/*
* Copyright (c) 2000-2015 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
* 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_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <mach/mach_types.h>
#include <mach/thread_act_server.h>
#include <kern/kern_types.h>
#include <kern/processor.h>
#include <kern/thread.h>
#include <kern/affinity.h>
#include <mach/task_policy.h>
#include <kern/sfi.h>
#include <kern/policy_internal.h>
#include <sys/errno.h>
#include <sys/ulock.h>
#include <mach/machine/sdt.h>
#ifdef MACH_BSD
extern int proc_selfpid(void);
extern char * proc_name_address(void *p);
extern void rethrottle_thread(void * uthread);
#endif /* MACH_BSD */
#define QOS_EXTRACT(q) ((q) & 0xff)
uint32_t qos_override_mode;
#define QOS_OVERRIDE_MODE_OVERHANG_PEAK 0
#define QOS_OVERRIDE_MODE_IGNORE_OVERRIDE 1
#define QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE 2
#define QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_IGNORE_DISPATCH 3
#define QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_SINGLE_MUTEX_OVERRIDE 4
extern zone_t thread_qos_override_zone;
static boolean_t
proc_thread_qos_remove_override_internal(thread_t thread, user_addr_t resource, int resource_type, boolean_t reset, boolean_t squash);
/*
* THREAD_QOS_UNSPECIFIED is assigned the highest tier available, so it does not provide a limit
* to threads that don't have a QoS class set.
*/
const qos_policy_params_t thread_qos_policy_params = {
/*
* This table defines the starting base priority of the thread,
* which will be modified by the thread importance and the task max priority
* before being applied.
*/
.qos_pri[THREAD_QOS_UNSPECIFIED] = 0, /* not consulted */
.qos_pri[THREAD_QOS_USER_INTERACTIVE] = BASEPRI_BACKGROUND, /* i.e. 46 */
.qos_pri[THREAD_QOS_USER_INITIATED] = BASEPRI_USER_INITIATED,
.qos_pri[THREAD_QOS_LEGACY] = BASEPRI_DEFAULT,
.qos_pri[THREAD_QOS_UTILITY] = BASEPRI_UTILITY,
.qos_pri[THREAD_QOS_BACKGROUND] = MAXPRI_THROTTLE,
.qos_pri[THREAD_QOS_MAINTENANCE] = MAXPRI_THROTTLE,
/*
* This table defines the highest IO priority that a thread marked with this
* QoS class can have.
*/
#if CONFIG_EMBEDDED
.qos_iotier[THREAD_QOS_UNSPECIFIED] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_USER_INTERACTIVE] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_USER_INITIATED] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_LEGACY] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_UTILITY] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_BACKGROUND] = THROTTLE_LEVEL_TIER3,
.qos_iotier[THREAD_QOS_MAINTENANCE] = THROTTLE_LEVEL_TIER3,
#else
.qos_iotier[THREAD_QOS_UNSPECIFIED] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_USER_INTERACTIVE] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_USER_INITIATED] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_LEGACY] = THROTTLE_LEVEL_TIER0,
.qos_iotier[THREAD_QOS_UTILITY] = THROTTLE_LEVEL_TIER1,
.qos_iotier[THREAD_QOS_BACKGROUND] = THROTTLE_LEVEL_TIER2, /* possibly overridden by bg_iotier */
.qos_iotier[THREAD_QOS_MAINTENANCE] = THROTTLE_LEVEL_TIER3,
#endif
/*
* This table defines the highest QoS level that
* a thread marked with this QoS class can have.
*/
.qos_through_qos[THREAD_QOS_UNSPECIFIED] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_UNSPECIFIED),
.qos_through_qos[THREAD_QOS_USER_INTERACTIVE] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_0),
.qos_through_qos[THREAD_QOS_USER_INITIATED] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_1),
.qos_through_qos[THREAD_QOS_LEGACY] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_1),
.qos_through_qos[THREAD_QOS_UTILITY] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_2),
.qos_through_qos[THREAD_QOS_BACKGROUND] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_5),
.qos_through_qos[THREAD_QOS_MAINTENANCE] = QOS_EXTRACT(THROUGHPUT_QOS_TIER_5),
.qos_latency_qos[THREAD_QOS_UNSPECIFIED] = QOS_EXTRACT(LATENCY_QOS_TIER_UNSPECIFIED),
.qos_latency_qos[THREAD_QOS_USER_INTERACTIVE] = QOS_EXTRACT(LATENCY_QOS_TIER_0),
.qos_latency_qos[THREAD_QOS_USER_INITIATED] = QOS_EXTRACT(LATENCY_QOS_TIER_1),
.qos_latency_qos[THREAD_QOS_LEGACY] = QOS_EXTRACT(LATENCY_QOS_TIER_1),
.qos_latency_qos[THREAD_QOS_UTILITY] = QOS_EXTRACT(LATENCY_QOS_TIER_3),
.qos_latency_qos[THREAD_QOS_BACKGROUND] = QOS_EXTRACT(LATENCY_QOS_TIER_3),
.qos_latency_qos[THREAD_QOS_MAINTENANCE] = QOS_EXTRACT(LATENCY_QOS_TIER_3),
};
static void
thread_set_user_sched_mode_and_recompute_pri(thread_t thread, sched_mode_t mode);
static int
thread_qos_scaled_relative_priority(int qos, int qos_relprio);
static void
proc_get_thread_policy_bitfield(thread_t thread, thread_policy_state_t info);
static void
proc_set_thread_policy_locked(thread_t thread, int category, int flavor, int value, int value2, task_pend_token_t pend_token);
static void
proc_set_thread_policy_spinlocked(thread_t thread, int category, int flavor, int value, int value2, task_pend_token_t pend_token);
static void
thread_set_requested_policy_spinlocked(thread_t thread, int category, int flavor, int value, int value2);
static int
thread_get_requested_policy_spinlocked(thread_t thread, int category, int flavor, int* value2);
static int
proc_get_thread_policy_locked(thread_t thread, int category, int flavor, int* value2);
static void
thread_policy_update_spinlocked(thread_t thread, boolean_t recompute_priority, task_pend_token_t pend_token);
static void
thread_policy_update_internal_spinlocked(thread_t thread, boolean_t recompute_priority, task_pend_token_t pend_token);
void
thread_policy_init(void) {
if (PE_parse_boot_argn("qos_override_mode", &qos_override_mode, sizeof(qos_override_mode))) {
printf("QOS override mode: 0x%08x\n", qos_override_mode);
} else {
qos_override_mode = QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_SINGLE_MUTEX_OVERRIDE;
}
}
boolean_t
thread_has_qos_policy(thread_t thread) {
return (proc_get_thread_policy(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS) != THREAD_QOS_UNSPECIFIED) ? TRUE : FALSE;
}
static void
thread_remove_qos_policy_locked(thread_t thread,
task_pend_token_t pend_token)
{
__unused int prev_qos = thread->requested_policy.thrp_qos;
DTRACE_PROC2(qos__remove, thread_t, thread, int, prev_qos);
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_AND_RELPRIO,
THREAD_QOS_UNSPECIFIED, 0, pend_token);
}
kern_return_t
thread_remove_qos_policy(thread_t thread)
{
struct task_pend_token pend_token = {};
thread_mtx_lock(thread);
if (!thread->active) {
thread_mtx_unlock(thread);
return KERN_TERMINATED;
}
thread_remove_qos_policy_locked(thread, &pend_token);
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
return KERN_SUCCESS;
}
boolean_t
thread_is_static_param(thread_t thread)
{
if (thread->static_param) {
DTRACE_PROC1(qos__legacy__denied, thread_t, thread);
return TRUE;
}
return FALSE;
}
/*
* Relative priorities can range between 0REL and -15REL. These
* map to QoS-specific ranges, to create non-overlapping priority
* ranges.
*/
static int
thread_qos_scaled_relative_priority(int qos, int qos_relprio)
{
int next_lower_qos;
/* Fast path, since no validation or scaling is needed */
if (qos_relprio == 0) return 0;
switch (qos) {
case THREAD_QOS_USER_INTERACTIVE:
next_lower_qos = THREAD_QOS_USER_INITIATED;
break;
case THREAD_QOS_USER_INITIATED:
next_lower_qos = THREAD_QOS_LEGACY;
break;
case THREAD_QOS_LEGACY:
next_lower_qos = THREAD_QOS_UTILITY;
break;
case THREAD_QOS_UTILITY:
next_lower_qos = THREAD_QOS_BACKGROUND;
break;
case THREAD_QOS_MAINTENANCE:
case THREAD_QOS_BACKGROUND:
next_lower_qos = 0;
break;
default:
panic("Unrecognized QoS %d", qos);
return 0;
}
int prio_range_max = thread_qos_policy_params.qos_pri[qos];
int prio_range_min = next_lower_qos ? thread_qos_policy_params.qos_pri[next_lower_qos] : 0;
/*
* We now have the valid range that the scaled relative priority can map to. Note
* that the lower bound is exclusive, but the upper bound is inclusive. If the
* range is (21,31], 0REL should map to 31 and -15REL should map to 22. We use the
* fact that the max relative priority is -15 and use ">>4" to divide by 16 and discard
* remainder.
*/
int scaled_relprio = -(((prio_range_max - prio_range_min) * (-qos_relprio)) >> 4);
return scaled_relprio;
}
/*
* flag set by -qos-policy-allow boot-arg to allow
* testing thread qos policy from userspace
*/
boolean_t allow_qos_policy_set = FALSE;
kern_return_t
thread_policy_set(
thread_t thread,
thread_policy_flavor_t flavor,
thread_policy_t policy_info,
mach_msg_type_number_t count)
{
thread_qos_policy_data_t req_qos;
kern_return_t kr;
req_qos.qos_tier = THREAD_QOS_UNSPECIFIED;
if (thread == THREAD_NULL)
return (KERN_INVALID_ARGUMENT);
if (allow_qos_policy_set == FALSE) {
if (thread_is_static_param(thread))
return (KERN_POLICY_STATIC);
if (flavor == THREAD_QOS_POLICY)
return (KERN_INVALID_ARGUMENT);
}
/* Threads without static_param set reset their QoS when other policies are applied. */
if (thread->requested_policy.thrp_qos != THREAD_QOS_UNSPECIFIED) {
/* Store the existing tier, if we fail this call it is used to reset back. */
req_qos.qos_tier = thread->requested_policy.thrp_qos;
req_qos.tier_importance = thread->requested_policy.thrp_qos_relprio;
kr = thread_remove_qos_policy(thread);
if (kr != KERN_SUCCESS) {
return kr;
}
}
kr = thread_policy_set_internal(thread, flavor, policy_info, count);
/* Return KERN_QOS_REMOVED instead of KERN_SUCCESS if we succeeded. */
if (req_qos.qos_tier != THREAD_QOS_UNSPECIFIED) {
if (kr != KERN_SUCCESS) {
/* Reset back to our original tier as the set failed. */
(void)thread_policy_set_internal(thread, THREAD_QOS_POLICY, (thread_policy_t)&req_qos, THREAD_QOS_POLICY_COUNT);
}
}
return kr;
}
kern_return_t
thread_policy_set_internal(
thread_t thread,
thread_policy_flavor_t flavor,
thread_policy_t policy_info,
mach_msg_type_number_t count)
{
kern_return_t result = KERN_SUCCESS;
struct task_pend_token pend_token = {};
thread_mtx_lock(thread);
if (!thread->active) {
thread_mtx_unlock(thread);
return (KERN_TERMINATED);
}
switch (flavor) {
case THREAD_EXTENDED_POLICY:
{
boolean_t timeshare = TRUE;
if (count >= THREAD_EXTENDED_POLICY_COUNT) {
thread_extended_policy_t info;
info = (thread_extended_policy_t)policy_info;
timeshare = info->timeshare;
}
sched_mode_t mode = (timeshare == TRUE) ? TH_MODE_TIMESHARE : TH_MODE_FIXED;
spl_t s = splsched();
thread_lock(thread);
thread_set_user_sched_mode_and_recompute_pri(thread, mode);
thread_unlock(thread);
splx(s);
pend_token.tpt_update_thread_sfi = 1;
break;
}
case THREAD_TIME_CONSTRAINT_POLICY:
{
thread_time_constraint_policy_t info;
if (count < THREAD_TIME_CONSTRAINT_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_time_constraint_policy_t)policy_info;
if (info->constraint < info->computation ||
info->computation > max_rt_quantum ||
info->computation < min_rt_quantum ) {
result = KERN_INVALID_ARGUMENT;
break;
}
spl_t s = splsched();
thread_lock(thread);
thread->realtime.period = info->period;
thread->realtime.computation = info->computation;
thread->realtime.constraint = info->constraint;
thread->realtime.preemptible = info->preemptible;
thread_set_user_sched_mode_and_recompute_pri(thread, TH_MODE_REALTIME);
thread_unlock(thread);
splx(s);
pend_token.tpt_update_thread_sfi = 1;
break;
}
case THREAD_PRECEDENCE_POLICY:
{
thread_precedence_policy_t info;
if (count < THREAD_PRECEDENCE_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_precedence_policy_t)policy_info;
spl_t s = splsched();
thread_lock(thread);
thread->importance = info->importance;
thread_recompute_priority(thread);
thread_unlock(thread);
splx(s);
break;
}
case THREAD_AFFINITY_POLICY:
{
thread_affinity_policy_t info;
if (!thread_affinity_is_supported()) {
result = KERN_NOT_SUPPORTED;
break;
}
if (count < THREAD_AFFINITY_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_affinity_policy_t) policy_info;
/*
* Unlock the thread mutex here and
* return directly after calling thread_affinity_set().
