/*
- * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2010 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
/*
* @OSF_COPYRIGHT@
*/
-/*
- * 8/13/93
- *
- * This is a half-hearted attempt at providing the parts of the
- * ledger facility to satisfy the ledger interfaces.
- *
- * This implementation basically leaves the (dysfunctional) ledgers
- * unfunctional and are mearly here to satisfy the Mach spec interface
- * reqirements.
- */
-#include <mach/mach_types.h>
-#include <mach/message.h>
-#include <mach/port.h>
-#include <mach/ledger_server.h>
-
-#include <kern/mach_param.h>
-#include <kern/misc_protos.h>
-#include <kern/lock.h>
-#include <kern/ipc_kobject.h>
-#include <kern/host.h>
+#include <kern/kern_types.h>
#include <kern/ledger.h>
#include <kern/kalloc.h>
+#include <kern/task.h>
+
+#include <kern/processor.h>
+#include <kern/machine.h>
+#include <kern/queue.h>
+#include <sys/errno.h>
+
+#include <libkern/OSAtomic.h>
+#include <mach/mach_types.h>
-#include <ipc/ipc_space.h>
-#include <ipc/ipc_port.h>
+/*
+ * Ledger entry flags. Bits in second nibble (masked by 0xF0) are used for
+ * ledger actions (LEDGER_ACTION_BLOCK, etc).
+ */
+#define LF_ENTRY_ACTIVE 0x0001 /* entry is active if set */
+#define LF_WAKE_NEEDED 0x0100 /* one or more threads are asleep */
+#define LF_WAKE_INPROGRESS 0x0200 /* the wait queue is being processed */
+#define LF_REFILL_SCHEDULED 0x0400 /* a refill timer has been set */
+#define LF_REFILL_INPROGRESS 0x0800 /* the ledger is being refilled */
+#define LF_CALLED_BACK 0x1000 /* callback was called for balance in deficit */
+#define LF_WARNED 0x2000 /* callback was called for balance warning */
+#define LF_TRACKING_MAX 0x4000 /* track max balance over user-specfied time */
+#define LF_PANIC_ON_NEGATIVE 0x8000 /* panic if it goes negative */
-ledger_t root_wired_ledger;
-ledger_t root_paged_ledger;
+/* Determine whether a ledger entry exists and has been initialized and active */
+#define ENTRY_VALID(l, e) \
+ (((l) != NULL) && ((e) >= 0) && ((e) < (l)->l_size) && \
+ (((l)->l_entries[e].le_flags & LF_ENTRY_ACTIVE) == LF_ENTRY_ACTIVE))
+#define ASSERT(a) assert(a)
-/* Utility routine to handle entries to a ledger */
-kern_return_t
-ledger_enter(
- ledger_t ledger,
- ledger_item_t amount)
+#ifdef LEDGER_DEBUG
+int ledger_debug = 0;
+
+#define lprintf(a) if (ledger_debug) { \
+ printf("%lld ", abstime_to_nsecs(mach_absolute_time() / 1000000)); \
+ printf a ; \
+}
+#else
+#define lprintf(a)
+#endif
+
+struct ledger_callback {
+ ledger_callback_t lc_func;
+ const void *lc_param0;
+ const void *lc_param1;
+};
+
+struct entry_template {
+ char et_key[LEDGER_NAME_MAX];
+ char et_group[LEDGER_NAME_MAX];
+ char et_units[LEDGER_NAME_MAX];
+ uint32_t et_flags;
+ struct ledger_callback *et_callback;
+};
+
+lck_grp_t ledger_lck_grp;
+
+/*
+ * Modifying the reference count, table size, or table contents requires
+ * holding the lt_lock. Modfying the table address requires both lt_lock
+ * and setting the inuse bit. This means that the lt_entries field can be
+ * safely dereferenced if you hold either the lock or the inuse bit. The
+ * inuse bit exists solely to allow us to swap in a new, larger entries
+ * table without requiring a full lock to be acquired on each lookup.
+ * Accordingly, the inuse bit should never be held for longer than it takes
+ * to extract a value from the table - i.e., 2 or 3 memory references.
+ */
+struct ledger_template {
+ const char *lt_name;
+ int lt_refs;
+ int lt_cnt;
+ int lt_table_size;
+ volatile uint32_t lt_inuse;
+ lck_mtx_t lt_lock;
+ struct entry_template *lt_entries;
+};
+
+#define template_lock(template) lck_mtx_lock(&(template)->lt_lock)
+#define template_unlock(template) lck_mtx_unlock(&(template)->lt_lock)
+
+#define TEMPLATE_INUSE(s, t) { \
+ s = splsched(); \
+ while (OSCompareAndSwap(0, 1, &((t)->lt_inuse))) \
+ ; \
+}
+
+#define TEMPLATE_IDLE(s, t) { \
+ (t)->lt_inuse = 0; \
+ splx(s); \
+}
+
+/*
+ * Use 2 "tocks" to track the rolling maximum balance of a ledger entry.
+ */
+#define NTOCKS 2
+/*
+ * The explicit alignment is to ensure that atomic operations don't panic
+ * on ARM.
+ */
+struct ledger_entry {
+ volatile uint32_t le_flags;
+ ledger_amount_t le_limit;
+ ledger_amount_t le_warn_level;
+ volatile ledger_amount_t le_credit __attribute__((aligned(8)));
+ volatile ledger_amount_t le_debit __attribute__((aligned(8)));
+ union {
+ struct {
+ /*
+ * XXX - the following two fields can go away if we move all of
+ * the refill logic into process policy
+ */
+ uint64_t le_refill_period;
+ uint64_t le_last_refill;
+ } le_refill;
+ struct _le_peak {
+ uint32_t le_max; /* Lower 32-bits of observed max balance */
+ uint32_t le_time; /* time when this peak was observed */
+ } le_peaks[NTOCKS];
+ } _le;
+} __attribute__((aligned(8)));
+
+struct ledger {
+ int l_id;
+ struct ledger_template *l_template;
+ int l_refs;
+ int l_size;
+ struct ledger_entry *l_entries;
+};
+
+static int ledger_cnt = 0;
+/* ledger ast helper functions */
+static uint32_t ledger_check_needblock(ledger_t l, uint64_t now);
+static kern_return_t ledger_perform_blocking(ledger_t l);
+static uint32_t flag_set(volatile uint32_t *flags, uint32_t bit);
+static uint32_t flag_clear(volatile uint32_t *flags, uint32_t bit);
+
+#if 0
+static void
+debug_callback(const void *p0, __unused const void *p1)
{
- /* Need to lock the ledger */
- ledger_lock(ledger);
-
- if (amount > 0) {
- if (ledger->ledger_limit != LEDGER_ITEM_INFINITY &&
- ledger->ledger_balance + amount > ledger->ledger_limit) {
- /* XXX this is where you do BAD things */
- printf("Ledger limit exceeded ! ledger=%p lim=%d balance=%d\n",
- ledger, ledger->ledger_limit,
- ledger->ledger_balance);
- ledger_unlock(ledger);
- return(KERN_RESOURCE_SHORTAGE);
+ printf("ledger: resource exhausted [%s] for task %p\n",
+ (const char *)p0, p1);
+}
+#endif
+
+/************************************/
+
+static uint64_t
+abstime_to_nsecs(uint64_t abstime)
+{
+ uint64_t nsecs;
+
+ absolutetime_to_nanoseconds(abstime, &nsecs);
+ return (nsecs);
+}
+
+static uint64_t
+nsecs_to_abstime(uint64_t nsecs)
+{
+ uint64_t abstime;
+
+ nanoseconds_to_absolutetime(nsecs, &abstime);
+ return (abstime);
+}
+
+void
+ledger_init(void)
+{
+ lck_grp_init(&ledger_lck_grp, "ledger", LCK_GRP_ATTR_NULL);
+}
+
+ledger_template_t
+ledger_template_create(const char *name)
+{
+ ledger_template_t template;
+
+ template = (ledger_template_t)kalloc(sizeof (*template));
+ if (template == NULL)
+ return (NULL);
+
+ template->lt_name = name;
+ template->lt_refs = 1;
+ template->lt_cnt = 0;
+ template->lt_table_size = 1;
+ template->lt_inuse = 0;
+ lck_mtx_init(&template->lt_lock, &ledger_lck_grp, LCK_ATTR_NULL);
+
+ template->lt_entries = (struct entry_template *)
+ kalloc(sizeof (struct entry_template) * template->lt_table_size);
+ if (template->lt_entries == NULL) {
+ kfree(template, sizeof (*template));
+ template = NULL;
+ }
+
+ return (template);
+}
+
+void
+ledger_template_dereference(ledger_template_t template)
+{
+ template_lock(template);
+ template->lt_refs--;
+ template_unlock(template);
+
+ if (template->lt_refs == 0)
+ kfree(template, sizeof (*template));
+}
+
+/*
+ * Add a new entry to the list of entries in a ledger template. There is
+ * currently no mechanism to remove an entry. Implementing such a mechanism
+ * would require us to maintain per-entry reference counts, which we would
+ * prefer to avoid if possible.
