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Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (21 commits)
  sched: Remove forced2_migrations stats
  sched: Fix memory leak in two error corner cases
  sched: Fix build warning in get_update_sysctl_factor()
  sched: Update normalized values on user updates via proc
  sched: Make tunable scaling style configurable
  sched: Fix missing sched tunable recalculation on cpu add/remove
  sched: Fix task priority bug
  sched: cgroup: Implement different treatment for idle shares
  sched: Remove unnecessary RCU exclusion
  sched: Discard some old bits
  sched: Clean up check_preempt_wakeup()
  sched: Move update_curr() in check_preempt_wakeup() to avoid redundant call
  sched: Sanitize fork() handling
  sched: Clean up ttwu() rq locking
  sched: Remove rq->clock coupling from set_task_cpu()
  sched: Consolidate select_task_rq() callers
  sched: Remove sysctl.sched_features
  sched: Protect sched_rr_get_param() access to task->sched_class
  sched: Protect task->cpus_allowed access in sched_getaffinity()
  sched: Fix balance vs hotplug race
  ...

Fixed up conflicts in kernel/sysctl.c (due to sysctl cleanup)
This commit is contained in:
Linus Torvalds 2009-12-12 11:34:10 -08:00
commit 702a7c7609
11 changed files with 274 additions and 215 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
include/linux/cpumask.h
View file

@ -84,6 +84,7 @@ extern const struct cpumask *const cpu_active_mask;
#define num_online_cpus() cpumask_weight(cpu_online_mask) #define num_online_cpus() cpumask_weight(cpu_online_mask)
#define num_possible_cpus() cpumask_weight(cpu_possible_mask) #define num_possible_cpus() cpumask_weight(cpu_possible_mask)
#define num_present_cpus() cpumask_weight(cpu_present_mask) #define num_present_cpus() cpumask_weight(cpu_present_mask)
#define num_active_cpus() cpumask_weight(cpu_active_mask)
#define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask) #define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask)
#define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask) #define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask)
#define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask) #define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask)
@ -92,6 +93,7 @@ extern const struct cpumask *const cpu_active_mask;
#define num_online_cpus() 1 #define num_online_cpus() 1
#define num_possible_cpus() 1 #define num_possible_cpus() 1
#define num_present_cpus() 1 #define num_present_cpus() 1
#define num_active_cpus() 1
#define cpu_online(cpu) ((cpu) == 0) #define cpu_online(cpu) ((cpu) == 0)
#define cpu_possible(cpu) ((cpu) == 0) #define cpu_possible(cpu) ((cpu) == 0)
#define cpu_present(cpu) ((cpu) == 0) #define cpu_present(cpu) ((cpu) == 0)

20
include/linux/sched.h
View file

@ -1102,7 +1102,7 @@ struct sched_class {
void (*set_curr_task) (struct rq *rq); void (*set_curr_task) (struct rq *rq);
void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
void (*task_new) (struct rq *rq, struct task_struct *p); void (*task_fork) (struct task_struct *p);
void (*switched_from) (struct rq *this_rq, struct task_struct *task, void (*switched_from) (struct rq *this_rq, struct task_struct *task,
int running); int running);
@ -1111,7 +1111,8 @@ struct sched_class {
void (*prio_changed) (struct rq *this_rq, struct task_struct *task, void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
int oldprio, int running); int oldprio, int running);
unsigned int (*get_rr_interval) (struct task_struct *task); unsigned int (*get_rr_interval) (struct rq *rq,
struct task_struct *task);
#ifdef CONFIG_FAIR_GROUP_SCHED #ifdef CONFIG_FAIR_GROUP_SCHED
void (*moved_group) (struct task_struct *p); void (*moved_group) (struct task_struct *p);
@ -1151,8 +1152,6 @@ struct sched_entity {
u64 start_runtime; u64 start_runtime;
u64 avg_wakeup; u64 avg_wakeup;
u64 avg_running;
#ifdef CONFIG_SCHEDSTATS #ifdef CONFIG_SCHEDSTATS
u64 wait_start; u64 wait_start;
u64 wait_max; u64 wait_max;
@ -1175,7 +1174,6 @@ struct sched_entity {
u64 nr_failed_migrations_running; u64 nr_failed_migrations_running;
u64 nr_failed_migrations_hot; u64 nr_failed_migrations_hot;
u64 nr_forced_migrations; u64 nr_forced_migrations;
u64 nr_forced2_migrations;
u64 nr_wakeups; u64 nr_wakeups;
u64 nr_wakeups_sync; u64 nr_wakeups_sync;
@ -1904,14 +1902,22 @@ extern unsigned int sysctl_sched_wakeup_granularity;
extern unsigned int sysctl_sched_shares_ratelimit; extern unsigned int sysctl_sched_shares_ratelimit;
extern unsigned int sysctl_sched_shares_thresh; extern unsigned int sysctl_sched_shares_thresh;
extern unsigned int sysctl_sched_child_runs_first; extern unsigned int sysctl_sched_child_runs_first;
enum sched_tunable_scaling {
SCHED_TUNABLESCALING_NONE,
SCHED_TUNABLESCALING_LOG,
SCHED_TUNABLESCALING_LINEAR,
SCHED_TUNABLESCALING_END,
};
extern enum sched_tunable_scaling sysctl_sched_tunable_scaling;
#ifdef CONFIG_SCHED_DEBUG #ifdef CONFIG_SCHED_DEBUG
extern unsigned int sysctl_sched_features;
extern unsigned int sysctl_sched_migration_cost; extern unsigned int sysctl_sched_migration_cost;
extern unsigned int sysctl_sched_nr_migrate; extern unsigned int sysctl_sched_nr_migrate;
extern unsigned int sysctl_sched_time_avg; extern unsigned int sysctl_sched_time_avg;
extern unsigned int sysctl_timer_migration; extern unsigned int sysctl_timer_migration;
int sched_nr_latency_handler(struct ctl_table *table, int write, int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *length, void __user *buffer, size_t *length,
loff_t *ppos); loff_t *ppos);
#endif #endif

