, THREAD_UNINT);
+ thread_block((thread_continue_t)sched_traditional_maintenance_continue);
/*NOTREACHED*/
}
+static uint64_t sched_maintenance_wakeups;
+
/*
- * Time a series of context switches to determine
- * a baseline. Toss the high and low and return
- * the one-way value.
+ * Determine if the set of routines formerly driven by a maintenance timer
+ * must be invoked, based on a deadline comparison. Signals the scheduler
+ * maintenance thread on deadline expiration. Must be invoked at an interval
+ * lower than the "sched_tick_interval", currently accomplished by
+ * invocation via the quantum expiration timer and at context switch time.
+ * Performance matters: this routine reuses a timestamp approximating the
+ * current absolute time received from the caller, and should perform
+ * no more than a comparison against the deadline in the common case.
*/
-static uint32_t
-time_cswitch(void)
-{
- uint32_t new, hi, low, accum;
- uint64_t abstime;
- int i, tries = 7;
+void
+sched_traditional_consider_maintenance(uint64_t ctime) {
+ uint64_t ndeadline, deadline = sched_maintenance_deadline;
- accum = hi = low = 0;
- for (i = 0; i < tries; ++i) {
- abstime = mach_absolute_time();
- thread_block(THREAD_CONTINUE_NULL);
+ if (__improbable(ctime >= deadline)) {
+ if (__improbable(current_thread() == sched_maintenance_thread))
+ return;
+ OSMemoryBarrier();
- new = mach_absolute_time() - abstime;
+ ndeadline = ctime + sched_tick_interval;
- if (i == 0)
- accum = hi = low = new;
- else {
- if (new < low)
- low = new;
- else
- if (new > hi)
- hi = new;
- accum += new;
+ if (__probable(__sync_bool_compare_and_swap(&sched_maintenance_deadline, deadline, ndeadline))) {
+ thread_wakeup((event_t)sched_traditional_maintenance_continue);
+ sched_maintenance_wakeups++;
}
}
- return ((accum - hi - low) / (2 * (tries - 2)));
+#if defined(CONFIG_TELEMETRY)
+ /*
+ * Windowed telemetry is driven by the scheduler. It should be safe
+ * to call compute_telemetry_windowed() even when windowed telemetry
+ * is disabled, but we should try to avoid doing extra work for no
+ * reason.
+ */
+ if (telemetry_window_enabled) {
+ deadline = sched_telemetry_deadline;
+
+ if (__improbable(ctime >= deadline)) {
+ ndeadline = ctime + sched_telemetry_interval;
+
+ if (__probable(__sync_bool_compare_and_swap(&sched_telemetry_deadline, deadline, ndeadline))) {
+ compute_telemetry_windowed();
+ }
+ }
+ }
+#endif /* CONFIG_TELEMETRY */
}
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
void
-sched_tick_thread(void)
+sched_init_thread(void (*continuation)(void))
{
- sched_cswtime = time_cswitch();
+ thread_block(THREAD_CONTINUE_NULL);
- sched_tick_deadline = mach_absolute_time();
+ sched_maintenance_thread = current_thread();
+ continuation();
- sched_tick_continue();
/*NOTREACHED*/
}
+#if defined(CONFIG_SCHED_TIMESHARE_CORE)
+
/*
* thread_update_scan / runq_scan:
*
static thread_t thread_update_array[THREAD_UPDATE_SIZE];
static int thread_update_count = 0;
+/* Returns TRUE if thread was added, FALSE if thread_update_array is full */
+boolean_t
+thread_update_add_thread(thread_t thread)
+{
+ if (thread_update_count == THREAD_UPDATE_SIZE)
+ return (FALSE);
+
+ thread_update_array[thread_update_count++] = thread;
+ thread_reference_internal(thread);
+ return (TRUE);
+}
+
+void
+thread_update_process_threads(void)
+{
+ while (thread_update_count > 0) {
+ spl_t s;
+ thread_t thread = thread_update_array[--thread_update_count];
+ thread_update_array[thread_update_count] = THREAD_NULL;
+
+ s = splsched();
+ thread_lock(thread);
+ if (!(thread->state & (TH_WAIT)) && (SCHED(can_update_priority)(thread))) {
+ SCHED(update_priority)(thread);
+ }
+ thread_unlock(thread);
+ splx(s);
+
+ thread_deallocate(thread);
+ }
+}
+
/*
* Scan a runq for candidate threads.