* This is necessary for correct lock ordering because
* thread_affinity_set() takes the task lock.
*/
thread_mtx_unlock(thread);
return thread_affinity_set(thread, info->affinity_tag);
}
#if CONFIG_EMBEDDED
case THREAD_BACKGROUND_POLICY:
{
thread_background_policy_t info;
if (count < THREAD_BACKGROUND_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (thread->task != current_task()) {
result = KERN_PROTECTION_FAILURE;
break;
}
info = (thread_background_policy_t) policy_info;
int enable;
if (info->priority == THREAD_BACKGROUND_POLICY_DARWIN_BG)
enable = TASK_POLICY_ENABLE;
else
enable = TASK_POLICY_DISABLE;
int category = (current_thread() == thread) ? TASK_POLICY_INTERNAL : TASK_POLICY_EXTERNAL;
proc_set_thread_policy_locked(thread, category, TASK_POLICY_DARWIN_BG, enable, 0, &pend_token);
break;
}
#endif /* CONFIG_EMBEDDED */
case THREAD_THROUGHPUT_QOS_POLICY:
{
thread_throughput_qos_policy_t info = (thread_throughput_qos_policy_t) policy_info;
thread_throughput_qos_t tqos;
if (count < THREAD_THROUGHPUT_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if ((result = qos_throughput_policy_validate(info->thread_throughput_qos_tier)) != KERN_SUCCESS)
break;
tqos = qos_extract(info->thread_throughput_qos_tier);
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_THROUGH_QOS, tqos, 0, &pend_token);
break;
}
case THREAD_LATENCY_QOS_POLICY:
{
thread_latency_qos_policy_t info = (thread_latency_qos_policy_t) policy_info;
thread_latency_qos_t lqos;
if (count < THREAD_LATENCY_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if ((result = qos_latency_policy_validate(info->thread_latency_qos_tier)) != KERN_SUCCESS)
break;
lqos = qos_extract(info->thread_latency_qos_tier);
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_LATENCY_QOS, lqos, 0, &pend_token);
break;
}
case THREAD_QOS_POLICY:
{
thread_qos_policy_t info = (thread_qos_policy_t)policy_info;
if (count < THREAD_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (info->qos_tier < 0 || info->qos_tier >= THREAD_QOS_LAST) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (info->tier_importance > 0 || info->tier_importance < THREAD_QOS_MIN_TIER_IMPORTANCE) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (info->qos_tier == THREAD_QOS_UNSPECIFIED && info->tier_importance != 0) {
result = KERN_INVALID_ARGUMENT;
break;
}
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_AND_RELPRIO,
info->qos_tier, -info->tier_importance, &pend_token);
break;
}
default:
result = KERN_INVALID_ARGUMENT;
break;
}
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
return (result);
}
/*
* Note that there is no implemented difference between POLICY_RR and POLICY_FIFO.
* Both result in FIXED mode scheduling.
*/
static sched_mode_t
convert_policy_to_sched_mode(integer_t policy) {
switch (policy) {
case POLICY_TIMESHARE:
return TH_MODE_TIMESHARE;
case POLICY_RR:
case POLICY_FIFO:
return TH_MODE_FIXED;
default:
panic("unexpected sched policy: %d", policy);
return TH_MODE_NONE;
}
}
/*
* Called either with the thread mutex locked
* or from the pthread kext in a 'safe place'.
*/
static kern_return_t
thread_set_mode_and_absolute_pri_internal(thread_t thread,
sched_mode_t mode,
integer_t priority,
task_pend_token_t pend_token)
{
kern_return_t kr = KERN_SUCCESS;
spl_t s = splsched();
thread_lock(thread);
/* This path isn't allowed to change a thread out of realtime. */
if ((thread->sched_mode == TH_MODE_REALTIME) ||
(thread->saved_mode == TH_MODE_REALTIME)) {
kr = KERN_FAILURE;
goto unlock;
}
if (thread->policy_reset) {
kr = KERN_SUCCESS;
goto unlock;
}
sched_mode_t old_mode = thread->sched_mode;
/*
* Reverse engineer and apply the correct importance value
* from the requested absolute priority value.
*
* TODO: Store the absolute priority value instead
*/
if (priority >= thread->max_priority)
priority = thread->max_priority - thread->task_priority;
else if (priority >= MINPRI_KERNEL)
priority -= MINPRI_KERNEL;
else if (priority >= MINPRI_RESERVED)
priority -= MINPRI_RESERVED;
else
priority -= BASEPRI_DEFAULT;
priority += thread->task_priority;
if (priority > thread->max_priority)
priority = thread->max_priority;
else if (priority < MINPRI)
priority = MINPRI;
thread->importance = priority - thread->task_priority;
thread_set_user_sched_mode_and_recompute_pri(thread, mode);
if (mode != old_mode)
pend_token->tpt_update_thread_sfi = 1;
unlock:
thread_unlock(thread);
splx(s);
return kr;
}
/*
* KPI for pthread kext
*
* Set scheduling policy & absolute priority for thread
* May be called from waitqueue callout context with spinlocks held
* Thread mutex lock is not held
*/
kern_return_t
thread_set_workq_pri(thread_t thread,
integer_t priority,
integer_t policy)
{
struct task_pend_token pend_token = {};
sched_mode_t mode = convert_policy_to_sched_mode(policy);
assert(thread->static_param);
if (!thread->static_param)
return KERN_FAILURE;
/* Concern: this doesn't hold the mutex... */
if (!thread->active)
return KERN_TERMINATED;
kern_return_t kr = thread_set_mode_and_absolute_pri_internal(thread, mode, priority, &pend_token);
if (pend_token.tpt_update_thread_sfi)
sfi_reevaluate(thread);
return kr;
}
/*
* thread_set_mode_and_absolute_pri:
*
* Set scheduling policy & absolute priority for thread, for deprecated
* thread_set_policy and thread_policy interfaces.
*
* Called with nothing locked.
*/
kern_return_t
thread_set_mode_and_absolute_pri(thread_t thread,
integer_t policy,
integer_t priority)
{
kern_return_t kr = KERN_SUCCESS;
struct task_pend_token pend_token = {};
sched_mode_t mode = convert_policy_to_sched_mode(policy);
thread_mtx_lock(thread);
if (!thread->active) {
kr = KERN_TERMINATED;
goto unlock;
}
if (thread_is_static_param(thread)) {
kr = KERN_POLICY_STATIC;
goto unlock;
}
/* Setting legacy policies on threads kills the current QoS */
if (thread->requested_policy.thrp_qos != THREAD_QOS_UNSPECIFIED)
thread_remove_qos_policy_locked(thread, &pend_token);
kr = thread_set_mode_and_absolute_pri_internal(thread, mode, priority, &pend_token);
unlock:
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
return (kr);
}
/*
* Set the thread's requested mode and recompute priority
* Called with thread mutex and thread locked
*
* TODO: Mitigate potential problems caused by moving thread to end of runq
* whenever its priority is recomputed
* Only remove when it actually changes? Attempt to re-insert at appropriate location?
*/
static void
thread_set_user_sched_mode_and_recompute_pri(thread_t thread, sched_mode_t mode)
{
if (thread->policy_reset)
return;
boolean_t removed = thread_run_queue_remove(thread);
/*
* TODO: Instead of having saved mode, have 'user mode' and 'true mode'.
* That way there's zero confusion over which the user wants
* and which the kernel wants.
*/
if (thread->sched_flags & TH_SFLAG_DEMOTED_MASK)
thread->saved_mode = mode;
else
sched_set_thread_mode(thread, mode);
thread_recompute_priority(thread);
if (removed)
thread_run_queue_reinsert(thread, SCHED_TAILQ);
}
/* called at splsched with thread lock locked */
static void
thread_update_qos_cpu_time_locked(thread_t thread)
{
task_t task = thread->task;
uint64_t timer_sum, timer_delta;
/*
* This is only as accurate as the distance between
* last context switch (embedded) or last user/kernel boundary transition (desktop)
* because user_timer and system_timer are only updated then.
*
* TODO: Consider running a thread_timer_event operation here to update it first.
* Maybe doable with interrupts disabled from current thread.
* If the thread is on a different core, may not be easy to get right.
*
* TODO: There should be a function for this in timer.c
*/
timer_sum = timer_grab(&thread->user_timer);
timer_sum += timer_grab(&thread->system_timer);
timer_delta = timer_sum - thread->vtimer_qos_save;
thread->vtimer_qos_save = timer_sum;
uint64_t* task_counter = NULL;
/* Update the task-level qos stats atomically, because we don't have the task lock. */
switch (thread->effective_policy.thep_qos) {
case THREAD_QOS_DEFAULT: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_default; break;
case THREAD_QOS_MAINTENANCE: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_maintenance; break;
case THREAD_QOS_BACKGROUND: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_background; break;
case THREAD_QOS_UTILITY: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_utility; break;
case THREAD_QOS_LEGACY: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_legacy; break;
case THREAD_QOS_USER_INITIATED: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_user_initiated; break;
case THREAD_QOS_USER_INTERACTIVE: task_counter = &task->cpu_time_qos_stats.cpu_time_qos_user_interactive; break;
default:
panic("unknown effective QoS: %d", thread->effective_policy.thep_qos);
}
OSAddAtomic64(timer_delta, task_counter);
}
/*
* called with no thread locks held
* may hold task lock
*/
void
thread_update_qos_cpu_time(thread_t thread)
{
thread_mtx_lock(thread);
spl_t s = splsched();
thread_lock(thread);
thread_update_qos_cpu_time_locked(thread);
thread_unlock(thread);
splx(s);
thread_mtx_unlock(thread);
}
/*
* Calculate base priority from thread attributes, and set it on the thread
*
* Called with thread_lock and thread mutex held.