18
kernel/cpu.c
View file

@ -212,6 +212,8 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod, err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
hcpu, -1, &nr_calls); hcpu, -1, &nr_calls);
if (err == NOTIFY_BAD) { if (err == NOTIFY_BAD) {
set_cpu_active(cpu, true);
nr_calls--; nr_calls--;
__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
hcpu, nr_calls, NULL); hcpu, nr_calls, NULL);
@ -223,11 +225,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
/* Ensure that we are not runnable on dying cpu */ /* Ensure that we are not runnable on dying cpu */
cpumask_copy(old_allowed, &current->cpus_allowed); cpumask_copy(old_allowed, &current->cpus_allowed);
set_cpus_allowed_ptr(current, set_cpus_allowed_ptr(current, cpu_active_mask);
cpumask_of(cpumask_any_but(cpu_online_mask, cpu)));
err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu)); err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) { if (err) {
set_cpu_active(cpu, true);
/* CPU didn't die: tell everyone. Can't complain. */ /* CPU didn't die: tell everyone. Can't complain. */
if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
hcpu) == NOTIFY_BAD) hcpu) == NOTIFY_BAD)
@ -292,9 +294,6 @@ int __ref cpu_down(unsigned int cpu)
err = _cpu_down(cpu, 0); err = _cpu_down(cpu, 0);
if (cpu_online(cpu))
set_cpu_active(cpu, true);
out: out:
cpu_maps_update_done(); cpu_maps_update_done();
stop_machine_destroy(); stop_machine_destroy();
@ -387,6 +386,15 @@ int disable_nonboot_cpus(void)
* with the userspace trying to use the CPU hotplug at the same time * with the userspace trying to use the CPU hotplug at the same time
*/ */
cpumask_clear(frozen_cpus); cpumask_clear(frozen_cpus);
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
set_cpu_active(cpu, false);
}
synchronize_sched();
printk("Disabling non-boot CPUs ...\n"); printk("Disabling non-boot CPUs ...\n");
for_each_online_cpu(cpu) { for_each_online_cpu(cpu) {
if (cpu == first_cpu) if (cpu == first_cpu)

18
kernel/cpuset.c
View file

@ -737,7 +737,7 @@ static void do_rebuild_sched_domains(struct work_struct *unused)
{ {
} }
static int generate_sched_domains(struct cpumask **domains, static int generate_sched_domains(cpumask_var_t **domains,
struct sched_domain_attr **attributes) struct sched_domain_attr **attributes)
{ {
*domains = NULL; *domains = NULL;
@ -872,7 +872,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
if (retval < 0) if (retval < 0)
return retval; return retval;
if (!cpumask_subset(trialcs->cpus_allowed, cpu_online_mask)) if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask))
return -EINVAL; return -EINVAL;
} }
retval = validate_change(cs, trialcs); retval = validate_change(cs, trialcs);
@ -2010,7 +2010,7 @@ static void scan_for_empty_cpusets(struct cpuset *root)
} }
/* Continue past cpusets with all cpus, mems online */ /* Continue past cpusets with all cpus, mems online */
if (cpumask_subset(cp->cpus_allowed, cpu_online_mask) && if (cpumask_subset(cp->cpus_allowed, cpu_active_mask) &&
nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY])) nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))
continue; continue;
@ -2019,7 +2019,7 @@ static void scan_for_empty_cpusets(struct cpuset *root)
/* Remove offline cpus and mems from this cpuset. */ /* Remove offline cpus and mems from this cpuset. */
mutex_lock(&callback_mutex); mutex_lock(&callback_mutex);
cpumask_and(cp->cpus_allowed, cp->cpus_allowed, cpumask_and(cp->cpus_allowed, cp->cpus_allowed,
cpu_online_mask); cpu_active_mask);
nodes_and(cp->mems_allowed, cp->mems_allowed, nodes_and(cp->mems_allowed, cp->mems_allowed,
node_states[N_HIGH_MEMORY]); node_states[N_HIGH_MEMORY]);
mutex_unlock(&callback_mutex); mutex_unlock(&callback_mutex);
@ -2057,8 +2057,10 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
switch (phase) { switch (phase) {
case CPU_ONLINE: case CPU_ONLINE:
case CPU_ONLINE_FROZEN: case CPU_ONLINE_FROZEN:
case CPU_DEAD: case CPU_DOWN_PREPARE:
case CPU_DEAD_FROZEN: case CPU_DOWN_PREPARE_FROZEN:
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
break; break;
default: default:
@ -2067,7 +2069,7 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb,
cgroup_lock(); cgroup_lock();
mutex_lock(&callback_mutex); mutex_lock(&callback_mutex);
cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask); cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
mutex_unlock(&callback_mutex); mutex_unlock(&callback_mutex);
scan_for_empty_cpusets(&top_cpuset); scan_for_empty_cpusets(&top_cpuset);
ndoms = generate_sched_domains(&doms, &attr); ndoms = generate_sched_domains(&doms, &attr);
@ -2114,7 +2116,7 @@ static int cpuset_track_online_nodes(struct notifier_block *self,
void __init cpuset_init_smp(void) void __init cpuset_init_smp(void)
{ {
cpumask_copy(top_cpuset.cpus_allowed, cpu_online_mask); cpumask_copy(top_cpuset.cpus_allowed, cpu_active_mask);
top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY]; top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
hotcpu_notifier(cpuset_track_online_cpus, 0); hotcpu_notifier(cpuset_track_online_cpus, 0);