+ */
+int
+ledger_entry_add(ledger_template_t template, const char *key,
+ const char *group, const char *units)
+{
+ int idx;
+ struct entry_template *et;
+
+ if ((key == NULL) || (strlen(key) >= LEDGER_NAME_MAX))
+ return (-1);
+
+ template_lock(template);
+
+ /* If the table is full, attempt to double its size */
+ if (template->lt_cnt == template->lt_table_size) {
+ struct entry_template *new_entries, *old_entries;
+ int old_cnt, old_sz;
+ spl_t s;
+
+ old_cnt = template->lt_table_size;
+ old_sz = (int)(old_cnt * sizeof (struct entry_template));
+ new_entries = kalloc(old_sz * 2);
+ if (new_entries == NULL) {
+ template_unlock(template);
+ return (-1);
}
- if ((ledger->ledger_balance + amount)
- < LEDGER_ITEM_INFINITY)
- ledger->ledger_balance += amount;
- else
- ledger->ledger_balance = LEDGER_ITEM_INFINITY;
- }
- else if (amount) {
- if (ledger->ledger_balance + amount > 0)
- ledger->ledger_balance += amount;
- else
- ledger->ledger_balance = 0;
- }
- ledger_unlock(ledger);
- return(KERN_SUCCESS);
+ memcpy(new_entries, template->lt_entries, old_sz);
+ memset(((char *)new_entries) + old_sz, 0, old_sz);
+ template->lt_table_size = old_cnt * 2;
+
+ old_entries = template->lt_entries;
+
+ TEMPLATE_INUSE(s, template);
+ template->lt_entries = new_entries;
+ TEMPLATE_IDLE(s, template);
+
+ kfree(old_entries, old_sz);
+ }
+
+ et = &template->lt_entries[template->lt_cnt];
+ strlcpy(et->et_key, key, LEDGER_NAME_MAX);
+ strlcpy(et->et_group, group, LEDGER_NAME_MAX);
+ strlcpy(et->et_units, units, LEDGER_NAME_MAX);
+ et->et_flags = LF_ENTRY_ACTIVE;
+ et->et_callback = NULL;
+
+ idx = template->lt_cnt++;
+ template_unlock(template);
+
+ return (idx);
}
-/* Utility routine to create a new ledger */
-static ledger_t
-ledger_allocate(
- ledger_item_t limit,
- ledger_t ledger_ledger,
- ledger_t ledger_parent)
+
+kern_return_t
+ledger_entry_setactive(ledger_t ledger, int entry)
{
- ledger_t ledger;
+ struct ledger_entry *le;
- ledger = (ledger_t)kalloc(sizeof(ledger_data_t));
- if (ledger == LEDGER_NULL)
- return(LEDGER_NULL);
+ if ((ledger == NULL) || (entry < 0) || (entry >= ledger->l_size))
+ return (KERN_INVALID_ARGUMENT);
- ledger->ledger_self = ipc_port_alloc_kernel();
- if (ledger->ledger_self == IP_NULL) {
- kfree(ledger, sizeof(ledger_data_t));
- return(LEDGER_NULL);
+ le = &ledger->l_entries[entry];
+ if ((le->le_flags & LF_ENTRY_ACTIVE) == 0) {
+ flag_set(&le->le_flags, LF_ENTRY_ACTIVE);
}
+ return (KERN_SUCCESS);
+}
+
+
+int
+ledger_key_lookup(ledger_template_t template, const char *key)
+{
+ int idx;
- ledger_lock_init(ledger);
- ledger->ledger_limit = limit;
- ledger->ledger_balance = 0;
- ledger->ledger_service_port = MACH_PORT_NULL;
- ledger->ledger_ledger = ledger_ledger;
- ledger->ledger_parent = ledger_parent;
- ipc_kobject_set(ledger->ledger_self, (ipc_kobject_t)ledger,
- IKOT_LEDGER);
+ template_lock(template);
+ for (idx = 0; idx < template->lt_cnt; idx++)
+ if (template->lt_entries[idx].et_key &&
+ (strcmp(key, template->lt_entries[idx].et_key) == 0))
+ break;
- return(ledger);
+ if (idx >= template->lt_cnt)
+ idx = -1;
+ template_unlock(template);
+
+ return (idx);
}
-/* Utility routine to destroy a ledger */
-static void
-ledger_deallocate(
- ledger_t ledger)
+/*
+ * Create a new ledger based on the specified template. As part of the
+ * ledger creation we need to allocate space for a table of ledger entries.
+ * The size of the table is based on the size of the template at the time
+ * the ledger is created. If additional entries are added to the template
+ * after the ledger is created, they will not be tracked in this ledger.
+ */
+ledger_t
+ledger_instantiate(ledger_template_t template, int entry_type)
{
- /* XXX can be many send rights (copies) of this */
- ipc_port_dealloc_kernel(ledger->ledger_self);
+ ledger_t ledger;
+ size_t sz;
+ int i;
+
+ ledger = (ledger_t)kalloc(sizeof (struct ledger));
+ if (ledger == NULL)
+ return (LEDGER_NULL);
+
+ ledger->l_template = template;
+ ledger->l_id = ledger_cnt++;
+ ledger->l_refs = 1;
+
+ template_lock(template);
+ template->lt_refs++;
+ ledger->l_size = template->lt_cnt;
+ template_unlock(template);
+
+ sz = ledger->l_size * sizeof (struct ledger_entry);
+ ledger->l_entries = kalloc(sz);
+ if (sz && (ledger->l_entries == NULL)) {
+ ledger_template_dereference(template);
+ kfree(ledger, sizeof(struct ledger));
+ return (LEDGER_NULL);
+ }
+
+ template_lock(template);
+ assert(ledger->l_size <= template->lt_cnt);
+ for (i = 0; i < ledger->l_size; i++) {
+ struct ledger_entry *le = &ledger->l_entries[i];
+ struct entry_template *et = &template->lt_entries[i];
- /* XXX release send right on service port */
- kfree(ledger, sizeof(*ledger));
+ le->le_flags = et->et_flags;
+ /* make entry inactive by removing active bit */
+ if (entry_type == LEDGER_CREATE_INACTIVE_ENTRIES)
+ flag_clear(&le->le_flags, LF_ENTRY_ACTIVE);
+ /*
+ * If template has a callback, this entry is opted-in,
+ * by default.
