* Copyright (c) 2009 Apple Inc. All rights reserved.
*
* @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
* 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,
* 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_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <unistd.h>
#include <stdio.h>
#include <math.h>
#include <sys/wait.h>
-#include <sys/syscall.h>
+#include <sys/kdebug.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <semaphore.h>
#include <mach/task.h>
#include <mach/semaphore.h>
+#include <libproc_internal.h>
+
+#include <os/tsd.h> /* private header for _os_cpu_number */
+
typedef enum my_policy_type { MY_POLICY_REALTIME, MY_POLICY_TIMESHARE, MY_POLICY_FIXEDPRI } my_policy_type_t;
-#define DEFAULT_MAX_SLEEP_NS 2000000000ll /* Two seconds */
-#define CONSTRAINT_NANOS (20000000ll) /* 20 ms */
-#define COMPUTATION_NANOS (10000000ll) /* 10 ms */
+#define DEFAULT_MAX_SLEEP_NS 2000000000ll /* Two seconds */
+#define CONSTRAINT_NANOS (20000000ll) /* 20 ms */
+#define COMPUTATION_NANOS (10000000ll) /* 10 ms */
struct mach_timebase_info g_mti;
volatile int cpuno;
};
-extern int cpu_number(void);
-
void *
second_thread(void *args);
int res;
switch (pol) {
- case MY_POLICY_TIMESHARE:
- {
- return 0;
- }
- case MY_POLICY_REALTIME:
- {
- thread_time_constraint_policy_data_t pol;
-
- /* Hard-coded realtime parameters (similar to what Digi uses) */
- pol.period = 100000;
- pol.constraint = CONSTRAINT_NANOS * g_mti.denom / g_mti.numer;
- pol.computation = COMPUTATION_NANOS * g_mti.denom / g_mti.numer;
- pol.preemptible = 0; /* Ignored by OS */
-
- res = thread_policy_set(mach_thread_self(), THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &pol, THREAD_TIME_CONSTRAINT_POLICY_COUNT);
- assert(res == 0, fail);
- break;
- }
- case MY_POLICY_FIXEDPRI:
- {
- thread_extended_policy_data_t pol;
- pol.timeshare = 0;
-
- res = thread_policy_set(mach_thread_self(), THREAD_EXTENDED_POLICY, (thread_policy_t) &pol, THREAD_EXTENDED_POLICY_COUNT);
- assert(res == 0, fail);
- break;
- }
- default:
- {
- printf("invalid policy type\n");
- return 1;
- }
+ case MY_POLICY_TIMESHARE:
+ {
+ return 0;
+ }
+ case MY_POLICY_REALTIME:
+ {
+ thread_time_constraint_policy_data_t pol;
+
+ /* Hard-coded realtime parameters (similar to what Digi uses) */
+ pol.period = 100000;
+ pol.constraint = CONSTRAINT_NANOS * g_mti.denom / g_mti.numer;
+ pol.computation = COMPUTATION_NANOS * g_mti.denom / g_mti.numer;
+ pol.preemptible = 0; /* Ignored by OS */
+
+ res = thread_policy_set(mach_thread_self(), THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &pol, THREAD_TIME_CONSTRAINT_POLICY_COUNT);
+ assert(res == 0, fail);
+ break;
+ }
+ case MY_POLICY_FIXEDPRI:
+ {
+ thread_extended_policy_data_t pol;
+ pol.timeshare = 0;
+
+ res = thread_policy_set(mach_thread_self(), THREAD_EXTENDED_POLICY, (thread_policy_t) &pol, THREAD_EXTENDED_POLICY_COUNT);
+ assert(res == 0, fail);
+ break;
+ }
+ default:
+ {
+ printf("invalid policy type\n");
+ return 1;
+ }
}
return 0;
return 1;
}
-uint64_t
+uint64_t
get_random_sleep_length_abs_ns(uint64_t min_sleep_ns, uint64_t max_sleep_ns)
{
uint64_t tmp;
return min_sleep_ns + tmp;
}
-void
+void
compute_stats(double *values, uint64_t count, double *average_magnitudep, double *maxp, double *minp, double *stddevp)
{
uint64_t i;
}
_avg = _sum / (double)count;
-
+
_dev = 0;
for (i = 0; i < count; i++) {
_dev += pow((values[i] - _avg), 2);
}
-
+
_dev /= count;
_dev = sqrt(_dev);
printf("Min %s jitter: %.1lf%%\n", label, min * 100);
printf("Avg %s jitter: %.1lf%%\n", label, avg * 100);
printf("Stddev: %.1lf%%\n", stddev * 100);
- putchar('\n');
+ putchar('\n');
}
int
opterr = 0;
while ((ch = getopt(argc, argv, "m:n:hs:w")) != -1 && ch != '?') {
switch (ch) {
- case 's':
- /* Specified seed for random)() */
- random_seed = (unsigned)atoi(optarg);
- srandom(random_seed);
- need_seed = FALSE;
- break;
- case 'm':
- /* How long per timer? */
- max_sleep_ns = strtoull(optarg, NULL, 10);
- break;
- case 'n':
- /* How long per timer? */
- min_sleep_ns = strtoull(optarg, NULL, 10);
- break;
- case 'w':
- /* After each timed wait, wakeup another thread */
- wakeup_second_thread = TRUE;
- break;
- case 'h':
- print_usage();
- exit(0);
- break;
- default:
- fprintf(stderr, "Got unexpected result from getopt().\n");
- exit(1);
- break;
+ case 's':
+ /* Specified seed for random)() */
+ random_seed = (unsigned)atoi(optarg);
+ srandom(random_seed);
+ need_seed = FALSE;
+ break;
+ case 'm':
+ /* How long per timer? */
+ max_sleep_ns = strtoull(optarg, NULL, 10);
+ break;
+ case 'n':
+ /* How long per timer? */
+ min_sleep_ns = strtoull(optarg, NULL, 10);
+ break;
+ case 'w':
+ /* After each timed wait, wakeup another thread */
+ wakeup_second_thread = TRUE;
+ break;
+ case 'h':
+ print_usage();
+ exit(0);
+ break;
+ default:
+ fprintf(stderr, "Got unexpected result from getopt().\n");
+ exit(1);
+ break;
}
}
/* How much jitter is so extreme that we should cut a trace point */
too_much = strtoull(argv[2], NULL, 10);
-
+
/* Array for data */
jitter_arr = (double*)malloc(sizeof(*jitter_arr) * iterations);
if (jitter_arr == NULL) {
exit(1);
}
- /*
- * Repeatedly pick a random timer length and
- * try to sleep exactly that long
+ /*
+ * Disable the wake monitor. If we are
+ * performing a large number of
+ * iterations, the wake monitor may
+ * cause this process to get suspended,
+ * thus causing a large jitter value.