*/
void
thread_recompute_priority(
thread_t thread)
{
integer_t priority;
if (thread->policy_reset)
return;
if (thread->sched_mode == TH_MODE_REALTIME) {
sched_set_thread_base_priority(thread, BASEPRI_RTQUEUES);
return;
} else if (thread->effective_policy.thep_qos != THREAD_QOS_UNSPECIFIED) {
int qos = thread->effective_policy.thep_qos;
int qos_ui_is_urgent = thread->effective_policy.thep_qos_ui_is_urgent;
int qos_relprio = -(thread->effective_policy.thep_qos_relprio); /* stored in task policy inverted */
int qos_scaled_relprio;
assert(qos >= 0 && qos < THREAD_QOS_LAST);
assert(qos_relprio <= 0 && qos_relprio >= THREAD_QOS_MIN_TIER_IMPORTANCE);
priority = thread_qos_policy_params.qos_pri[qos];
qos_scaled_relprio = thread_qos_scaled_relative_priority(qos, qos_relprio);
if (qos == THREAD_QOS_USER_INTERACTIVE && qos_ui_is_urgent == 1) {
/* Bump priority 46 to 47 when in a frontmost app */
qos_scaled_relprio += 1;
}
/* TODO: factor in renice priority here? */
priority += qos_scaled_relprio;
} else {
if (thread->importance > MAXPRI)
priority = MAXPRI;
else if (thread->importance < -MAXPRI)
priority = -MAXPRI;
else
priority = thread->importance;
priority += thread->task_priority;
}
priority = MAX(priority, thread->user_promotion_basepri);
/*
* Clamp priority back into the allowed range for this task.
* The initial priority value could be out of this range due to:
* Task clamped to BG or Utility (max-pri is 4, or 20)
* Task is user task (max-pri is 63)
* Task is kernel task (max-pri is 95)
* Note that thread->importance is user-settable to any integer
* via THREAD_PRECEDENCE_POLICY.
*/
if (priority > thread->max_priority)
priority = thread->max_priority;
else if (priority < MINPRI)
priority = MINPRI;
if (thread->saved_mode == TH_MODE_REALTIME &&
thread->sched_flags & TH_SFLAG_FAILSAFE)
priority = DEPRESSPRI;
if (thread->effective_policy.thep_terminated == TRUE) {
/*
* We temporarily want to override the expected priority to
* ensure that the thread exits in a timely manner.
* Note that this is allowed to exceed thread->max_priority
* so that the thread is no longer clamped to background
* during the final exit phase.
*/
if (priority < thread->task_priority)
priority = thread->task_priority;
if (priority < BASEPRI_DEFAULT)
priority = BASEPRI_DEFAULT;
}
#if CONFIG_EMBEDDED
/* No one can have a base priority less than MAXPRI_THROTTLE */
if (priority < MAXPRI_THROTTLE)
priority = MAXPRI_THROTTLE;
#endif /* CONFIG_EMBEDDED */
sched_set_thread_base_priority(thread, priority);
}
/* Called with the task lock held, but not the thread mutex or spinlock */
void
thread_policy_update_tasklocked(
thread_t thread,
integer_t priority,
integer_t max_priority,
task_pend_token_t pend_token)
{
thread_mtx_lock(thread);
if (!thread->active || thread->policy_reset) {
thread_mtx_unlock(thread);
return;
}
spl_t s = splsched();
thread_lock(thread);
__unused
integer_t old_max_priority = thread->max_priority;
thread->task_priority = priority;
thread->max_priority = max_priority;
#if CONFIG_EMBEDDED
/*
* When backgrounding a thread, iOS has the semantic that
* realtime and fixed priority threads should be demoted
* to timeshare background threads.
*
* On OSX, realtime and fixed priority threads don't lose their mode.
*
* TODO: Do this inside the thread policy update routine in order to avoid double
* remove/reinsert for a runnable thread
*/
if ((max_priority <= MAXPRI_THROTTLE) && (old_max_priority > MAXPRI_THROTTLE)) {
sched_thread_mode_demote(thread, TH_SFLAG_THROTTLED);
} else if ((max_priority > MAXPRI_THROTTLE) && (old_max_priority <= MAXPRI_THROTTLE)) {
sched_thread_mode_undemote(thread, TH_SFLAG_THROTTLED);
}
#endif /* CONFIG_EMBEDDED */
thread_policy_update_spinlocked(thread, TRUE, pend_token);
thread_unlock(thread);
splx(s);
thread_mtx_unlock(thread);
}
/*
* Reset thread to default state in preparation for termination
* Called with thread mutex locked
*
* Always called on current thread, so we don't need a run queue remove
*/
void
thread_policy_reset(
thread_t thread)
{
spl_t s;
assert(thread == current_thread());
s = splsched();
thread_lock(thread);
if (thread->sched_flags & TH_SFLAG_FAILSAFE)
sched_thread_mode_undemote(thread, TH_SFLAG_FAILSAFE);
if (thread->sched_flags & TH_SFLAG_THROTTLED)
sched_thread_mode_undemote(thread, TH_SFLAG_THROTTLED);
/* At this point, the various demotions should be inactive */
assert(!(thread->sched_flags & TH_SFLAG_DEMOTED_MASK));
assert(!(thread->sched_flags & TH_SFLAG_THROTTLED));
assert(!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK));
/* Reset thread back to task-default basepri and mode */
sched_mode_t newmode = SCHED(initial_thread_sched_mode)(thread->task);
sched_set_thread_mode(thread, newmode);
thread->importance = 0;
/* Prevent further changes to thread base priority or mode */
thread->policy_reset = 1;
sched_set_thread_base_priority(thread, thread->task_priority);
thread_unlock(thread);
splx(s);
}
kern_return_t
thread_policy_get(
thread_t thread,
thread_policy_flavor_t flavor,
thread_policy_t policy_info,
mach_msg_type_number_t *count,
boolean_t *get_default)
{
kern_return_t result = KERN_SUCCESS;
if (thread == THREAD_NULL)
return (KERN_INVALID_ARGUMENT);
thread_mtx_lock(thread);
if (!thread->active) {
thread_mtx_unlock(thread);
return (KERN_TERMINATED);
}
switch (flavor) {
case THREAD_EXTENDED_POLICY:
{
boolean_t timeshare = TRUE;
if (!(*get_default)) {
spl_t s = splsched();
thread_lock(thread);
if ( (thread->sched_mode != TH_MODE_REALTIME) &&
(thread->saved_mode != TH_MODE_REALTIME) ) {
if (!(thread->sched_flags & TH_SFLAG_DEMOTED_MASK))
timeshare = (thread->sched_mode == TH_MODE_TIMESHARE) != 0;
else
timeshare = (thread->saved_mode == TH_MODE_TIMESHARE) != 0;
}
else
*get_default = TRUE;
thread_unlock(thread);
splx(s);
}
if (*count >= THREAD_EXTENDED_POLICY_COUNT) {
thread_extended_policy_t info;
info = (thread_extended_policy_t)policy_info;
info->timeshare = timeshare;
}
break;
}
case THREAD_TIME_CONSTRAINT_POLICY:
{
thread_time_constraint_policy_t info;
if (*count < THREAD_TIME_CONSTRAINT_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_time_constraint_policy_t)policy_info;
if (!(*get_default)) {
spl_t s = splsched();
thread_lock(thread);
if ( (thread->sched_mode == TH_MODE_REALTIME) ||
(thread->saved_mode == TH_MODE_REALTIME) ) {
info->period = thread->realtime.period;
info->computation = thread->realtime.computation;
info->constraint = thread->realtime.constraint;
info->preemptible = thread->realtime.preemptible;
}
else
*get_default = TRUE;
thread_unlock(thread);
splx(s);
}
if (*get_default) {
info->period = 0;
info->computation = default_timeshare_computation;
info->constraint = default_timeshare_constraint;
info->preemptible = TRUE;
}
break;
}
case THREAD_PRECEDENCE_POLICY:
{
thread_precedence_policy_t info;
if (*count < THREAD_PRECEDENCE_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_precedence_policy_t)policy_info;
if (!(*get_default)) {
spl_t s = splsched();
thread_lock(thread);
info->importance = thread->importance;
thread_unlock(thread);
splx(s);
}
else
info->importance = 0;
break;
}
case THREAD_AFFINITY_POLICY:
{
thread_affinity_policy_t info;
if (!thread_affinity_is_supported()) {
result = KERN_NOT_SUPPORTED;
break;
}
if (*count < THREAD_AFFINITY_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
info = (thread_affinity_policy_t)policy_info;
if (!(*get_default))
info->affinity_tag = thread_affinity_get(thread);
else
info->affinity_tag = THREAD_AFFINITY_TAG_NULL;
break;
}
case THREAD_POLICY_STATE:
{
thread_policy_state_t info;
if (*count < THREAD_POLICY_STATE_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
/* Only root can get this info */
if (current_task()->sec_token.val[0] != 0) {
result = KERN_PROTECTION_FAILURE;
break;
}
info = (thread_policy_state_t)(void*)policy_info;
if (!(*get_default)) {
info->flags = 0;
spl_t s = splsched();
thread_lock(thread);
info->flags |= (thread->static_param ? THREAD_POLICY_STATE_FLAG_STATIC_PARAM : 0);
info->thps_requested_policy = *(uint64_t*)(void*)(&thread->requested_policy);
info->thps_effective_policy = *(uint64_t*)(void*)(&thread->effective_policy);
info->thps_user_promotions = thread->user_promotions;
info->thps_user_promotion_basepri = thread->user_promotion_basepri;
info->thps_ipc_overrides = thread->ipc_overrides;
proc_get_thread_policy_bitfield(thread, info);
thread_unlock(thread);
splx(s);
} else {
info->requested = 0;
info->effective = 0;
info->pending = 0;
}
break;
}
case THREAD_LATENCY_QOS_POLICY:
{
thread_latency_qos_policy_t info = (thread_latency_qos_policy_t) policy_info;
thread_latency_qos_t plqos;
if (*count < THREAD_LATENCY_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (*get_default) {
plqos = 0;
} else {
plqos = proc_get_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_LATENCY_QOS, NULL);
}
info->thread_latency_qos_tier = qos_latency_policy_package(plqos);
}
break;
case THREAD_THROUGHPUT_QOS_POLICY:
{
thread_throughput_qos_policy_t info = (thread_throughput_qos_policy_t) policy_info;
thread_throughput_qos_t ptqos;
if (*count < THREAD_THROUGHPUT_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (*get_default) {
ptqos = 0;
} else {
ptqos = proc_get_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_THROUGH_QOS, NULL);
}
info->thread_throughput_qos_tier = qos_throughput_policy_package(ptqos);
}
break;
case THREAD_QOS_POLICY:
{
thread_qos_policy_t info = (thread_qos_policy_t)policy_info;
if (*count < THREAD_QOS_POLICY_COUNT) {
result = KERN_INVALID_ARGUMENT;
break;
}
if (!(*get_default)) {
int relprio_value = 0;
info->qos_tier = proc_get_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_AND_RELPRIO, &relprio_value);
info->tier_importance = -relprio_value;
} else {
info->qos_tier = THREAD_QOS_UNSPECIFIED;
info->tier_importance = 0;
}
break;
}
default:
result = KERN_INVALID_ARGUMENT;
break;
}
thread_mtx_unlock(thread);
return (result);
}
void
thread_policy_create(thread_t thread)
{
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_UPDATE, (IMP_UPDATE_TASK_CREATE | TASK_POLICY_THREAD))) | DBG_FUNC_START,
thread_tid(thread), theffective_0(thread),
theffective_1(thread), thread->base_pri, 0);
/* We pass a pend token but ignore it */
struct task_pend_token pend_token = {};
thread_policy_update_internal_spinlocked(thread, TRUE, &pend_token);
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_UPDATE, (IMP_UPDATE_TASK_CREATE | TASK_POLICY_THREAD))) | DBG_FUNC_END,
thread_tid(thread), theffective_0(thread),
theffective_1(thread), thread->base_pri, 0);
}
static void
thread_policy_update_spinlocked(thread_t thread, boolean_t recompute_priority, task_pend_token_t pend_token)
{
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_UPDATE, TASK_POLICY_THREAD) | DBG_FUNC_START),
thread_tid(thread), theffective_0(thread),
theffective_1(thread), thread->base_pri, 0);
thread_policy_update_internal_spinlocked(thread, recompute_priority, pend_token);
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_UPDATE, TASK_POLICY_THREAD)) | DBG_FUNC_END,
thread_tid(thread), theffective_0(thread),
theffective_1(thread), thread->base_pri, 0);
}
/*
* One thread state update function TO RULE THEM ALL
*
* This function updates the thread effective policy fields
* and pushes the results to the relevant subsystems.