+ */
+ if (et->et_callback != NULL)
+ flag_set(&le->le_flags, LEDGER_ACTION_CALLBACK);
+ le->le_credit = 0;
+ le->le_debit = 0;
+ le->le_limit = LEDGER_LIMIT_INFINITY;
+ le->le_warn_level = LEDGER_LIMIT_INFINITY;
+ le->_le.le_refill.le_refill_period = 0;
+ le->_le.le_refill.le_last_refill = 0;
+ }
+ template_unlock(template);
+
+ return (ledger);
+}
+
+static uint32_t
+flag_set(volatile uint32_t *flags, uint32_t bit)
+{
+ return (OSBitOrAtomic(bit, flags));
+}
+
+static uint32_t
+flag_clear(volatile uint32_t *flags, uint32_t bit)
+{
+ return (OSBitAndAtomic(~bit, flags));
+}
+
+/*
+ * Take a reference on a ledger
+ */
+kern_return_t
+ledger_reference(ledger_t ledger)
+{
+ if (!LEDGER_VALID(ledger))
+ return (KERN_INVALID_ARGUMENT);
+ OSIncrementAtomic(&ledger->l_refs);
+ return (KERN_SUCCESS);
+}
+
+int
+ledger_reference_count(ledger_t ledger)
+{
+ if (!LEDGER_VALID(ledger))
+ return (-1);
+
+ return (ledger->l_refs);
}
+/*
+ * Remove a reference on a ledger. If this is the last reference,
+ * deallocate the unused ledger.
+ */
+kern_return_t
+ledger_dereference(ledger_t ledger)
+{
+ int v;
+
+ if (!LEDGER_VALID(ledger))
+ return (KERN_INVALID_ARGUMENT);
+
+ v = OSDecrementAtomic(&ledger->l_refs);
+ ASSERT(v >= 1);
+
+ /* Just released the last reference. Free it. */
+ if (v == 1) {
+ kfree(ledger->l_entries,
+ ledger->l_size * sizeof (struct ledger_entry));
+ kfree(ledger, sizeof (*ledger));
+ }
+
+ return (KERN_SUCCESS);
+}
/*
- * Inititalize the ledger facility
+ * Determine whether an entry has exceeded its warning level.
*/
-void ledger_init(void)
+static inline int
+warn_level_exceeded(struct ledger_entry *le)
{
+ ledger_amount_t balance;
+
+ assert((le->le_credit >= 0) && (le->le_debit >= 0));
+
/*
- * Allocate the root ledgers; wired and paged.
+ * XXX - Currently, we only support warnings for ledgers which
+ * use positive limits.
*/
- root_wired_ledger = ledger_allocate(LEDGER_ITEM_INFINITY,
- LEDGER_NULL, LEDGER_NULL);
- if (root_wired_ledger == LEDGER_NULL)
- panic("can't allocate root (wired) ledger");
- ipc_port_make_send(root_wired_ledger->ledger_self);
+ balance = le->le_credit - le->le_debit;
+ if ((le->le_warn_level != LEDGER_LIMIT_INFINITY) && (balance > le->le_warn_level))
+ return (1);
+ return (0);
+}
+
+/*
+ * Determine whether an entry has exceeded its limit.
+ */
+static inline int
+limit_exceeded(struct ledger_entry *le)
+{
+ ledger_amount_t balance;
+
+ assert((le->le_credit >= 0) && (le->le_debit >= 0));
+
+ balance = le->le_credit - le->le_debit;
+ if ((le->le_limit <= 0) && (balance < le->le_limit))
+ return (1);
+
+ if ((le->le_limit > 0) && (balance > le->le_limit))
+ return (1);
+ return (0);
+}
+
+static inline struct ledger_callback *
+entry_get_callback(ledger_t ledger, int entry)
+{
+ struct ledger_callback *callback;
+ spl_t s;
+
+ TEMPLATE_INUSE(s, ledger->l_template);
+ callback = ledger->l_template->lt_entries[entry].et_callback;
+ TEMPLATE_IDLE(s, ledger->l_template);
- root_paged_ledger = ledger_allocate(LEDGER_ITEM_INFINITY,
- LEDGER_NULL, LEDGER_NULL);
- if (root_paged_ledger == LEDGER_NULL)
- panic("can't allocate root (paged) ledger");
- ipc_port_make_send(root_paged_ledger->ledger_self);
+ return (callback);
}
/*
- * Create a subordinate ledger
+ * If the ledger value is positive, wake up anybody waiting on it.
*/
-kern_return_t ledger_create(
- ledger_t parent_ledger,
- ledger_t ledger_ledger,
- ledger_t *new_ledger,
- ledger_item_t transfer)
+static inline void
+ledger_limit_entry_wakeup(struct ledger_entry *le)
{
- if (parent_ledger == LEDGER_NULL)
- return(KERN_INVALID_ARGUMENT);
+ uint32_t flags;
- if (ledger_ledger == LEDGER_NULL)
- return(KERN_INVALID_LEDGER);
+ if (!limit_exceeded(le)) {
+ flags = flag_clear(&le->le_flags, LF_CALLED_BACK);
+
+ while (le->le_flags & LF_WAKE_NEEDED) {
+ flag_clear(&le->le_flags, LF_WAKE_NEEDED);
+ thread_wakeup((event_t)le);
+ }
+ }
+}
+
+/*
+ * Refill the coffers.
+ */
+static void
+ledger_refill(uint64_t now, ledger_t ledger, int entry)
+{
+ uint64_t elapsed, period, periods;
+ struct ledger_entry *le;
+ ledger_amount_t balance, due;
+
+ le = &ledger->l_entries[entry];
+
+ assert(le->le_limit != LEDGER_LIMIT_INFINITY);
/*
- * Allocate a new ledger and change the ledger_ledger for
- * its space.
+ * If another thread is handling the refill already, we're not
+ * needed.
*/
- ledger_lock(ledger_ledger);
- if ((ledger_ledger->ledger_limit != LEDGER_ITEM_INFINITY) &&
- (ledger_ledger->ledger_balance + sizeof(ledger_data_t) >
- ledger_ledger->ledger_limit)) {
- ledger_unlock(ledger_ledger);
- return(KERN_RESOURCE_SHORTAGE);
+ if (flag_set(&le->le_flags, LF_REFILL_INPROGRESS) & LF_REFILL_INPROGRESS) {
+ return;
}
- *new_ledger = ledger_allocate(LEDGER_ITEM_INFINITY, ledger_ledger, parent_ledger);
- if (*new_ledger == LEDGER_NULL) {
- ledger_unlock(ledger_ledger);
- return(KERN_RESOURCE_SHORTAGE);
+ /*
+ * If the timestamp we're about to use to refill is older than the
+ * last refill, then someone else has already refilled this ledger
+ * and there's nothing for us to do here.
+ */
+ if (now <= le->_le.le_refill.le_last_refill) {
+ flag_clear(&le->le_flags, LF_REFILL_INPROGRESS);
+ return;
}
-
+
/*
- * Now transfer the limit for the new ledger from the parent
+ * See how many refill periods have passed since we last
+ * did a refill.
*/
- ledger_lock(parent_ledger);
- if (parent_ledger->ledger_limit != LEDGER_ITEM_INFINITY) {
- /* Would the existing balance exceed the new limit ? */
- if (parent_ledger->ledger_limit - transfer < parent_ledger->ledger_balance) {
- ledger_unlock(parent_ledger);
- ledger_unlock(ledger_ledger);
- return(KERN_RESOURCE_SHORTAGE);
- }
- if (parent_ledger->ledger_limit - transfer > 0)
- parent_ledger->ledger_limit -= transfer;
- else
- parent_ledger->ledger_limit = 0;
+ period = le->_le.le_refill.le_refill_period;
+ elapsed = now - le->_le.le_refill.le_last_refill;
+ if ((period == 0) || (elapsed < period)) {
+ flag_clear(&le->le_flags, LF_REFILL_INPROGRESS);
+ return;
}
- (*new_ledger)->ledger_limit = transfer;
- /* Charge the ledger against the ledger_ledger */
- ledger_ledger->ledger_balance += sizeof(ledger_data_t);
- ledger_unlock(parent_ledger);
+ /*
+ * Optimize for the most common case of only one or two
+ * periods elapsing.