+ */
+ if (proc_disable_wakemon(getpid()) != KERN_SUCCESS) {
+ printf("Couldn't disable wake monitor.\n");
+ /* For now, do not exit; this call could be locked down */
+ }
+
+ /*
+ * Repeatedly pick a random timer length and
+ * try to sleep exactly that long
*/
for (i = 0; i < iterations; i++) {
sleep_length_abs = (uint64_t) (get_random_sleep_length_abs_ns(min_sleep_ns, max_sleep_ns) * (((double)g_mti.denom) / ((double)g_mti.numer)));
target_time = mach_absolute_time() + sleep_length_abs;
-
+
/* Sleep */
kret = mach_wait_until(target_time);
wake_time = mach_absolute_time();
-
+
jitter_arr[i] = (double)(wake_time - target_time);
fraction_arr[i] = jitter_arr[i] / ((double)sleep_length_abs);
-
+
/* Too much: cut a tracepoint for a debugger */
if (jitter_arr[i] >= too_much) {
- syscall(SYS_kdebug_trace, 0xeeeeeeee, 0, 0, 0, 0);
+ kdebug_trace(0xeeeee0 | DBG_FUNC_NONE, 0, 0, 0, 0);
}
if (wakeup_second_thread) {
secargs.last_poke_time = mach_absolute_time();
- secargs.cpuno = cpu_number();
+ secargs.cpuno = _os_cpu_number();
OSMemoryBarrier();
kret = semaphore_signal(wakeup_semaphore);
if (kret != KERN_SUCCESS) {
if (kret != KERN_SUCCESS) {
errx(1, "semaphore_wait");
}
-
}
}
/*
- * Compute statistics and output results.
+ * Compute statistics and output results.
*/
compute_stats(jitter_arr, iterations, &avg, &max, &min, &stddev);
compute_stats(fraction_arr, iterations, &avg_fract, &max_fract, &min_fract, &stddev_fract);
print_stats_fract("%", avg_fract, max_fract, min_fract, stddev_fract);
if (wakeup_second_thread) {
-
res = pthread_join(secthread, NULL);
if (res) {
err(1, "pthread_join");
}
compute_stats(wakeup_second_jitter_arr, iterations, &avg, &max, &min, &stddev);
-
+
putchar('\n');
print_stats_us("second jitter", avg, max, min, stddev);
putchar('\n');
printf("%llu/%llu (%.1f%%) wakeups on same CPU\n", secargs.woke_on_same_cpu, iterations,
- 100.0*((double)secargs.woke_on_same_cpu)/iterations);
+ 100.0 * ((double)secargs.woke_on_same_cpu) / iterations);
}
return 0;
exit(1);
}
- /*
- * Repeatedly pick a random timer length and
- * try to sleep exactly that long
+ /*
+ * Repeatedly pick a random timer length and
+ * try to sleep exactly that long
*/
for (i = 0; i < secargs->iterations; i++) {
-
/* Wake up when poked by main thread */
kret = semaphore_wait(secargs->wakeup_semaphore);
if (kret != KERN_SUCCESS) {
}
wake_time = mach_absolute_time();
- cpuno = cpu_number();
+ cpuno = _os_cpu_number();
if (wake_time < secargs->last_poke_time) {
/* Woke in past, unsynchronized mach_absolute_time()? */
-
+
errx(1, "woke in past %llu (%d) < %llu (%d)", wake_time, cpuno, secargs->last_poke_time, secargs->cpuno);
}
}
secargs->wakeup_second_jitter_arr[i] = (double)(wake_time - secargs->last_poke_time);
-
+
/* Too much: cut a tracepoint for a debugger */
if (secargs->wakeup_second_jitter_arr[i] >= secargs->too_much) {
- syscall(SYS_kdebug_trace, 0xeeeeeeef, 0, 0, 0, 0);
+ kdebug_trace(0xeeeee4 | DBG_FUNC_NONE, 0, 0, 0, 0);
}
kret = semaphore_signal(secargs->return_semaphore);
if (kret != KERN_SUCCESS) {
errx(1, "semaphore_signal %d", kret);
}
-
}
return NULL;
projects / apple / xnu.git / blobdiff