*
* Returns TRUE if a pended action needs to be run.
*
* Called with thread spinlock locked, task may be locked, thread mutex may be locked
*/
static void
thread_policy_update_internal_spinlocked(thread_t thread, boolean_t recompute_priority,
task_pend_token_t pend_token)
{
/*
* Step 1:
* Gather requested policy and effective task state
*/
struct thread_requested_policy requested = thread->requested_policy;
struct task_effective_policy task_effective = thread->task->effective_policy;
/*
* Step 2:
* Calculate new effective policies from requested policy, task and thread state
* Rules:
* Don't change requested, it won't take effect
*/
struct thread_effective_policy next = {};
next.thep_qos_ui_is_urgent = task_effective.tep_qos_ui_is_urgent;
uint32_t next_qos = requested.thrp_qos;
if (requested.thrp_qos != THREAD_QOS_UNSPECIFIED) {
if (requested.thrp_qos_override != THREAD_QOS_UNSPECIFIED)
next_qos = MAX(requested.thrp_qos_override, next_qos);
if (requested.thrp_qos_promote != THREAD_QOS_UNSPECIFIED)
next_qos = MAX(requested.thrp_qos_promote, next_qos);
if (requested.thrp_qos_ipc_override != THREAD_QOS_UNSPECIFIED)
next_qos = MAX(requested.thrp_qos_ipc_override, next_qos);
}
next.thep_qos = next_qos;
/* A task clamp will result in an effective QoS even when requested is UNSPECIFIED */
if (task_effective.tep_qos_clamp != THREAD_QOS_UNSPECIFIED) {
if (next.thep_qos != THREAD_QOS_UNSPECIFIED)
next.thep_qos = MIN(task_effective.tep_qos_clamp, next.thep_qos);
else
next.thep_qos = task_effective.tep_qos_clamp;
}
/*
* Extract outbound-promotion QoS before applying task ceiling or BG clamp
* This allows QoS promotions to work properly even after the process is unclamped.
*/
next.thep_qos_promote = next.thep_qos;
/* The ceiling only applies to threads that are in the QoS world */
if (task_effective.tep_qos_ceiling != THREAD_QOS_UNSPECIFIED &&
next.thep_qos != THREAD_QOS_UNSPECIFIED) {
next.thep_qos = MIN(task_effective.tep_qos_ceiling, next.thep_qos);
}
/* Apply the sync ipc qos override */
if (requested.thrp_qos_sync_ipc_override != THREAD_QOS_UNSPECIFIED)
next.thep_qos = MAX(requested.thrp_qos_sync_ipc_override, next.thep_qos);
/*
* The QoS relative priority is only applicable when the original programmer's
* intended (requested) QoS is in effect. When the QoS is clamped (e.g.
* USER_INITIATED-13REL clamped to UTILITY), the relative priority is not honored,
* since otherwise it would be lower than unclamped threads. Similarly, in the
* presence of boosting, the programmer doesn't know what other actors
* are boosting the thread.
*/
if ((requested.thrp_qos != THREAD_QOS_UNSPECIFIED) &&
(requested.thrp_qos == next.thep_qos) &&
(requested.thrp_qos_override == THREAD_QOS_UNSPECIFIED)) {
next.thep_qos_relprio = requested.thrp_qos_relprio;
} else {
next.thep_qos_relprio = 0;
}
/* Calculate DARWIN_BG */
boolean_t wants_darwinbg = FALSE;
boolean_t wants_all_sockets_bg = FALSE; /* Do I want my existing sockets to be bg */
/*
* If DARWIN_BG has been requested at either level, it's engaged.
* darwinbg threads always create bg sockets,
* but only some types of darwinbg change the sockets
* after they're created
*/
if (requested.thrp_int_darwinbg || requested.thrp_ext_darwinbg)
wants_all_sockets_bg = wants_darwinbg = TRUE;
if (requested.thrp_pidbind_bg)
wants_all_sockets_bg = wants_darwinbg = TRUE;
if (task_effective.tep_darwinbg)
wants_darwinbg = TRUE;
if (next.thep_qos == THREAD_QOS_BACKGROUND ||
next.thep_qos == THREAD_QOS_MAINTENANCE)
wants_darwinbg = TRUE;
/* Calculate side effects of DARWIN_BG */
if (wants_darwinbg)
next.thep_darwinbg = 1;
if (next.thep_darwinbg || task_effective.tep_new_sockets_bg)
next.thep_new_sockets_bg = 1;
/* Don't use task_effective.tep_all_sockets_bg here */
if (wants_all_sockets_bg)
next.thep_all_sockets_bg = 1;
/* darwinbg implies background QOS (or lower) */
if (next.thep_darwinbg &&
(next.thep_qos > THREAD_QOS_BACKGROUND || next.thep_qos == THREAD_QOS_UNSPECIFIED)) {
next.thep_qos = THREAD_QOS_BACKGROUND;
next.thep_qos_relprio = 0;
}
/* Calculate IO policy */
int iopol = THROTTLE_LEVEL_TIER0;
/* Factor in the task's IO policy */
if (next.thep_darwinbg)
iopol = MAX(iopol, task_effective.tep_bg_iotier);
iopol = MAX(iopol, task_effective.tep_io_tier);
/* Look up the associated IO tier value for the QoS class */
iopol = MAX(iopol, thread_qos_policy_params.qos_iotier[next.thep_qos]);
iopol = MAX(iopol, requested.thrp_int_iotier);
iopol = MAX(iopol, requested.thrp_ext_iotier);
next.thep_io_tier = iopol;
/*
* If a QoS override is causing IO to go into a lower tier, we also set
* the passive bit so that a thread doesn't end up stuck in its own throttle
* window when the override goes away.
*/
boolean_t qos_io_override_active = FALSE;
if (thread_qos_policy_params.qos_iotier[next.thep_qos] <
thread_qos_policy_params.qos_iotier[requested.thrp_qos])
qos_io_override_active = TRUE;
/* Calculate Passive IO policy */
if (requested.thrp_ext_iopassive ||
requested.thrp_int_iopassive ||
qos_io_override_active ||
task_effective.tep_io_passive )
next.thep_io_passive = 1;
/* Calculate timer QOS */
uint32_t latency_qos = requested.thrp_latency_qos;
latency_qos = MAX(latency_qos, task_effective.tep_latency_qos);
latency_qos = MAX(latency_qos, thread_qos_policy_params.qos_latency_qos[next.thep_qos]);
next.thep_latency_qos = latency_qos;
/* Calculate throughput QOS */
uint32_t through_qos = requested.thrp_through_qos;
through_qos = MAX(through_qos, task_effective.tep_through_qos);
through_qos = MAX(through_qos, thread_qos_policy_params.qos_through_qos[next.thep_qos]);
next.thep_through_qos = through_qos;
if (task_effective.tep_terminated || requested.thrp_terminated) {
/* Shoot down the throttles that slow down exit or response to SIGTERM */
next.thep_terminated = 1;
next.thep_darwinbg = 0;
next.thep_io_tier = THROTTLE_LEVEL_TIER0;
next.thep_qos = THREAD_QOS_UNSPECIFIED;
next.thep_latency_qos = LATENCY_QOS_TIER_UNSPECIFIED;
next.thep_through_qos = THROUGHPUT_QOS_TIER_UNSPECIFIED;
}
/*
* Step 3:
* Swap out old policy for new policy
*/
struct thread_effective_policy prev = thread->effective_policy;
thread_update_qos_cpu_time_locked(thread);
/* This is the point where the new values become visible to other threads */
thread->effective_policy = next;
/*
* Step 4:
* Pend updates that can't be done while holding the thread lock
*/
if (prev.thep_all_sockets_bg != next.thep_all_sockets_bg)
pend_token->tpt_update_sockets = 1;
/* TODO: Doesn't this only need to be done if the throttle went up? */
if (prev.thep_io_tier != next.thep_io_tier)
pend_token->tpt_update_throttle = 1;
/*
* Check for the attributes that sfi_thread_classify() consults,
* and trigger SFI re-evaluation.
*/
if (prev.thep_qos != next.thep_qos ||
prev.thep_darwinbg != next.thep_darwinbg )
pend_token->tpt_update_thread_sfi = 1;
/*
* Step 5:
* Update other subsystems as necessary if something has changed
*/
/* Check for the attributes that thread_recompute_priority() consults */
if (prev.thep_qos != next.thep_qos ||
prev.thep_qos_relprio != next.thep_qos_relprio ||
prev.thep_qos_ui_is_urgent != next.thep_qos_ui_is_urgent ||
prev.thep_terminated != next.thep_terminated ||
pend_token->tpt_force_recompute_pri == 1 ||
recompute_priority) {
thread_recompute_priority(thread);
}
}
/*
* Initiate a thread policy state transition on a thread with its TID
* Useful if you cannot guarantee the thread won't get terminated
* Precondition: No locks are held
* Will take task lock - using the non-tid variant is faster
* if you already have a thread ref.
*/
void
proc_set_thread_policy_with_tid(task_t task,
uint64_t tid,
int category,
int flavor,
int value)
{
/* takes task lock, returns ref'ed thread or NULL */
thread_t thread = task_findtid(task, tid);
if (thread == THREAD_NULL)
return;
proc_set_thread_policy(thread, category, flavor, value);
thread_deallocate(thread);
}
/*
* Initiate a thread policy transition on a thread
* This path supports networking transitions (i.e. darwinbg transitions)
* Precondition: No locks are held
*/
void
proc_set_thread_policy(thread_t thread,
int category,
int flavor,
int value)
{
struct task_pend_token pend_token = {};
thread_mtx_lock(thread);
proc_set_thread_policy_locked(thread, category, flavor, value, 0, &pend_token);
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
}
/*
* KPI for pthread kext to call to set thread base QoS values during a workq wakeup
* May be called with interrupts disabled and workqueue/waitqueue/kqueue locks held
*
* Does NOT do update completion, so the thread MUST be in a safe place WRT
* IO throttling and SFI.