+ */
+ periods = 0;
+ while ((periods < 2) && (elapsed > 0)) {
+ periods++;
+ elapsed -= period;
+ }
- ledger_unlock(ledger_ledger);
-
- return(KERN_SUCCESS);
+ /*
+ * OK, it's been a long time. Do a divide to figure out
+ * how long.
+ */
+ if (elapsed > 0)
+ periods = (now - le->_le.le_refill.le_last_refill) / period;
+
+ balance = le->le_credit - le->le_debit;
+ due = periods * le->le_limit;
+ if (balance - due < 0)
+ due = balance;
+
+ assert(due >= 0);
+
+ OSAddAtomic64(due, &le->le_debit);
+
+ assert(le->le_debit >= 0);
+
+ /*
+ * If we've completely refilled the pool, set the refill time to now.
+ * Otherwise set it to the time at which it last should have been
+ * fully refilled.
+ */
+ if (balance == due)
+ le->_le.le_refill.le_last_refill = now;
+ else
+ le->_le.le_refill.le_last_refill += (le->_le.le_refill.le_refill_period * periods);
+
+ flag_clear(&le->le_flags, LF_REFILL_INPROGRESS);
+
+ lprintf(("Refill %lld %lld->%lld\n", periods, balance, balance - due));
+ if (!limit_exceeded(le))
+ ledger_limit_entry_wakeup(le);
}
/*
- * Destroy a ledger
+ * In tenths of a second, the length of one lookback period (a "tock") for
+ * ledger rolling maximum calculations. The effective lookback window will be this times
+ * NTOCKS.
+ *
+ * Use a tock length of 2.5 seconds to get a total lookback period of 5 seconds.
+ *
+ * XXX Could make this caller-definable, at the point that rolling max tracking
+ * is enabled for the entry.
+ */
+#define TOCKLEN 25
+
+/*
+ * How many sched_tick's are there in one tock (one of our lookback periods)?
+ *
+ * X sched_ticks 2.5 sec N sched_ticks
+ * --------------- = ---------- * -------------
+ * tock tock sec
+ *
+ * where N sched_ticks/sec is calculated via 1 << SCHED_TICK_SHIFT (see sched_prim.h)
+ *
+ * This should give us 20 sched_tick's in one 2.5 second-long tock.
*/
-kern_return_t ledger_terminate(
- ledger_t ledger)
+#define SCHED_TICKS_PER_TOCK ((TOCKLEN * (1 << SCHED_TICK_SHIFT)) / 10)
+
+/*
+ * Rolling max timestamps use their own unit (let's call this a "tock"). One tock is the
+ * length of one lookback period that we use for our rolling max calculation.
+ *
+ * Calculate the current time in tocks from sched_tick (which runs at a some
+ * fixed rate).
+ */
+#define CURRENT_TOCKSTAMP() (sched_tick / SCHED_TICKS_PER_TOCK)
+
+/*
+ * Does the given tockstamp fall in either the current or the previous tocks?
+ */
+#define TOCKSTAMP_IS_STALE(now, tock) ((((now) - (tock)) < NTOCKS) ? FALSE : TRUE)
+
+static void
+ledger_check_new_balance(ledger_t ledger, int entry)
{
- if (ledger == LEDGER_NULL)
- return(KERN_INVALID_ARGUMENT);
-
- /* You can't deallocate kernel ledgers */
- if (ledger == root_wired_ledger ||
- ledger == root_paged_ledger)
- return(KERN_INVALID_LEDGER);
+ struct ledger_entry *le;
- /* Lock the ledger */
- ledger_lock(ledger);
-
- /* the parent ledger gets back the limit */
- ledger_lock(ledger->ledger_parent);
- if (ledger->ledger_parent->ledger_limit != LEDGER_ITEM_INFINITY) {
- assert((natural_t)(ledger->ledger_parent->ledger_limit +
- ledger->ledger_limit) <
- LEDGER_ITEM_INFINITY);
- ledger->ledger_parent->ledger_limit += ledger->ledger_limit;
+ le = &ledger->l_entries[entry];
+
+ if (le->le_flags & LF_TRACKING_MAX) {
+ ledger_amount_t balance = le->le_credit - le->le_debit;
+ uint32_t now = CURRENT_TOCKSTAMP();
+ struct _le_peak *p = &le->_le.le_peaks[now % NTOCKS];
+
+ if (!TOCKSTAMP_IS_STALE(now, p->le_time) || (balance > p->le_max)) {
+ /*
+ * The current balance is greater than the previously
+ * observed peak for the current time block, *or* we
+ * haven't yet recorded a peak for the current time block --
+ * so this is our new peak.
+ *
+ * (We only track the lower 32-bits of a balance for rolling
+ * max purposes.)
+ */
+ p->le_max = (uint32_t)balance;
+ p->le_time = now;
+ }
}
- ledger_unlock(ledger->ledger_parent);
- /*
- * XXX The spec says that you have to destroy all objects that
- * have been created with this ledger. Nice work eh? For now
- * Transfer the balance to the parent and let it worry about
- * it.
- */
- /* XXX the parent ledger inherits the debt ?? */
- (void) ledger_enter(ledger->ledger_parent, ledger->ledger_balance);
-
- /* adjust the balance of the creation ledger */
- (void) ledger_enter(ledger->ledger_ledger, -sizeof(*ledger));
+ /* Check to see whether we're due a refill */
+ if (le->le_flags & LF_REFILL_SCHEDULED) {
+ uint64_t now = mach_absolute_time();
+ if ((now - le->_le.le_refill.le_last_refill) > le->_le.le_refill.le_refill_period)
+ ledger_refill(now, ledger, entry);
+ }
- /* delete the ledger */
- ledger_deallocate(ledger);
+ if (limit_exceeded(le)) {
+ /*
+ * We've exceeded the limit for this entry. There
+ * are several possible ways to handle it. We can block,
+ * we can execute a callback, or we can ignore it. In
+ * either of the first two cases, we want to set the AST
+ * flag so we can take the appropriate action just before
+ * leaving the kernel. The one caveat is that if we have
+ * already called the callback, we don't want to do it
+ * again until it gets rearmed.
+ */
+ if ((le->le_flags & LEDGER_ACTION_BLOCK) ||
+ (!(le->le_flags & LF_CALLED_BACK) &&
+ entry_get_callback(ledger, entry))) {
+ set_astledger(current_thread());
+ }
+ } else {
+ /*
+ * The balance on the account is below the limit.
+ *
+ * If there are any threads blocked on this entry, now would
+ * be a good time to wake them up.
+ */
+ if (le->le_flags & LF_WAKE_NEEDED)
+ ledger_limit_entry_wakeup(le);
- return(KERN_SUCCESS);
+ if (le->le_flags & LEDGER_ACTION_CALLBACK) {
+ /*
+ * Client has requested that a callback be invoked whenever
+ * the ledger's balance crosses into or out of the warning
+ * level.
+ */
+ if (warn_level_exceeded(le)) {
+ /*
+ * This ledger's balance is above the warning level.
+ */
+ if ((le->le_flags & LF_WARNED) == 0) {
+ /*
+ * If we are above the warning level and
+ * have not yet invoked the callback,
+ * set the AST so it can be done before returning
+ * to userland.
+ */
+ set_astledger(current_thread());
+ }
+ } else {
+ /*
+ * This ledger's balance is below the warning level.
+ */
+ if (le->le_flags & LF_WARNED) {
+ /*
+ * If we are below the warning level and
+ * the LF_WARNED flag is still set, we need
+ * to invoke the callback to let the client
+ * know the ledger balance is now back below
+ * the warning level.
+ */
+ set_astledger(current_thread());
+ }
+ }
+ }
+ }
+
+ if ((le->le_flags & LF_PANIC_ON_NEGATIVE) &&
+ (le->le_credit < le->le_debit)) {
+ panic("ledger_check_new_balance(%p,%d): negative ledger %p balance:%lld\n",
+ ledger, entry, le, le->le_credit - le->le_debit);
+ }
}
/*
- * Return the ledger limit and balance
+ * Add value to an entry in a ledger.