*
* Returns TRUE if retry is needed.
*/
-static boolean_t
+boolean_t
runq_scan(
run_queue_t runq)
{
while (count > 0) {
queue_iterate(q, thread, thread_t, links) {
if ( thread->sched_stamp != sched_tick &&
- (thread->sched_mode & TH_MODE_TIMESHARE) ) {
- if (thread_update_count == THREAD_UPDATE_SIZE)
+ (thread->sched_mode == TH_MODE_TIMESHARE) ) {
+ if (thread_update_add_thread(thread) == FALSE)
return (TRUE);
-
- thread_update_array[thread_update_count++] = thread;
- thread_reference_internal(thread);
}
count--;
return (FALSE);
}
+#endif /* CONFIG_SCHED_TIMESHARE_CORE */
+
+#if defined(CONFIG_SCHED_TRADITIONAL)
+
static void
thread_update_scan(void)
{
- register boolean_t restart_needed;
- register processor_set_t pset = &default_pset;
- register processor_t processor;
- register thread_t thread;
- spl_t s;
+ boolean_t restart_needed = FALSE;
+ processor_t processor = processor_list;
+ processor_set_t pset;
+ thread_t thread;
+ spl_t s;
do {
- s = splsched();
- simple_lock(&pset->sched_lock);
- restart_needed = runq_scan(&pset->runq);
- simple_unlock(&pset->sched_lock);
-
- if (!restart_needed) {
- simple_lock(&pset->sched_lock);
- processor = (processor_t)queue_first(&pset->processors);
- while (!queue_end(&pset->processors, (queue_entry_t)processor)) {
- if ((restart_needed = runq_scan(&processor->runq)) != 0)
- break;
+ do {
+ /*
+ * TODO: in sched_traditional_use_pset_runqueue case,
+ * avoid scanning the same runq multiple times
+ */
+ pset = processor->processor_set;
- thread = processor->idle_thread;
- if (thread->sched_stamp != sched_tick) {
- if (thread_update_count == THREAD_UPDATE_SIZE) {
- restart_needed = TRUE;
- break;
- }
+ s = splsched();
+ pset_lock(pset);
- thread_update_array[thread_update_count++] = thread;
- thread_reference_internal(thread);
- }
+ restart_needed = runq_scan(runq_for_processor(processor));
- processor = (processor_t)queue_next(&processor->processors);
- }
- simple_unlock(&pset->sched_lock);
- }
- splx(s);
+ pset_unlock(pset);
+ splx(s);
- /*
- * Ok, we now have a collection of candidates -- fix them.
- */
- while (thread_update_count > 0) {
- thread = thread_update_array[--thread_update_count];
- thread_update_array[thread_update_count] = THREAD_NULL;
+ if (restart_needed)
+ break;
- s = splsched();
- thread_lock(thread);
- if ( !(thread->state & (TH_WAIT|TH_SUSP)) &&
- thread->sched_stamp != sched_tick )
- update_priority(thread);
- thread_unlock(thread);
- splx(s);
+ thread = processor->idle_thread;
+ if (thread != THREAD_NULL && thread->sched_stamp != sched_tick) {
+ if (thread_update_add_thread(thread) == FALSE) {
+ restart_needed = TRUE;
+ break;
+ }
+ }
+ } while ((processor = processor->processor_list) != NULL);
- thread_deallocate(thread);
- }
+ /* Ok, we now have a collection of candidates -- fix them. */
+ thread_update_process_threads();
} while (restart_needed);
}
+
+#endif /* CONFIG_SCHED_TRADITIONAL */
+
+boolean_t
+thread_eager_preemption(thread_t thread)
+{
+ return ((thread->sched_flags & TH_SFLAG_EAGERPREEMPT) != 0);
+}
+
+void
+thread_set_eager_preempt(thread_t thread)
+{
+ spl_t x;
+ processor_t p;
+ ast_t ast = AST_NONE;
+
+ x = splsched();