*
* TODO: Can I assert 'it must be in a safe place'?
*/
kern_return_t
thread_set_workq_qos(thread_t thread,
int qos_tier,
int relprio) /* relprio is -16 to 0 */
{
assert(qos_tier >= 0 && qos_tier <= THREAD_QOS_LAST);
assert(relprio <= 0 && relprio >= THREAD_QOS_MIN_TIER_IMPORTANCE);
if (!(qos_tier >= 0 && qos_tier <= THREAD_QOS_LAST))
return KERN_FAILURE;
if (!(relprio <= 0 && relprio >= THREAD_QOS_MIN_TIER_IMPORTANCE))
return KERN_FAILURE;
if (qos_tier == THREAD_QOS_UNSPECIFIED) {
assert(relprio == 0);
if (relprio != 0)
return KERN_FAILURE;
}
assert(thread->static_param);
if (!thread->static_param) {
return KERN_FAILURE;
}
/* Concern: this doesn't hold the mutex... */
//if (!thread->active)
// return KERN_TERMINATED;
struct task_pend_token pend_token = {};
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_AND_RELPRIO, qos_tier, -relprio, &pend_token);
assert(pend_token.tpt_update_sockets == 0);
/* we don't need to update throttle or sfi because pthread kext promises the thread is in a safe place */
/* TODO: Do we need to update SFI to ensure it gets tagged with the AST? */
return KERN_SUCCESS;
}
/*
* Do the things that can't be done while holding a thread mutex.
* These are set up to call back into thread policy to get the latest value,
* so they don't have to be synchronized with the update.
* The only required semantic is 'call this sometime after updating effective policy'
*
* Precondition: Thread mutex is not held
*
* This may be called with the task lock held, but in that case it won't be
* called with tpt_update_sockets set.
*/
void
thread_policy_update_complete_unlocked(thread_t thread, task_pend_token_t pend_token)
{
#ifdef MACH_BSD
if (pend_token->tpt_update_sockets)
proc_apply_task_networkbg(thread->task->bsd_info, thread);
#endif /* MACH_BSD */
if (pend_token->tpt_update_throttle)
rethrottle_thread(thread->uthread);
if (pend_token->tpt_update_thread_sfi)
sfi_reevaluate(thread);
}
/*
* Set and update thread policy
* Thread mutex might be held
*/
static void
proc_set_thread_policy_locked(thread_t thread,
int category,
int flavor,
int value,
int value2,
task_pend_token_t pend_token)
{
spl_t s = splsched();
thread_lock(thread);
proc_set_thread_policy_spinlocked(thread, category, flavor, value, value2, pend_token);
thread_unlock(thread);
splx(s);
}
/*
* Set and update thread policy
* Thread spinlock is held
*/
static void
proc_set_thread_policy_spinlocked(thread_t thread,
int category,
int flavor,
int value,
int value2,
task_pend_token_t pend_token)
{
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(flavor, (category | TASK_POLICY_THREAD))) | DBG_FUNC_START,
thread_tid(thread), threquested_0(thread),
threquested_1(thread), value, 0);
thread_set_requested_policy_spinlocked(thread, category, flavor, value, value2);
thread_policy_update_spinlocked(thread, FALSE, pend_token);
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(flavor, (category | TASK_POLICY_THREAD))) | DBG_FUNC_END,
thread_tid(thread), threquested_0(thread),
threquested_1(thread), tpending(pend_token), 0);
}
/*
* Set the requested state for a specific flavor to a specific value.
*/
static void
thread_set_requested_policy_spinlocked(thread_t thread,
int category,
int flavor,
int value,
int value2)
{
int tier, passive;
struct thread_requested_policy requested = thread->requested_policy;
switch (flavor) {
/* Category: EXTERNAL and INTERNAL, thread and task */
case TASK_POLICY_DARWIN_BG:
if (category == TASK_POLICY_EXTERNAL)
requested.thrp_ext_darwinbg = value;
else
requested.thrp_int_darwinbg = value;
break;
case TASK_POLICY_IOPOL:
proc_iopol_to_tier(value, &tier, &passive);
if (category == TASK_POLICY_EXTERNAL) {
requested.thrp_ext_iotier = tier;
requested.thrp_ext_iopassive = passive;
} else {
requested.thrp_int_iotier = tier;
requested.thrp_int_iopassive = passive;
}
break;
case TASK_POLICY_IO:
if (category == TASK_POLICY_EXTERNAL)
requested.thrp_ext_iotier = value;
else
requested.thrp_int_iotier = value;
break;
case TASK_POLICY_PASSIVE_IO:
if (category == TASK_POLICY_EXTERNAL)
requested.thrp_ext_iopassive = value;
else
requested.thrp_int_iopassive = value;
break;
/* Category: ATTRIBUTE, thread only */
case TASK_POLICY_PIDBIND_BG:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_pidbind_bg = value;
break;
case TASK_POLICY_LATENCY_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_latency_qos = value;
break;
case TASK_POLICY_THROUGH_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_through_qos = value;
break;
case TASK_POLICY_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos = value;
break;
case TASK_POLICY_QOS_OVERRIDE:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos_override = value;
break;
case TASK_POLICY_QOS_AND_RELPRIO:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos = value;
requested.thrp_qos_relprio = value2;
DTRACE_BOOST3(qos_set, uint64_t, thread->thread_id, int, requested.thrp_qos, int, requested.thrp_qos_relprio);
break;
case TASK_POLICY_QOS_PROMOTE:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos_promote = value;
break;
case TASK_POLICY_QOS_IPC_OVERRIDE:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos_ipc_override = value;
break;
case TASK_POLICY_QOS_SYNC_IPC_OVERRIDE:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_qos_sync_ipc_override = value;
break;
case TASK_POLICY_TERMINATED:
assert(category == TASK_POLICY_ATTRIBUTE);
requested.thrp_terminated = value;
break;
default:
panic("unknown task policy: %d %d %d", category, flavor, value);
break;
}
thread->requested_policy = requested;
}
/*
* Gets what you set. Effective values may be different.
* Precondition: No locks are held
*/
int
proc_get_thread_policy(thread_t thread,
int category,
int flavor)
{
int value = 0;
thread_mtx_lock(thread);
value = proc_get_thread_policy_locked(thread, category, flavor, NULL);
thread_mtx_unlock(thread);
return value;
}
static int
proc_get_thread_policy_locked(thread_t thread,
int category,
int flavor,
int* value2)
{
int value = 0;
spl_t s = splsched();
thread_lock(thread);
value = thread_get_requested_policy_spinlocked(thread, category, flavor, value2);
thread_unlock(thread);
splx(s);
return value;
}
/*
* Gets what you set. Effective values may be different.
*/
static int
thread_get_requested_policy_spinlocked(thread_t thread,
int category,
int flavor,
int* value2)
{
int value = 0;
struct thread_requested_policy requested = thread->requested_policy;
switch (flavor) {
case TASK_POLICY_DARWIN_BG:
if (category == TASK_POLICY_EXTERNAL)
value = requested.thrp_ext_darwinbg;
else
value = requested.thrp_int_darwinbg;
break;
case TASK_POLICY_IOPOL:
if (category == TASK_POLICY_EXTERNAL)
value = proc_tier_to_iopol(requested.thrp_ext_iotier,
requested.thrp_ext_iopassive);
else
value = proc_tier_to_iopol(requested.thrp_int_iotier,
requested.thrp_int_iopassive);
break;
case TASK_POLICY_IO:
if (category == TASK_POLICY_EXTERNAL)
value = requested.thrp_ext_iotier;
else
value = requested.thrp_int_iotier;
break;
case TASK_POLICY_PASSIVE_IO:
if (category == TASK_POLICY_EXTERNAL)
value = requested.thrp_ext_iopassive;
else
value = requested.thrp_int_iopassive;
break;
case TASK_POLICY_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_qos;
break;
case TASK_POLICY_QOS_OVERRIDE:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_qos_override;
break;
case TASK_POLICY_LATENCY_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_latency_qos;
break;
case TASK_POLICY_THROUGH_QOS:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_through_qos;
break;
case TASK_POLICY_QOS_AND_RELPRIO:
assert(category == TASK_POLICY_ATTRIBUTE);
assert(value2 != NULL);
value = requested.thrp_qos;
*value2 = requested.thrp_qos_relprio;
break;
case TASK_POLICY_QOS_PROMOTE:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_qos_promote;
break;
case TASK_POLICY_QOS_IPC_OVERRIDE:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_qos_ipc_override;
break;
case TASK_POLICY_TERMINATED:
assert(category == TASK_POLICY_ATTRIBUTE);
value = requested.thrp_terminated;
break;
default:
panic("unknown policy_flavor %d", flavor);
break;
}
return value;
}
/*
* Gets what is actually in effect, for subsystems which pull policy instead of receive updates.
*
* NOTE: This accessor does not take the task or thread lock.
* Notifications of state updates need to be externally synchronized with state queries.
* This routine *MUST* remain interrupt safe, as it is potentially invoked
* within the context of a timer interrupt.
*
* TODO: I think we can get away with architecting this such that we don't need to look at the task ever.
* Is that a good idea? Maybe it's best to avoid evaluate-all-the-threads updates.
* I don't think that cost is worth not having the right answer.
*/
int
proc_get_effective_thread_policy(thread_t thread,
int flavor)
{
int value = 0;
switch (flavor) {
case TASK_POLICY_DARWIN_BG:
/*
* This call is used within the timer layer, as well as
* prioritizing requests to the graphics system.
* It also informs SFI and originator-bg-state.
* Returns 1 for background mode, 0 for normal mode
*/
value = thread->effective_policy.thep_darwinbg ? 1 : 0;
break;
case TASK_POLICY_IO:
/*
* The I/O system calls here to find out what throttling tier to apply to an operation.
* Returns THROTTLE_LEVEL_* values
*/
value = thread->effective_policy.thep_io_tier;
if (thread->iotier_override != THROTTLE_LEVEL_NONE)
value = MIN(value, thread->iotier_override);
break;
case TASK_POLICY_PASSIVE_IO:
/*
* The I/O system calls here to find out whether an operation should be passive.
* (i.e. not cause operations with lower throttle tiers to be throttled)
* Returns 1 for passive mode, 0 for normal mode
*
* If an override is causing IO to go into a lower tier, we also set
* the passive bit so that a thread doesn't end up stuck in its own throttle
* window when the override goes away.
*/
value = thread->effective_policy.thep_io_passive ? 1 : 0;
if (thread->iotier_override != THROTTLE_LEVEL_NONE &&
thread->iotier_override < thread->effective_policy.thep_io_tier)
value = 1;
break;
case TASK_POLICY_ALL_SOCKETS_BG:
/*
* do_background_socket() calls this to determine whether
* it should change the thread's sockets
* Returns 1 for background mode, 0 for normal mode
* This consults both thread and task so un-DBGing a thread while the task is BG
* doesn't get you out of the network throttle.