*/
-kern_return_t ledger_read(
- ledger_t ledger,
- ledger_item_t *balance,
- ledger_item_t *limit)
+kern_return_t
+ledger_credit(ledger_t ledger, int entry, ledger_amount_t amount)
{
- if (ledger == LEDGER_NULL)
- return(KERN_INVALID_ARGUMENT);
-
- ledger_lock(ledger);
- *balance = ledger->ledger_balance;
- *limit = ledger->ledger_limit;
- ledger_unlock(ledger);
+ ledger_amount_t old, new;
+ struct ledger_entry *le;
- return(KERN_SUCCESS);
+ if (!ENTRY_VALID(ledger, entry) || (amount < 0))
+ return (KERN_INVALID_VALUE);
+
+ if (amount == 0)
+ return (KERN_SUCCESS);
+
+ le = &ledger->l_entries[entry];
+
+ old = OSAddAtomic64(amount, &le->le_credit);
+ new = old + amount;
+ lprintf(("%p Credit %lld->%lld\n", current_thread(), old, new));
+ ledger_check_new_balance(ledger, entry);
+
+ return (KERN_SUCCESS);
+}
+
+/* Add all of one ledger's values into another.
+ * They must have been created from the same template.
+ * This is not done atomically. Another thread (if not otherwise synchronized)
+ * may see bogus values when comparing one entry to another.
+ * As each entry's credit & debit are modified one at a time, the warning/limit
+ * may spuriously trip, or spuriously fail to trip, or another thread (if not
+ * otherwise synchronized) may see a bogus balance.
+ */
+kern_return_t
+ledger_rollup(ledger_t to_ledger, ledger_t from_ledger)
+{
+ int i;
+ struct ledger_entry *from_le, *to_le;
+
+ assert(to_ledger->l_template == from_ledger->l_template);
+
+ for (i = 0; i < to_ledger->l_size; i++) {
+ if (ENTRY_VALID(from_ledger, i) && ENTRY_VALID(to_ledger, i)) {
+ from_le = &from_ledger->l_entries[i];
+ to_le = &to_ledger->l_entries[i];
+ OSAddAtomic64(from_le->le_credit, &to_le->le_credit);
+ OSAddAtomic64(from_le->le_debit, &to_le->le_debit);
+ }
+ }
+
+ return (KERN_SUCCESS);
}
/*
- * Transfer resources from a parent ledger to a child
+ * Zero the balance of a ledger by adding to its credit or debit, whichever is smaller.
+ * Note that some clients of ledgers (notably, task wakeup statistics) require that
+ * le_credit only ever increase as a function of ledger_credit().
*/
-kern_return_t ledger_transfer(
- ledger_t parent_ledger,
- ledger_t child_ledger,
- ledger_item_t transfer)
+kern_return_t
+ledger_zero_balance(ledger_t ledger, int entry)
{
-#define abs(v) ((v) > 0)?(v):-(v)
-
- ledger_t src, dest;
- ledger_item_t amount = abs(transfer);
-
- if (parent_ledger == LEDGER_NULL)
- return(KERN_INVALID_ARGUMENT);
+ struct ledger_entry *le;
- if (child_ledger == LEDGER_NULL)
- return(KERN_INVALID_ARGUMENT);
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
- /* Must be different ledgers */
- if (parent_ledger == child_ledger)
- return(KERN_INVALID_ARGUMENT);
+ le = &ledger->l_entries[entry];
- if (transfer == 0)
- return(KERN_SUCCESS);
-
- ledger_lock(child_ledger);
- ledger_lock(parent_ledger);
+top:
+ if (le->le_credit > le->le_debit) {
+ if (!OSCompareAndSwap64(le->le_debit, le->le_credit, &le->le_debit))
+ goto top;
+ lprintf(("%p zeroed %lld->%lld\n", current_thread(), le->le_debit, le->le_credit));
+ } else if (le->le_credit < le->le_debit) {
+ if (!OSCompareAndSwap64(le->le_credit, le->le_debit, &le->le_credit))
+ goto top;
+ lprintf(("%p zeroed %lld->%lld\n", current_thread(), le->le_credit, le->le_debit));
+ }
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_get_limit(ledger_t ledger, int entry, ledger_amount_t *limit)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ le = &ledger->l_entries[entry];
+ *limit = le->le_limit;
+
+ lprintf(("ledger_get_limit: %lld\n", *limit));
- /* XXX Should be the parent you created it from ?? */
- if (parent_ledger != child_ledger->ledger_parent) {
- ledger_unlock(parent_ledger);
- ledger_unlock(child_ledger);
- return(KERN_INVALID_LEDGER);
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Adjust the limit of a limited resource. This does not affect the
+ * current balance, so the change doesn't affect the thread until the
+ * next refill.
+ *
+ * warn_level: If non-zero, causes the callback to be invoked when
+ * the balance exceeds this level. Specified as a percentage [of the limit].
+ */
+kern_return_t
+ledger_set_limit(ledger_t ledger, int entry, ledger_amount_t limit,
+ uint8_t warn_level_percentage)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ lprintf(("ledger_set_limit: %lld\n", limit));
+ le = &ledger->l_entries[entry];
+
+ if (limit == LEDGER_LIMIT_INFINITY) {
+ /*
+ * Caller wishes to disable the limit. This will implicitly
+ * disable automatic refill, as refills implicitly depend
+ * on the limit.
+ */
+ ledger_disable_refill(ledger, entry);
}
- if (transfer > 0) {
- dest = child_ledger;
- src = parent_ledger;
+ le->le_limit = limit;
+ le->_le.le_refill.le_last_refill = 0;
+ flag_clear(&le->le_flags, LF_CALLED_BACK);
+ flag_clear(&le->le_flags, LF_WARNED);
+ ledger_limit_entry_wakeup(le);
+
+ if (warn_level_percentage != 0) {
+ assert(warn_level_percentage <= 100);
+ assert(limit > 0); /* no negative limit support for warnings */
+ assert(limit != LEDGER_LIMIT_INFINITY); /* warn % without limit makes no sense */
+ le->le_warn_level = (le->le_limit * warn_level_percentage) / 100;
+ } else {
+ le->le_warn_level = LEDGER_LIMIT_INFINITY;
}
- else {
- src = child_ledger;
- dest = parent_ledger;
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_get_maximum(ledger_t ledger, int entry,
+ ledger_amount_t *max_observed_balance)
+{
+ struct ledger_entry *le;
+ uint32_t now = CURRENT_TOCKSTAMP();
+ int i;
+
+ le = &ledger->l_entries[entry];
+
+ if (!ENTRY_VALID(ledger, entry) || !(le->le_flags & LF_TRACKING_MAX)) {
+ return (KERN_INVALID_VALUE);
}
- if (src->ledger_limit != LEDGER_ITEM_INFINITY) {
- /* Would the existing balance exceed the new limit ? */
- if (src->ledger_limit - amount < src->ledger_balance) {
- ledger_unlock(parent_ledger);
- ledger_unlock(child_ledger);
- return(KERN_RESOURCE_SHORTAGE);
+ /*
+ * Start with the current balance; if neither of the recorded peaks are
+ * within recent history, we use this.
+ */
+ *max_observed_balance = le->le_credit - le->le_debit;
+
+ for (i = 0; i < NTOCKS; i++) {
+ if (!TOCKSTAMP_IS_STALE(now, le->_le.le_peaks[i].le_time) &&
+ (le->_le.le_peaks[i].le_max > *max_observed_balance)) {
+ /*
+ * The peak for this time block isn't stale, and it
+ * is greater than the current balance -- so use it.
+ */
+ *max_observed_balance = le->_le.le_peaks[i].le_max;
}
- if (src->ledger_limit - amount > 0)
- src->ledger_limit -= amount;
- else
- src->ledger_limit = 0;
}
+
+ lprintf(("ledger_get_maximum: %lld\n", *max_observed_balance));
+
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Enable tracking of periodic maximums for this ledger entry.