+ p = current_processor();
+
+ thread_lock(thread);
+ thread->sched_flags |= TH_SFLAG_EAGERPREEMPT;
+
+ if (thread == current_thread()) {
+
+ ast = csw_check(p, AST_NONE);
+ thread_unlock(thread);
+ if (ast != AST_NONE) {
+ (void) thread_block_reason(THREAD_CONTINUE_NULL, NULL, ast);
+ }
+ } else {
+ p = thread->last_processor;
+
+ if (p != PROCESSOR_NULL && p->state == PROCESSOR_RUNNING &&
+ p->active_thread == thread) {
+ cause_ast_check(p);
+ }
+ thread_unlock(thread);
+ }
+
+ splx(x);
+}
+
+void
+thread_clear_eager_preempt(thread_t thread)
+{
+ spl_t x;
+
+ x = splsched();
+ thread_lock(thread);
+
+ thread->sched_flags &= ~TH_SFLAG_EAGERPREEMPT;
+
+ thread_unlock(thread);
+ splx(x);
+}
+/*
+ * Scheduling statistics
+ */
+void
+sched_stats_handle_csw(processor_t processor, int reasons, int selfpri, int otherpri)
+{
+ struct processor_sched_statistics *stats;
+ boolean_t to_realtime = FALSE;
+
+ stats = &processor->processor_data.sched_stats;
+ stats->csw_count++;
+
+ if (otherpri >= BASEPRI_REALTIME) {
+ stats->rt_sched_count++;
+ to_realtime = TRUE;
+ }
+
+ if ((reasons & AST_PREEMPT) != 0) {
+ stats->preempt_count++;
+
+ if (selfpri >= BASEPRI_REALTIME) {
+ stats->preempted_rt_count++;
+ }
+
+ if (to_realtime) {
+ stats->preempted_by_rt_count++;
+ }
+
+ }
+}
+
+void
+sched_stats_handle_runq_change(struct runq_stats *stats, int old_count)
+{
+ uint64_t timestamp = mach_absolute_time();
+
+ stats->count_sum += (timestamp - stats->last_change_timestamp) * old_count;
+ stats->last_change_timestamp = timestamp;
+}
+
/*
- * Just in case someone doesn't use the macro
+ * For calls from assembly code
*/
-#undef thread_wakeup
+#undef thread_wakeup
void
thread_wakeup(
- event_t x);
+ event_t x);
void
thread_wakeup(
- event_t x)
+ event_t x)
{
- thread_wakeup_with_result(x, THREAD_AWAKENED);
+ thread_wakeup_with_result(x, THREAD_AWAKENED);
}
boolean_t
return (get_preemption_level() == 0 && ml_get_interrupts_enabled());
}
-#if DEBUG
-static boolean_t
+__assert_only static boolean_t
thread_runnable(
thread_t thread)
{
return ((thread->state & (TH_RUN|TH_WAIT)) == TH_RUN);
}
-#endif /* DEBUG */
-
-#if MACH_KDB
-#include <ddb/db_output.h>
-#define printf kdbprintf
-void db_sched(void);
-
-void
-db_sched(void)
-{
- iprintf("Scheduling Statistics:\n");
- db_indent += 2;
- iprintf("Thread invocations: csw %d same %d\n",
- c_thread_invoke_csw, c_thread_invoke_same);
-#if MACH_COUNTERS
- iprintf("Thread block: calls %d\n",
- c_thread_block_calls);
- iprintf("Idle thread:\n\thandoff %d block %d no_dispatch %d\n",
- c_idle_thread_handoff,
- c_idle_thread_block, no_dispatch_count);
- iprintf("Sched thread blocks: %d\n", c_sched_thread_block);
-#endif /* MACH_COUNTERS */
- db_indent -= 2;
-}
-
-#include <ddb/db_output.h>
-void db_show_thread_log(void);
-void
-db_show_thread_log(void)
-{
+static void
+sched_timer_deadline_tracking_init(void) {
+ nanoseconds_to_absolutetime(TIMER_DEADLINE_TRACKING_BIN_1_DEFAULT, &timer_deadline_tracking_bin_1);
+ nanoseconds_to_absolutetime(TIMER_DEADLINE_TRACKING_BIN_2_DEFAULT, &timer_deadline_tracking_bin_2);
}
-#endif /* MACH_KDB */
projects / apple / xnu.git / blobdiff