*/
value = (thread->effective_policy.thep_all_sockets_bg ||
thread->task->effective_policy.tep_all_sockets_bg) ? 1 : 0;
break;
case TASK_POLICY_NEW_SOCKETS_BG:
/*
* socreate() calls this to determine if it should mark a new socket as background
* Returns 1 for background mode, 0 for normal mode
*/
value = thread->effective_policy.thep_new_sockets_bg ? 1 : 0;
break;
case TASK_POLICY_LATENCY_QOS:
/*
* timer arming calls into here to find out the timer coalescing level
* Returns a latency QoS tier (0-6)
*/
value = thread->effective_policy.thep_latency_qos;
break;
case TASK_POLICY_THROUGH_QOS:
/*
* This value is passed into the urgency callout from the scheduler
* to the performance management subsystem.
*
* Returns a throughput QoS tier (0-6)
*/
value = thread->effective_policy.thep_through_qos;
break;
case TASK_POLICY_QOS:
/*
* This is communicated to the performance management layer and SFI.
*
* Returns a QoS policy tier
*/
value = thread->effective_policy.thep_qos;
break;
default:
panic("unknown thread policy flavor %d", flavor);
break;
}
return value;
}
/*
* (integer_t) casts limit the number of bits we can fit here
* this interface is deprecated and replaced by the _EXT struct ?
*/
static void
proc_get_thread_policy_bitfield(thread_t thread, thread_policy_state_t info)
{
uint64_t bits = 0;
struct thread_requested_policy requested = thread->requested_policy;
bits |= (requested.thrp_int_darwinbg ? POLICY_REQ_INT_DARWIN_BG : 0);
bits |= (requested.thrp_ext_darwinbg ? POLICY_REQ_EXT_DARWIN_BG : 0);
bits |= (requested.thrp_int_iotier ? (((uint64_t)requested.thrp_int_iotier) << POLICY_REQ_INT_IO_TIER_SHIFT) : 0);
bits |= (requested.thrp_ext_iotier ? (((uint64_t)requested.thrp_ext_iotier) << POLICY_REQ_EXT_IO_TIER_SHIFT) : 0);
bits |= (requested.thrp_int_iopassive ? POLICY_REQ_INT_PASSIVE_IO : 0);
bits |= (requested.thrp_ext_iopassive ? POLICY_REQ_EXT_PASSIVE_IO : 0);
bits |= (requested.thrp_qos ? (((uint64_t)requested.thrp_qos) << POLICY_REQ_TH_QOS_SHIFT) : 0);
bits |= (requested.thrp_qos_override ? (((uint64_t)requested.thrp_qos_override) << POLICY_REQ_TH_QOS_OVER_SHIFT) : 0);
bits |= (requested.thrp_pidbind_bg ? POLICY_REQ_PIDBIND_BG : 0);
bits |= (requested.thrp_latency_qos ? (((uint64_t)requested.thrp_latency_qos) << POLICY_REQ_BASE_LATENCY_QOS_SHIFT) : 0);
bits |= (requested.thrp_through_qos ? (((uint64_t)requested.thrp_through_qos) << POLICY_REQ_BASE_THROUGH_QOS_SHIFT) : 0);
info->requested = (integer_t) bits;
bits = 0;
struct thread_effective_policy effective = thread->effective_policy;
bits |= (effective.thep_darwinbg ? POLICY_EFF_DARWIN_BG : 0);
bits |= (effective.thep_io_tier ? (((uint64_t)effective.thep_io_tier) << POLICY_EFF_IO_TIER_SHIFT) : 0);
bits |= (effective.thep_io_passive ? POLICY_EFF_IO_PASSIVE : 0);
bits |= (effective.thep_all_sockets_bg ? POLICY_EFF_ALL_SOCKETS_BG : 0);
bits |= (effective.thep_new_sockets_bg ? POLICY_EFF_NEW_SOCKETS_BG : 0);
bits |= (effective.thep_qos ? (((uint64_t)effective.thep_qos) << POLICY_EFF_TH_QOS_SHIFT) : 0);
bits |= (effective.thep_latency_qos ? (((uint64_t)effective.thep_latency_qos) << POLICY_EFF_LATENCY_QOS_SHIFT) : 0);
bits |= (effective.thep_through_qos ? (((uint64_t)effective.thep_through_qos) << POLICY_EFF_THROUGH_QOS_SHIFT) : 0);
info->effective = (integer_t)bits;
bits = 0;
info->pending = 0;
}
/*
* Sneakily trace either the task and thread requested
* or just the thread requested, depending on if we have enough room.
* We do have room on LP64. On LP32, we have to split it between two uintptr_t's.
*
* LP32 LP64
* threquested_0(thread) thread[0] task[0]
* threquested_1(thread) thread[1] thread[0]
*
*/
uintptr_t
threquested_0(thread_t thread)
{
static_assert(sizeof(struct thread_requested_policy) == sizeof(uint64_t), "size invariant violated");
uintptr_t* raw = (uintptr_t*)(void*)&thread->requested_policy;
return raw[0];
}
uintptr_t
threquested_1(thread_t thread)
{
#if defined __LP64__
return *(uintptr_t*)&thread->task->requested_policy;
#else
uintptr_t* raw = (uintptr_t*)(void*)&thread->requested_policy;
return raw[1];
#endif
}
uintptr_t
theffective_0(thread_t thread)
{
static_assert(sizeof(struct thread_effective_policy) == sizeof(uint64_t), "size invariant violated");
uintptr_t* raw = (uintptr_t*)(void*)&thread->effective_policy;
return raw[0];
}
uintptr_t
theffective_1(thread_t thread)
{
#if defined __LP64__
return *(uintptr_t*)&thread->task->effective_policy;
#else
uintptr_t* raw = (uintptr_t*)(void*)&thread->effective_policy;
return raw[1];
#endif
}
/*
* Set an override on the thread which is consulted with a
* higher priority than the task/thread policy. This should
* only be set for temporary grants until the thread
* returns to the userspace boundary
*
* We use atomic operations to swap in the override, with
* the assumption that the thread itself can
* read the override and clear it on return to userspace.
*
* No locking is performed, since it is acceptable to see
* a stale override for one loop through throttle_lowpri_io().
* However a thread reference must be held on the thread.
*/
void set_thread_iotier_override(thread_t thread, int policy)
{
int current_override;
/* Let most aggressive I/O policy win until user boundary */
do {
current_override = thread->iotier_override;
if (current_override != THROTTLE_LEVEL_NONE)
policy = MIN(current_override, policy);
if (current_override == policy) {
/* no effective change */
return;
}
} while (!OSCompareAndSwap(current_override, policy, &thread->iotier_override));
/*
* Since the thread may be currently throttled,
* re-evaluate tiers and potentially break out
* of an msleep
*/
rethrottle_thread(thread->uthread);
}
/*
* Userspace synchronization routines (like pthread mutexes, pthread reader-writer locks,
* semaphores, dispatch_sync) may result in priority inversions where a higher priority
* (i.e. scheduler priority, I/O tier, QoS tier) is waiting on a resource owned by a lower
* priority thread. In these cases, we attempt to propagate the priority token, as long
* as the subsystem informs us of the relationships between the threads. The userspace
* synchronization subsystem should maintain the information of owner->resource and
* resource->waiters itself.
*/
/*
* This helper canonicalizes the resource/resource_type given the current qos_override_mode
* in effect. Note that wildcards (THREAD_QOS_OVERRIDE_RESOURCE_WILDCARD) may need
* to be handled specially in the future, but for now it's fine to slam
* *resource to USER_ADDR_NULL even if it was previously a wildcard.
*/
static void canonicalize_resource_and_type(user_addr_t *resource, int *resource_type) {
if (qos_override_mode == QOS_OVERRIDE_MODE_OVERHANG_PEAK || qos_override_mode == QOS_OVERRIDE_MODE_IGNORE_OVERRIDE) {
/* Map all input resource/type to a single one */
*resource = USER_ADDR_NULL;
*resource_type = THREAD_QOS_OVERRIDE_TYPE_UNKNOWN;
} else if (qos_override_mode == QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE) {
/* no transform */
} else if (qos_override_mode == QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_IGNORE_DISPATCH) {
/* Map all dispatch overrides to a single one, to avoid memory overhead */
if (*resource_type == THREAD_QOS_OVERRIDE_TYPE_DISPATCH_ASYNCHRONOUS_OVERRIDE) {
*resource = USER_ADDR_NULL;
}
} else if (qos_override_mode == QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_SINGLE_MUTEX_OVERRIDE) {
/* Map all mutex overrides to a single one, to avoid memory overhead */
if (*resource_type == THREAD_QOS_OVERRIDE_TYPE_PTHREAD_MUTEX) {
*resource = USER_ADDR_NULL;
}
}
}
/* This helper routine finds an existing override if known. Locking should be done by caller */
static struct thread_qos_override *
find_qos_override(thread_t thread,
user_addr_t resource,
int resource_type)
{
struct thread_qos_override *override;
override = thread->overrides;
while (override) {
if (override->override_resource == resource &&
override->override_resource_type == resource_type) {
return override;
}
override = override->override_next;
}
return NULL;
}
static void
find_and_decrement_qos_override(thread_t thread,
user_addr_t resource,
int resource_type,
boolean_t reset,
struct thread_qos_override **free_override_list)
{
struct thread_qos_override *override, *override_prev;
override_prev = NULL;
override = thread->overrides;
while (override) {
struct thread_qos_override *override_next = override->override_next;
if ((THREAD_QOS_OVERRIDE_RESOURCE_WILDCARD == resource || override->override_resource == resource) &&
(THREAD_QOS_OVERRIDE_TYPE_WILDCARD == resource_type || override->override_resource_type == resource_type)) {
if (reset) {
override->override_contended_resource_count = 0;
} else {
override->override_contended_resource_count--;
}
if (override->override_contended_resource_count == 0) {
if (override_prev == NULL) {
thread->overrides = override_next;
} else {
override_prev->override_next = override_next;
}
/* Add to out-param for later zfree */
override->override_next = *free_override_list;
*free_override_list = override;
} else {
override_prev = override;
}
if (THREAD_QOS_OVERRIDE_RESOURCE_WILDCARD != resource) {
return;
}
} else {
override_prev = override;
}
override = override_next;
}
}
/* This helper recalculates the current requested override using the policy selected at boot */
static int
calculate_requested_qos_override(thread_t thread)
{
if (qos_override_mode == QOS_OVERRIDE_MODE_IGNORE_OVERRIDE) {
return THREAD_QOS_UNSPECIFIED;
}
/* iterate over all overrides and calculate MAX */
struct thread_qos_override *override;
int qos_override = THREAD_QOS_UNSPECIFIED;
override = thread->overrides;
while (override) {
if (qos_override_mode != QOS_OVERRIDE_MODE_FINE_GRAINED_OVERRIDE_BUT_IGNORE_DISPATCH ||
override->override_resource_type != THREAD_QOS_OVERRIDE_TYPE_DISPATCH_ASYNCHRONOUS_OVERRIDE) {
qos_override = MAX(qos_override, override->override_qos);
}
override = override->override_next;
}
return qos_override;
}
/*
* Returns:
* - 0 on success
* - EINVAL if some invalid input was passed
* - EFAULT if user_lock_addr != NULL and needs to be faulted (userland has to
* fault and retry)
* - ESTALE if user_lock_addr != NULL &&
* ulock_owner_value_to_port_name(*user_lock_addr) != user_lock_owner
*/
static int
proc_thread_qos_add_override_internal(thread_t thread,
int override_qos,
boolean_t first_override_for_resource,
user_addr_t resource,
int resource_type,
user_addr_t user_lock_addr,
mach_port_name_t user_lock_owner)
{
struct task_pend_token pend_token = {};
int rc = 0;
thread_mtx_lock(thread);
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_ADD_OVERRIDE)) | DBG_FUNC_START,
thread_tid(thread), override_qos, first_override_for_resource ? 1 : 0, 0, 0);
DTRACE_BOOST5(qos_add_override_pre, uint64_t, thread_tid(thread),
uint64_t, thread->requested_policy.thrp_qos,
uint64_t, thread->effective_policy.thep_qos,
int, override_qos, boolean_t, first_override_for_resource);
struct thread_qos_override *override;
struct thread_qos_override *override_new = NULL;
int new_qos_override, prev_qos_override;
int new_effective_qos;
canonicalize_resource_and_type(&resource, &resource_type);
override = find_qos_override(thread, resource, resource_type);