+ */
+kern_return_t
+ledger_track_maximum(ledger_template_t template, int entry,
+ __unused int period_in_secs)
+{
+ template_lock(template);
- if (dest->ledger_limit != LEDGER_ITEM_INFINITY) {
- if ((natural_t)(dest->ledger_limit + amount)
- < LEDGER_ITEM_INFINITY)
- dest->ledger_limit += amount;
- else
- dest->ledger_limit = (LEDGER_ITEM_INFINITY - 1);
+ if ((entry < 0) || (entry >= template->lt_cnt)) {
+ template_unlock(template);
+ return (KERN_INVALID_VALUE);
}
- ledger_unlock(parent_ledger);
- ledger_unlock(child_ledger);
-
- return(KERN_SUCCESS);
-#undef abs
+ template->lt_entries[entry].et_flags |= LF_TRACKING_MAX;
+ template_unlock(template);
+
+ return (KERN_SUCCESS);
}
+kern_return_t
+ledger_panic_on_negative(ledger_template_t template, int entry)
+{
+ template_lock(template);
+
+ if ((entry < 0) || (entry >= template->lt_cnt)) {
+ template_unlock(template);
+ return (KERN_INVALID_VALUE);
+ }
+
+ template->lt_entries[entry].et_flags |= LF_PANIC_ON_NEGATIVE;
+
+ template_unlock(template);
+
+ return (KERN_SUCCESS);
+}
/*
- * Routine: convert_port_to_ledger
- * Purpose:
- * Convert from a port to a ledger.
- * Doesn't consume the port ref; the ledger produced may be null.
- * Conditions:
- * Nothing locked.
+ * Add a callback to be executed when the resource goes into deficit.
*/
-
-ledger_t
-convert_port_to_ledger(
- ipc_port_t port)
+kern_return_t
+ledger_set_callback(ledger_template_t template, int entry,
+ ledger_callback_t func, const void *param0, const void *param1)
{
- ledger_t ledger = LEDGER_NULL;
+ struct entry_template *et;
+ struct ledger_callback *old_cb, *new_cb;
- if (IP_VALID(port)) {
- ip_lock(port);
- if (ip_active(port) &&
- (ip_kotype(port) == IKOT_LEDGER))
- ledger = (ledger_t) port->ip_kobject;
- ip_unlock(port);
+ if ((entry < 0) || (entry >= template->lt_cnt))
+ return (KERN_INVALID_VALUE);
+
+ if (func) {
+ new_cb = (struct ledger_callback *)kalloc(sizeof (*new_cb));
+ new_cb->lc_func = func;
+ new_cb->lc_param0 = param0;
+ new_cb->lc_param1 = param1;
+ } else {
+ new_cb = NULL;
}
- return ledger;
+ template_lock(template);
+ et = &template->lt_entries[entry];
+ old_cb = et->et_callback;
+ et->et_callback = new_cb;
+ template_unlock(template);
+ if (old_cb)
+ kfree(old_cb, sizeof (*old_cb));
+
+ return (KERN_SUCCESS);
}
/*
- * Routine: convert_ledger_to_port
- * Purpose:
- * Convert from a ledger to a port.
- * Produces a naked send right which may be invalid.
- * Conditions:
- * Nothing locked.
+ * Disable callback notification for a specific ledger entry.
+ *
+ * Otherwise, if using a ledger template which specified a
+ * callback function (ledger_set_callback()), it will be invoked when
+ * the resource goes into deficit.
*/
+kern_return_t
+ledger_disable_callback(ledger_t ledger, int entry)
+{
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ /*
+ * le_warn_level is used to indicate *if* this ledger has a warning configured,
+ * in addition to what that warning level is set to.
+ * This means a side-effect of ledger_disable_callback() is that the
+ * warning level is forgotten.
+ */
+ ledger->l_entries[entry].le_warn_level = LEDGER_LIMIT_INFINITY;
+ flag_clear(&ledger->l_entries[entry].le_flags, LEDGER_ACTION_CALLBACK);
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Enable callback notification for a specific ledger entry.
+ *
+ * This is only needed if ledger_disable_callback() has previously
+ * been invoked against an entry; there must already be a callback
+ * configured.
+ */
+kern_return_t
+ledger_enable_callback(ledger_t ledger, int entry)
+{
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ assert(entry_get_callback(ledger, entry) != NULL);
+
+ flag_set(&ledger->l_entries[entry].le_flags, LEDGER_ACTION_CALLBACK);
+ return (KERN_SUCCESS);
+}
-ipc_port_t
-convert_ledger_to_port(
- ledger_t ledger)
+/*
+ * Query the automatic refill period for this ledger entry.
+ *
+ * A period of 0 means this entry has none configured.
+ */
+kern_return_t
+ledger_get_period(ledger_t ledger, int entry, uint64_t *period)
{
- ipc_port_t port;
+ struct ledger_entry *le;
- port = ipc_port_make_send(ledger->ledger_self);
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
- return port;
+ le = &ledger->l_entries[entry];
+ *period = abstime_to_nsecs(le->_le.le_refill.le_refill_period);
+ lprintf(("ledger_get_period: %llx\n", *period));
+ return (KERN_SUCCESS);
}
/*
- * Copy a ledger
+ * Adjust the automatic refill period.
*/
-ipc_port_t
-ledger_copy(
- ledger_t ledger)
+kern_return_t
+ledger_set_period(ledger_t ledger, int entry, uint64_t period)
+{
+ struct ledger_entry *le;
+
+ lprintf(("ledger_set_period: %llx\n", period));
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ le = &ledger->l_entries[entry];
+
+ /*
+ * A refill period refills the ledger in multiples of the limit,
+ * so if you haven't set one yet, you need a lesson on ledgers.
+ */
+ assert(le->le_limit != LEDGER_LIMIT_INFINITY);
+
+ if (le->le_flags & LF_TRACKING_MAX) {
+ /*
+ * Refill is incompatible with rolling max tracking.
+ */
+ return (KERN_INVALID_VALUE);
+ }
+
+ le->_le.le_refill.le_refill_period = nsecs_to_abstime(period);
+
+ /*
+ * Set the 'starting time' for the next refill to now. Since
+ * we're resetting the balance to zero here, we consider this
+ * moment the starting time for accumulating a balance that
+ * counts towards the limit.
+ */
+ le->_le.le_refill.le_last_refill = mach_absolute_time();
+ ledger_zero_balance(ledger, entry);
+
+ flag_set(&le->le_flags, LF_REFILL_SCHEDULED);
+
+ return (KERN_SUCCESS);
+}
+
+/*
+ * Disable automatic refill.
+ */
+kern_return_t
+ledger_disable_refill(ledger_t ledger, int entry)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ le = &ledger->l_entries[entry];
+
+ flag_clear(&le->le_flags, LF_REFILL_SCHEDULED);
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_get_actions(ledger_t ledger, int entry, int *actions)
+{
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ *actions = ledger->l_entries[entry].le_flags & LEDGER_ACTION_MASK;
+ lprintf(("ledger_get_actions: %#x\n", *actions));
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_set_action(ledger_t ledger, int entry, int action)
+{
+ lprintf(("ledger_set_action: %#x\n", action));
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_VALUE);
+
+ flag_set(&ledger->l_entries[entry].le_flags, action);
+ return (KERN_SUCCESS);
+}
+
+void
+set_astledger(thread_t thread)
+{
+ spl_t s = splsched();
+
+ if (thread == current_thread()) {
+ thread_ast_set(thread, AST_LEDGER);
+ ast_propagate(thread->ast);
+ } else {
+ processor_t p;
+
+ thread_lock(thread);
+ thread_ast_set(thread, AST_LEDGER);
+ p = thread->last_processor;
+ if ((p != PROCESSOR_NULL) && (p->state == PROCESSOR_RUNNING) &&
+ (p->active_thread == thread))
+ cause_ast_check(p);
+ thread_unlock(thread);
+ }
+
+ splx(s);
+}
+
+kern_return_t
+ledger_debit(ledger_t ledger, int entry, ledger_amount_t amount)
+{
+ struct ledger_entry *le;
+ ledger_amount_t old, new;
+
+ if (!ENTRY_VALID(ledger, entry) || (amount < 0))
+ return (KERN_INVALID_ARGUMENT);
+
+ if (amount == 0)
+ return (KERN_SUCCESS);
+
+ le = &ledger->l_entries[entry];
+
+ old = OSAddAtomic64(amount, &le->le_debit);
+ new = old + amount;
+
+ lprintf(("%p Debit %lld->%lld\n", thread, old, new));
+ ledger_check_new_balance(ledger, entry);
+ return (KERN_SUCCESS);
+
+}
+
+void
+ledger_ast(thread_t thread)
+{
+ struct ledger *l = thread->t_ledger;
+ struct ledger *thl;
+ uint32_t block;
+ uint64_t now;
+ uint8_t task_flags;
+ uint8_t task_percentage;
+ uint64_t task_interval;
+
+ kern_return_t ret;
+ task_t task = thread->task;
+
+ lprintf(("Ledger AST for %p\n", thread));
+
+ ASSERT(task != NULL);
+ ASSERT(thread == current_thread());
+
+top:
+ /*
+ * Take a self-consistent snapshot of the CPU usage monitor parameters. The task
+ * can change them at any point (with the task locked).
+ */
+ task_lock(task);
+ task_flags = task->rusage_cpu_flags;
+ task_percentage = task->rusage_cpu_perthr_percentage;
+ task_interval = task->rusage_cpu_perthr_interval;
+ task_unlock(task);
+
+ /*
+ * Make sure this thread is up to date with regards to any task-wide per-thread
+ * CPU limit, but only if it doesn't have a thread-private blocking CPU limit.
+ */
+ if (((task_flags & TASK_RUSECPU_FLAGS_PERTHR_LIMIT) != 0) &&
+ ((thread->options & TH_OPT_PRVT_CPULIMIT) == 0)) {
+ uint8_t percentage;
+ uint64_t interval;
+ int action;
+
+ thread_get_cpulimit(&action, &percentage, &interval);
+
+ /*
+ * If the thread's CPU limits no longer match the task's, or the
+ * task has a limit but the thread doesn't, update the limit.
+ */
+ if (((thread->options & TH_OPT_PROC_CPULIMIT) == 0) ||
+ (interval != task_interval) || (percentage != task_percentage)) {
+ thread_set_cpulimit(THREAD_CPULIMIT_EXCEPTION, task_percentage, task_interval);
+ assert((thread->options & TH_OPT_PROC_CPULIMIT) != 0);
+ }
+ } else if (((task_flags & TASK_RUSECPU_FLAGS_PERTHR_LIMIT) == 0) &&
+ (thread->options & TH_OPT_PROC_CPULIMIT)) {
+ assert((thread->options & TH_OPT_PRVT_CPULIMIT) == 0);
+
+ /*
+ * Task no longer has a per-thread CPU limit; remove this thread's
+ * corresponding CPU limit.
+ */
+ thread_set_cpulimit(THREAD_CPULIMIT_DISABLE, 0, 0);
+ assert((thread->options & TH_OPT_PROC_CPULIMIT) == 0);
+ }
+
+ /*
+ * If the task or thread is being terminated, let's just get on with it
+ */
+ if ((l == NULL) || !task->active || task->halting || !thread->active)
+ return;
+
+ /*
+ * Examine all entries in deficit to see which might be eligble for
+ * an automatic refill, which require callbacks to be issued, and
+ * which require blocking.
+ */
+ block = 0;
+ now = mach_absolute_time();
+
+ /*
+ * Note that thread->t_threadledger may have been changed by the
+ * thread_set_cpulimit() call above - so don't examine it until afterwards.
+ */
+ thl = thread->t_threadledger;
+ if (LEDGER_VALID(thl)) {
+ block |= ledger_check_needblock(thl, now);
+ }
+ block |= ledger_check_needblock(l, now);
+
+ /*
+ * If we are supposed to block on the availability of one or more
+ * resources, find the first entry in deficit for which we should wait.
+ * Schedule a refill if necessary and then sleep until the resource
+ * becomes available.
+ */
+ if (block) {
+ if (LEDGER_VALID(thl)) {
+ ret = ledger_perform_blocking(thl);
+ if (ret != KERN_SUCCESS)
+ goto top;
+ }
+ ret = ledger_perform_blocking(l);
+ if (ret != KERN_SUCCESS)
+ goto top;
+ } /* block */
+}
+
+static uint32_t
+ledger_check_needblock(ledger_t l, uint64_t now)
{
- /* XXX reference counting */
- assert(ledger);
- return(ipc_port_copy_send(ledger->ledger_self));
+ int i;
+ uint32_t flags, block = 0;
+ struct ledger_entry *le;
+ struct ledger_callback *lc;
+
+
+ for (i = 0; i < l->l_size; i++) {
+ le = &l->l_entries[i];
+
+ lc = entry_get_callback(l, i);
+
+ if (limit_exceeded(le) == FALSE) {
+ if (le->le_flags & LEDGER_ACTION_CALLBACK) {
+ /*
+ * If needed, invoke the callback as a warning.
+ * This needs to happen both when the balance rises above
+ * the warning level, and also when it dips back below it.
+ */
+ assert(lc != NULL);
+ /*
+ * See comments for matching logic in ledger_check_new_balance().
+ */
+ if (warn_level_exceeded(le)) {
+ flags = flag_set(&le->le_flags, LF_WARNED);
+ if ((flags & LF_WARNED) == 0) {
+ lc->lc_func(LEDGER_WARNING_ROSE_ABOVE, lc->lc_param0, lc->lc_param1);
+ }
+ } else {
+ flags = flag_clear(&le->le_flags, LF_WARNED);
+ if (flags & LF_WARNED) {
+ lc->lc_func(LEDGER_WARNING_DIPPED_BELOW, lc->lc_param0, lc->lc_param1);
+ }
+ }
+ }
+
+ continue;
+ }
+
+ /* We're over the limit, so refill if we are eligible and past due. */
+ if (le->le_flags & LF_REFILL_SCHEDULED) {
+ if ((le->_le.le_refill.le_last_refill + le->_le.le_refill.le_refill_period) > now) {
+ ledger_refill(now, l, i);
+ if (limit_exceeded(le) == FALSE)
+ continue;
+ }
+ }
+
+ if (le->le_flags & LEDGER_ACTION_BLOCK)
+ block = 1;
+ if ((le->le_flags & LEDGER_ACTION_CALLBACK) == 0)
+ continue;
+
+ /*
+ * If the LEDGER_ACTION_CALLBACK flag is on, we expect there to
+ * be a registered callback.
+ */
+ assert(lc != NULL);
+ flags = flag_set(&le->le_flags, LF_CALLED_BACK);
+ /* Callback has already been called */
+ if (flags & LF_CALLED_BACK)
+ continue;
+ lc->lc_func(FALSE, lc->lc_param0, lc->lc_param1);
+ }
+ return(block);
+}
+
+
+/* return KERN_SUCCESS to continue, KERN_FAILURE to restart */
+static kern_return_t
+ledger_perform_blocking(ledger_t l)
+{
+ int i;
+ kern_return_t ret;
+ struct ledger_entry *le;
+
+ for (i = 0; i < l->l_size; i++) {
+ le = &l->l_entries[i];
+ if ((!limit_exceeded(le)) ||
+ ((le->le_flags & LEDGER_ACTION_BLOCK) == 0))
+ continue;
+
+ /* Prepare to sleep until the resource is refilled */
+ ret = assert_wait_deadline(le, TRUE,
+ le->_le.le_refill.le_last_refill + le->_le.le_refill.le_refill_period);
+ if (ret != THREAD_WAITING)
+ return(KERN_SUCCESS);
+
+ /* Mark that somebody is waiting on this entry */
+ flag_set(&le->le_flags, LF_WAKE_NEEDED);
+
+ ret = thread_block_reason(THREAD_CONTINUE_NULL, NULL,
+ AST_LEDGER);
+ if (ret != THREAD_AWAKENED)
+ return(KERN_SUCCESS);
+
+ /*
+ * The world may have changed while we were asleep.