if (first_override_for_resource && !override) {
/* We need to allocate a new object. Drop the thread lock and
* recheck afterwards in case someone else added the override
*/
thread_mtx_unlock(thread);
override_new = zalloc(thread_qos_override_zone);
thread_mtx_lock(thread);
override = find_qos_override(thread, resource, resource_type);
}
if (user_lock_addr) {
uint64_t val;
/* Workaround lack of explicit support for 'no-fault copyin'
* <rdar://problem/24999882>, as disabling preemption prevents paging in
*/
disable_preemption();
rc = copyin_word(user_lock_addr, &val, sizeof(user_lock_owner));
enable_preemption();
if (rc == 0 && ulock_owner_value_to_port_name((uint32_t)val) != user_lock_owner) {
rc = ESTALE;
}
if (rc) {
prev_qos_override = proc_get_thread_policy_locked(thread,
TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_OVERRIDE, NULL);
new_qos_override = prev_qos_override;
new_effective_qos = proc_get_effective_thread_policy(thread, TASK_POLICY_QOS);
thread_mtx_unlock(thread);
goto out;
}
}
if (first_override_for_resource && override) {
/* Someone else already allocated while the thread lock was dropped */
override->override_contended_resource_count++;
} else if (!override && override_new) {
override = override_new;
override_new = NULL;
override->override_next = thread->overrides;
/* since first_override_for_resource was TRUE */
override->override_contended_resource_count = 1;
override->override_resource = resource;
override->override_resource_type = resource_type;
override->override_qos = THREAD_QOS_UNSPECIFIED;
thread->overrides = override;
}
if (override) {
if (override->override_qos == THREAD_QOS_UNSPECIFIED)
override->override_qos = override_qos;
else
override->override_qos = MAX(override->override_qos, override_qos);
}
/* Determine how to combine the various overrides into a single current
* requested override
*/
new_qos_override = calculate_requested_qos_override(thread);
prev_qos_override = proc_get_thread_policy_locked(thread,
TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_OVERRIDE, NULL);
if (new_qos_override != prev_qos_override) {
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_OVERRIDE,
new_qos_override, 0, &pend_token);
}
new_effective_qos = proc_get_effective_thread_policy(thread, TASK_POLICY_QOS);
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
out:
if (override_new) {
zfree(thread_qos_override_zone, override_new);
}
DTRACE_BOOST4(qos_add_override_post, int, prev_qos_override,
int, new_qos_override, int, new_effective_qos, int, rc);
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_ADD_OVERRIDE)) | DBG_FUNC_END,
new_qos_override, resource, resource_type, 0, 0);
return rc;
}
int
proc_thread_qos_add_override_check_owner(thread_t thread,
int override_qos,
boolean_t first_override_for_resource,
user_addr_t resource,
int resource_type,
user_addr_t user_lock_addr,
mach_port_name_t user_lock_owner)
{
return proc_thread_qos_add_override_internal(thread, override_qos,
first_override_for_resource, resource, resource_type,
user_lock_addr, user_lock_owner);
}
boolean_t
proc_thread_qos_add_override(task_t task,
thread_t thread,
uint64_t tid,
int override_qos,
boolean_t first_override_for_resource,
user_addr_t resource,
int resource_type)
{
boolean_t has_thread_reference = FALSE;
int rc = 0;
if (thread == THREAD_NULL) {
thread = task_findtid(task, tid);
/* returns referenced thread */
if (thread == THREAD_NULL) {
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_ADD_OVERRIDE)) | DBG_FUNC_NONE,
tid, 0, 0xdead, 0, 0);
return FALSE;
}
has_thread_reference = TRUE;
} else {
assert(thread->task == task);
}
rc = proc_thread_qos_add_override_internal(thread, override_qos,
first_override_for_resource, resource, resource_type, 0, 0);
if (has_thread_reference) {
thread_deallocate(thread);
}
return rc == 0;
}
static int
proc_thread_qos_remove_override_internal(thread_t thread,
user_addr_t resource,
int resource_type,
boolean_t reset,
boolean_t squash)
{
struct task_pend_token pend_token = {};
struct thread_qos_override *deferred_free_override_list = NULL;
int new_qos_override, prev_qos_override, new_effective_qos, prev_qos;
int new_qos = THREAD_QOS_UNSPECIFIED;
thread_mtx_lock(thread);
canonicalize_resource_and_type(&resource, &resource_type);
find_and_decrement_qos_override(thread, resource, resource_type, reset, &deferred_free_override_list);
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_REMOVE_OVERRIDE)) | DBG_FUNC_START,
thread_tid(thread), resource, reset, 0, 0);
DTRACE_BOOST3(qos_remove_override_pre, uint64_t, thread_tid(thread),
uint64_t, thread->requested_policy.thrp_qos,
uint64_t, thread->effective_policy.thep_qos);
/* Determine how to combine the various overrides into a single current requested override */
new_qos_override = calculate_requested_qos_override(thread);
spl_t s = splsched();
thread_lock(thread);
/*
* The override chain and therefore the value of the current override is locked with thread mutex,
* so we can do a get/set without races. However, the rest of thread policy is locked under the spinlock.
* This means you can't change the current override from a spinlock-only setter.
*/
prev_qos_override = thread_get_requested_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_OVERRIDE, NULL);
if (squash) {
int prev_ipc_override;
int prev_override;
/*
* Remove the specified overrides, and set the current override as the new base QoS.
* Return the new QoS value.
*/
prev_ipc_override = thread_get_requested_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_IPC_OVERRIDE, NULL);
prev_override = MAX(prev_qos_override, prev_ipc_override);
prev_qos = thread_get_requested_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS, NULL);
new_qos = MAX(prev_qos, prev_override);
if (new_qos != prev_qos)
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS, new_qos, 0, &pend_token);
}
if (new_qos_override != prev_qos_override)
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_OVERRIDE, new_qos_override, 0, &pend_token);
new_effective_qos = proc_get_effective_thread_policy(thread, TASK_POLICY_QOS);
thread_unlock(thread);
splx(s);
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
while (deferred_free_override_list) {
struct thread_qos_override *override_next = deferred_free_override_list->override_next;
zfree(thread_qos_override_zone, deferred_free_override_list);
deferred_free_override_list = override_next;
}
DTRACE_BOOST3(qos_remove_override_post, int, prev_qos_override,
int, new_qos_override, int, new_effective_qos);
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_REMOVE_OVERRIDE)) | DBG_FUNC_END,
thread_tid(thread), squash, 0, 0, 0);
return new_qos;
}
boolean_t
proc_thread_qos_remove_override(task_t task,
thread_t thread,
uint64_t tid,
user_addr_t resource,
int resource_type)
{
boolean_t has_thread_reference = FALSE;
if (thread == THREAD_NULL) {
thread = task_findtid(task, tid);
/* returns referenced thread */
if (thread == THREAD_NULL) {
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_REMOVE_OVERRIDE)) | DBG_FUNC_NONE,
tid, 0, 0xdead, 0, 0);
return FALSE;
}
has_thread_reference = TRUE;
} else {
assert(task == thread->task);
}
proc_thread_qos_remove_override_internal(thread, resource, resource_type, FALSE, FALSE);
if (has_thread_reference)
thread_deallocate(thread);
return TRUE;
}
boolean_t
proc_thread_qos_reset_override(task_t task,
thread_t thread,
uint64_t tid,
user_addr_t resource,
int resource_type)
{
boolean_t has_thread_reference = FALSE;
if (thread == THREAD_NULL) {
thread = task_findtid(task, tid);
/* returns referenced thread */
if (thread == THREAD_NULL) {
KERNEL_DEBUG_CONSTANT((IMPORTANCE_CODE(IMP_USYNCH_QOS_OVERRIDE, IMP_USYNCH_REMOVE_OVERRIDE)) | DBG_FUNC_NONE,
tid, 0, 0xdead, 0, 0);
return FALSE;
}
has_thread_reference = TRUE;
} else {
assert(task == thread->task);
}
proc_thread_qos_remove_override_internal(thread, resource, resource_type, TRUE, FALSE);
if (has_thread_reference)
thread_deallocate(thread);
return TRUE;
}
/*
* Clears the requested overrides, and replaces the current QoS with the max
* of the current QoS and the current override, then returns the new QoS.
*
* This is useful in order to reset overrides before parking a workqueue thread,
* but avoid dropping priority and getting preempted right before parking.
*
* Called without any locks held.
*/
int
proc_thread_qos_squash_override(thread_t thread, user_addr_t resource, int resource_type)
{
return proc_thread_qos_remove_override_internal(thread, resource, resource_type, TRUE, TRUE);
}
/* Deallocate before thread termination */
void proc_thread_qos_deallocate(thread_t thread)
{
/*
* There are no more references to this thread,
* therefore this thread must not own any more locks,
* therefore there must not be any more user promotions.
*/
assert(thread->user_promotions == 0);
assert(thread->requested_policy.thrp_qos_promote == THREAD_QOS_UNSPECIFIED);
assert(thread->user_promotion_basepri == 0);
/* This thread must have no more IPC overrides. */
assert(thread->ipc_overrides == 0);
assert(thread->requested_policy.thrp_qos_ipc_override == THREAD_QOS_UNSPECIFIED);
assert(thread->sync_ipc_overrides == 0);
assert(thread->requested_policy.thrp_qos_sync_ipc_override == THREAD_QOS_UNSPECIFIED);
/*
* Clear out any lingering override objects.
*/
struct thread_qos_override *override;
thread_mtx_lock(thread);
override = thread->overrides;
thread->overrides = NULL;
thread->requested_policy.thrp_qos_override = THREAD_QOS_UNSPECIFIED;
/* We don't need to re-evaluate thread policy here because the thread has already exited */
thread_mtx_unlock(thread);
while (override) {
struct thread_qos_override *override_next = override->override_next;
zfree(thread_qos_override_zone, override);
override = override_next;
}
}
/*
* Set up the primordial thread's QoS
*/
void
task_set_main_thread_qos(task_t task, thread_t thread) {
struct task_pend_token pend_token = {};
assert(thread->task == task);
thread_mtx_lock(thread);
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_MAIN_THREAD_QOS, 0)) | DBG_FUNC_START,
thread_tid(thread), threquested_0(thread), threquested_1(thread),
thread->requested_policy.thrp_qos, 0);
int primordial_qos = task_compute_main_thread_qos(task);
proc_set_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS,
primordial_qos, 0, &pend_token);
thread_mtx_unlock(thread);
thread_policy_update_complete_unlocked(thread, &pend_token);
KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE,
(IMPORTANCE_CODE(IMP_MAIN_THREAD_QOS, 0)) | DBG_FUNC_END,
thread_tid(thread), threquested_0(thread), threquested_1(thread),
primordial_qos, 0);
}
/*
* KPI for pthread kext
*
* Return a good guess at what the initial manager QoS will be
* Dispatch can override this in userspace if it so chooses
*/
int
task_get_default_manager_qos(task_t task)
{
int primordial_qos = task_compute_main_thread_qos(task);
if (primordial_qos == THREAD_QOS_LEGACY)
primordial_qos = THREAD_QOS_USER_INITIATED;
return primordial_qos;
}
/*
* Promote thread with the user level properties of 'promoter'
* Mutexes may be held, but it's OK to take the throttle lock
*
* if 'new_promotion' is TRUE, this is a new promotion.