+ * Some other resource we need may have gone into
+ * deficit. Or maybe we're supposed to die now.
+ * Go back to the top and reevaluate.
+ */
+ return(KERN_FAILURE);
+ }
+ return(KERN_SUCCESS);
+}
+
+
+kern_return_t
+ledger_get_entries(ledger_t ledger, int entry, ledger_amount_t *credit,
+ ledger_amount_t *debit)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_ARGUMENT);
+
+ le = &ledger->l_entries[entry];
+
+ *credit = le->le_credit;
+ *debit = le->le_debit;
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_reset_callback_state(ledger_t ledger, int entry)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_ARGUMENT);
+
+ le = &ledger->l_entries[entry];
+
+ flag_clear(&le->le_flags, LF_CALLED_BACK);
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_disable_panic_on_negative(ledger_t ledger, int entry)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_ARGUMENT);
+
+ le = &ledger->l_entries[entry];
+
+ flag_clear(&le->le_flags, LF_PANIC_ON_NEGATIVE);
+
+ return (KERN_SUCCESS);
+}
+
+kern_return_t
+ledger_get_balance(ledger_t ledger, int entry, ledger_amount_t *balance)
+{
+ struct ledger_entry *le;
+
+ if (!ENTRY_VALID(ledger, entry))
+ return (KERN_INVALID_ARGUMENT);
+
+ le = &ledger->l_entries[entry];
+
+ assert((le->le_credit >= 0) && (le->le_debit >= 0));
+
+ *balance = le->le_credit - le->le_debit;
+
+ return (KERN_SUCCESS);
+}
+
+int
+ledger_template_info(void **buf, int *len)
+{
+ struct ledger_template_info *lti;
+ struct entry_template *et;
+ int i;
+ ledger_t l;
+
+ /*
+ * Since all tasks share a ledger template, we'll just use the
+ * caller's as the source.
+ */
+ l = current_task()->ledger;
+ if ((*len < 0) || (l == NULL))
+ return (EINVAL);
+
+ if (*len > l->l_size)
+ *len = l->l_size;
+ lti = kalloc((*len) * sizeof (struct ledger_template_info));
+ if (lti == NULL)
+ return (ENOMEM);
+ *buf = lti;
+
+ template_lock(l->l_template);
+ et = l->l_template->lt_entries;
+
+ for (i = 0; i < *len; i++) {
+ memset(lti, 0, sizeof (*lti));
+ strlcpy(lti->lti_name, et->et_key, LEDGER_NAME_MAX);
+ strlcpy(lti->lti_group, et->et_group, LEDGER_NAME_MAX);
+ strlcpy(lti->lti_units, et->et_units, LEDGER_NAME_MAX);
+ et++;
+ lti++;
+ }
+ template_unlock(l->l_template);
+
+ return (0);
+}
+
+static void
+ledger_fill_entry_info(struct ledger_entry *le,
+ struct ledger_entry_info *lei,
+ uint64_t now)
+{
+ assert(le != NULL);
+ assert(lei != NULL);
+
+ memset(lei, 0, sizeof (*lei));
+
+ lei->lei_limit = le->le_limit;
+ lei->lei_credit = le->le_credit;
+ lei->lei_debit = le->le_debit;
+ lei->lei_balance = lei->lei_credit - lei->lei_debit;
+ lei->lei_refill_period = (le->le_flags & LF_REFILL_SCHEDULED) ?
+ abstime_to_nsecs(le->_le.le_refill.le_refill_period) : 0;
+ lei->lei_last_refill = abstime_to_nsecs(now - le->_le.le_refill.le_last_refill);
+}
+
+int
+ledger_get_task_entry_info_multiple(task_t task, void **buf, int *len)
+{
+ struct ledger_entry_info *lei;
+ struct ledger_entry *le;
+ uint64_t now = mach_absolute_time();
+ int i;
+ ledger_t l;
+
+ if ((*len < 0) || ((l = task->ledger) == NULL))
+ return (EINVAL);
+
+ if (*len > l->l_size)
+ *len = l->l_size;
+ lei = kalloc((*len) * sizeof (struct ledger_entry_info));
+ if (lei == NULL)
+ return (ENOMEM);
+ *buf = lei;
+
+ le = l->l_entries;
+
+ for (i = 0; i < *len; i++) {
+ ledger_fill_entry_info(le, lei, now);
+ le++;
+ lei++;
+ }
+
+ return (0);
+}
+
+void
+ledger_get_entry_info(ledger_t ledger,
+ int entry,
+ struct ledger_entry_info *lei)
+{
+ uint64_t now = mach_absolute_time();
+
+ assert(ledger != NULL);
+ assert(lei != NULL);
+ assert(entry < ledger->l_size);
+
+ struct ledger_entry *le = &ledger->l_entries[entry];
+
+ ledger_fill_entry_info(le, lei, now);
+}
+
+int
+ledger_info(task_t task, struct ledger_info *info)
+{
+ ledger_t l;
+
+ if ((l = task->ledger) == NULL)
+ return (ENOENT);
+
+ memset(info, 0, sizeof (*info));
+
+ strlcpy(info->li_name, l->l_template->lt_name, LEDGER_NAME_MAX);
+ info->li_id = l->l_id;
+ info->li_entries = l->l_size;
+ return (0);
+}
+
+#ifdef LEDGER_DEBUG
+int
+ledger_limit(task_t task, struct ledger_limit_args *args)
+{
+ ledger_t l;
+ int64_t limit;
+ int idx;
+
+ if ((l = task->ledger) == NULL)
+ return (EINVAL);
+
+ idx = ledger_key_lookup(l->l_template, args->lla_name);
+ if ((idx < 0) || (idx >= l->l_size))
+ return (EINVAL);
+
+ /*
+ * XXX - this doesn't really seem like the right place to have
+ * a context-sensitive conversion of userspace units into kernel
+ * units. For now I'll handwave and say that the ledger() system
+ * call isn't meant for civilians to use - they should be using
+ * the process policy interfaces.
+ */
+ if (idx == task_ledgers.cpu_time) {
+ int64_t nsecs;
+
+ if (args->lla_refill_period) {
+ /*
+ * If a refill is scheduled, then the limit is
+ * specified as a percentage of one CPU. The
+ * syscall specifies the refill period in terms of
+ * milliseconds, so we need to convert to nsecs.
+ */
+ args->lla_refill_period *= 1000000;
+ nsecs = args->lla_limit *
+ (args->lla_refill_period / 100);
+ lprintf(("CPU limited to %lld nsecs per second\n",
+ nsecs));
+ } else {
+ /*
+ * If no refill is scheduled, then this is a
+ * fixed amount of CPU time (in nsecs) that can
+ * be consumed.
+ */
+ nsecs = args->lla_limit;
+ lprintf(("CPU limited to %lld nsecs\n", nsecs));
+ }
+ limit = nsecs_to_abstime(nsecs);
+ } else {
+ limit = args->lla_limit;
+ lprintf(("%s limited to %lld\n", args->lla_name, limit));
+ }
+
+ if (args->lla_refill_period > 0)
+ ledger_set_period(l, idx, args->lla_refill_period);
+
+ ledger_set_limit(l, idx, limit);
+ flag_set(&l->l_entries[idx].le_flags, LEDGER_ACTION_BLOCK);
+ return (0);
}
+#endif
projects / apple / xnu.git / blobdiff