* if FALSE, we are updating an existing promotion.
*/
static void
thread_user_promotion_promote(thread_t thread,
thread_t promoter,
struct promote_token* promote_token,
boolean_t new_promotion)
{
struct task_pend_token pend_token = {};
uint32_t promoter_base_pri = 0, promoter_qos = THREAD_QOS_UNSPECIFIED;
spl_t s = splsched();
thread_lock(promoter);
/*
* We capture the 'promotion qos' here, which is captured
* before task-level clamping.
*
* This means that if the process gets unclamped while a promotion,
* is in effect, the owning thread ends up with the correct QoS.
*
* This does NOT work correctly across processes, as the correct QoS
* in one is not necessarily the correct QoS in another.
* When we add support for multi-process ulock boosting, we need to
* do something more complex.
*/
promoter_qos = promoter->effective_policy.thep_qos_promote;
/* TODO: extract 'effective unclamped base pri' instead */
promoter_base_pri = promoter->base_pri;
thread_unlock(promoter);
splx(s);
/* clamp out realtime to max user pri */
promoter_base_pri = MIN(promoter_base_pri, MAXPRI_USER);
/* add in the saved promotion token */
assert(promote_token->pt_basepri <= MAXPRI_USER);
promoter_base_pri = MAX(promoter_base_pri, promote_token->pt_basepri);
promoter_qos = MAX(promoter_qos, promote_token->pt_qos);
/* save the max for later */
promote_token->pt_basepri = promoter_base_pri;
promote_token->pt_qos = promoter_qos;
s = splsched();
thread_lock(thread);
if (new_promotion) {
if (thread->user_promotions == 0) {
assert(thread->requested_policy.thrp_qos_promote == THREAD_QOS_UNSPECIFIED);
assert(thread->user_promotion_basepri == 0);
}
thread->user_promotions++;
} else {
assert(thread->user_promotions > 0);
}
uint32_t thread_qos = thread->requested_policy.thrp_qos_promote;
uint32_t thread_basepri = thread->user_promotion_basepri;
uint32_t new_qos = MAX(thread_qos, promoter_qos);
uint32_t new_basepri = MAX(thread_basepri, promoter_base_pri);
/* TODO: Fast path the 'new is lower than effective' case to avoid full reevaluation */
if (thread_qos != new_qos || thread_basepri != new_basepri) {
thread->user_promotion_basepri = new_basepri;
pend_token.tpt_force_recompute_pri = 1;
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_PROMOTE, new_qos,
0, &pend_token);
}
thread_unlock(thread);
splx(s);
thread_policy_update_complete_unlocked(thread, &pend_token);
}
/* Add a user promotion to thread */
void
thread_user_promotion_add(thread_t thread,
thread_t promoter,
struct promote_token* promote_token)
{
thread_user_promotion_promote(thread, promoter, promote_token, TRUE);
}
/* Update an existing user promotion on thread */
void
thread_user_promotion_update(thread_t thread,
thread_t promoter,
struct promote_token* promote_token)
{
thread_user_promotion_promote(thread, promoter, promote_token, FALSE);
}
/*
* Drop a user promotion on thread
* Mutexes may be held, but it's OK to take the throttle lock
*/
void
thread_user_promotion_drop(thread_t thread)
{
struct task_pend_token pend_token = {};
spl_t s = splsched();
thread_lock(thread);
assert(thread->user_promotions > 0);
if (--thread->user_promotions == 0) {
thread->requested_policy.thrp_qos_promote = THREAD_QOS_UNSPECIFIED;
thread->user_promotion_basepri = 0;
pend_token.tpt_force_recompute_pri = 1;
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_PROMOTE, THREAD_QOS_UNSPECIFIED,
0, &pend_token);
}
thread_unlock(thread);
splx(s);
thread_policy_update_complete_unlocked(thread, &pend_token);
}
/*
* Set the thread's QoS IPC override
* Owned by the IPC subsystem
*
* May be called with spinlocks held, but not spinlocks
* that may deadlock against the thread lock, the throttle lock, or the SFI lock.
*
* One 'add' must be balanced by one 'drop'.
* Between 'add' and 'drop', the overide QoS value may be updated with an 'update'.
* Before the thread is deallocated, there must be 0 remaining overrides.
*/
static void
thread_ipc_override(thread_t thread,
uint32_t qos_override,
boolean_t is_new_override)
{
struct task_pend_token pend_token = {};
boolean_t needs_update;
spl_t s = splsched();
thread_lock(thread);
uint32_t old_override = thread->requested_policy.thrp_qos_ipc_override;
assert(qos_override > THREAD_QOS_UNSPECIFIED);
assert(qos_override < THREAD_QOS_LAST);
if (is_new_override) {
if (thread->ipc_overrides++ == 0) {
/* This add is the first override for this thread */
assert(old_override == THREAD_QOS_UNSPECIFIED);
} else {
/* There are already other overrides in effect for this thread */
assert(old_override > THREAD_QOS_UNSPECIFIED);
}
} else {
/* There must be at least one override (the previous add call) in effect */
assert(thread->ipc_overrides > 0);
assert(old_override > THREAD_QOS_UNSPECIFIED);
}
/*
* We can't allow lowering if there are several IPC overrides because
* the caller can't possibly know the whole truth
*/
if (thread->ipc_overrides == 1) {
needs_update = qos_override != old_override;
} else {
needs_update = qos_override > old_override;
}
if (needs_update) {
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_IPC_OVERRIDE,
qos_override, 0, &pend_token);
assert(pend_token.tpt_update_sockets == 0);
}
thread_unlock(thread);
splx(s);
/*
* this is only safe after rethrottle_thread supports
* being called from spinlock context
*/
thread_policy_update_complete_unlocked(thread, &pend_token);
}
void
thread_add_ipc_override(thread_t thread,
uint32_t qos_override)
{
thread_ipc_override(thread, qos_override, TRUE);
}
void
thread_update_ipc_override(thread_t thread,
uint32_t qos_override)
{
thread_ipc_override(thread, qos_override, FALSE);
}
void
thread_drop_ipc_override(thread_t thread)
{
struct task_pend_token pend_token = {};
spl_t s = splsched();
thread_lock(thread);
assert(thread->ipc_overrides > 0);
if (--thread->ipc_overrides == 0) {
/*
* There are no more overrides for this thread, so we should
* clear out the saturated override value
*/
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_IPC_OVERRIDE, THREAD_QOS_UNSPECIFIED,
0, &pend_token);
}
thread_unlock(thread);
splx(s);
/*
* this is only safe after rethrottle_thread supports
* being called from spinlock context
*/
thread_policy_update_complete_unlocked(thread, &pend_token);
}
void
thread_add_sync_ipc_override(thread_t thread)
{
struct task_pend_token pend_token = {};
spl_t s = splsched();
thread_lock(thread);
uint32_t old_override __unused = thread->requested_policy.thrp_qos_sync_ipc_override;
if (thread->sync_ipc_overrides++ == 0) {
/* This add is the first override for this thread */
assert(old_override == THREAD_QOS_UNSPECIFIED);
} else {
/* There are already other overrides in effect for this thread */
assert(old_override == THREAD_QOS_USER_INTERACTIVE);
thread_unlock(thread);
splx(s);
return;
}
uint32_t new_override = THREAD_QOS_USER_INTERACTIVE;
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_SYNC_IPC_OVERRIDE,
new_override, 0, &pend_token);
assert(pend_token.tpt_update_sockets == 0);
thread_unlock(thread);
splx(s);
/*
* this is only safe after rethrottle_thread supports
* being called from spinlock context
*/
thread_policy_update_complete_unlocked(thread, &pend_token);
}
void
thread_drop_sync_ipc_override(thread_t thread)
{
struct task_pend_token pend_token = {};
spl_t s = splsched();
thread_lock(thread);
assert(thread->sync_ipc_overrides > 0);
if (--thread->sync_ipc_overrides == 0) {
/*
* There are no more overrides for this thread, so we should
* clear out the saturated override value
*/
proc_set_thread_policy_spinlocked(thread, TASK_POLICY_ATTRIBUTE,
TASK_POLICY_QOS_SYNC_IPC_OVERRIDE, THREAD_QOS_UNSPECIFIED,
0, &pend_token);
}
thread_unlock(thread);
splx(s);
/*
* this is only safe after rethrottle_thread supports
* being called from spinlock context
*/
thread_policy_update_complete_unlocked(thread, &pend_token);
}
/* Get current IPC override, may be called from spinlock context */
uint32_t
thread_get_ipc_override(thread_t thread)
{
return proc_get_thread_policy_locked(thread, TASK_POLICY_ATTRIBUTE, TASK_POLICY_QOS_IPC_OVERRIDE, NULL);
}
/*
* This function will promote the thread priority
* since exec could block other threads calling
* proc_find on the proc. This boost must be removed
* via call to thread_clear_exec_promotion.
*/
void
thread_set_exec_promotion(thread_t thread)
{
spl_t s;
s = splsched();
thread_lock(thread);
assert((thread->sched_flags & TH_SFLAG_EXEC_PROMOTED) == 0);
if (thread->sched_pri < EXEC_BOOST_PRIORITY ||
!(thread->sched_flags & TH_SFLAG_EXEC_PROMOTED)) {
KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_EXEC_PROMOTE) | DBG_FUNC_NONE,
(uintptr_t)thread_tid(thread),
thread->sched_pri, thread->base_pri,
EXEC_BOOST_PRIORITY, 0);
thread->sched_flags |= TH_SFLAG_EXEC_PROMOTED;
if (thread->sched_pri < EXEC_BOOST_PRIORITY)
set_sched_pri(thread, EXEC_BOOST_PRIORITY);
}
thread_unlock(thread);
splx(s);
}
/*
* This function will clear the exec thread
* promotion set on the thread by thread_set_exec_promotion.
*/
void
thread_clear_exec_promotion(thread_t thread)
{
spl_t s;
s = splsched();
thread_lock(thread);
assert(thread->sched_flags & TH_SFLAG_EXEC_PROMOTED);
if (thread->sched_flags & TH_SFLAG_EXEC_PROMOTED) {
thread->sched_flags &= ~TH_SFLAG_EXEC_PROMOTED;
if (thread->sched_flags & TH_SFLAG_PROMOTED_MASK) {
/* it still has other promotions (mutex/rw_lock) */
} else if (thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) {
KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_EXEC_DEMOTE) | DBG_FUNC_NONE,
(uintptr_t)thread_tid(thread),
thread->sched_pri,
thread->base_pri,
DEPRESSPRI, 0);
set_sched_pri(thread, DEPRESSPRI);
} else {
KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_EXEC_DEMOTE) | DBG_FUNC_NONE,
(uintptr_t)thread_tid(thread),
thread->sched_pri,
thread->base_pri,
thread->base_pri, 0);
thread_recompute_sched_pri(thread, FALSE);
}
}
thread_unlock(thread);
splx(s);
}