224
kernel/sched.c
View file

@ -814,6 +814,7 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
* default: 0.25ms * default: 0.25ms
*/ */
unsigned int sysctl_sched_shares_ratelimit = 250000; unsigned int sysctl_sched_shares_ratelimit = 250000;
unsigned int normalized_sysctl_sched_shares_ratelimit = 250000;
/* /*
* Inject some fuzzyness into changing the per-cpu group shares * Inject some fuzzyness into changing the per-cpu group shares
@ -1614,7 +1615,7 @@ static void update_group_shares_cpu(struct task_group *tg, int cpu,
*/ */
static int tg_shares_up(struct task_group *tg, void *data) static int tg_shares_up(struct task_group *tg, void *data)
{ {
unsigned long weight, rq_weight = 0, shares = 0; unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
unsigned long *usd_rq_weight; unsigned long *usd_rq_weight;
struct sched_domain *sd = data; struct sched_domain *sd = data;
unsigned long flags; unsigned long flags;
@ -1630,6 +1631,7 @@ static int tg_shares_up(struct task_group *tg, void *data)
weight = tg->cfs_rq[i]->load.weight; weight = tg->cfs_rq[i]->load.weight;
usd_rq_weight[i] = weight; usd_rq_weight[i] = weight;
rq_weight += weight;
/* /*
* If there are currently no tasks on the cpu pretend there * If there are currently no tasks on the cpu pretend there
* is one of average load so that when a new task gets to * is one of average load so that when a new task gets to
@ -1638,10 +1640,13 @@ static int tg_shares_up(struct task_group *tg, void *data)
if (!weight) if (!weight)
weight = NICE_0_LOAD; weight = NICE_0_LOAD;
rq_weight += weight; sum_weight += weight;
shares += tg->cfs_rq[i]->shares; shares += tg->cfs_rq[i]->shares;
} }
if (!rq_weight)
rq_weight = sum_weight;
if ((!shares && rq_weight) || shares > tg->shares) if ((!shares && rq_weight) || shares > tg->shares)
shares = tg->shares; shares = tg->shares;
@ -1810,6 +1815,22 @@ static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares)
#endif #endif
static void calc_load_account_active(struct rq *this_rq); static void calc_load_account_active(struct rq *this_rq);
static void update_sysctl(void);
static int get_update_sysctl_factor(void);
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
set_task_rq(p, cpu);
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
* successfuly executed on another CPU. We must ensure that updates of
* per-task data have been completed by this moment.
*/
smp_wmb();
task_thread_info(p)->cpu = cpu;
#endif
}
#include "sched_stats.h" #include "sched_stats.h"
#include "sched_idletask.c" #include "sched_idletask.c"
@ -1967,20 +1988,6 @@ inline int task_curr(const struct task_struct *p)
return cpu_curr(task_cpu(p)) == p; return cpu_curr(task_cpu(p)) == p;
} }
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
set_task_rq(p, cpu);
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
* successfuly executed on another CPU. We must ensure that updates of
* per-task data have been completed by this moment.
*/
smp_wmb();
task_thread_info(p)->cpu = cpu;
#endif
}
static inline void check_class_changed(struct rq *rq, struct task_struct *p, static inline void check_class_changed(struct rq *rq, struct task_struct *p,
const struct sched_class *prev_class, const struct sched_class *prev_class,
int oldprio, int running) int oldprio, int running)
@ -2060,29 +2067,13 @@ task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
void set_task_cpu(struct task_struct *p, unsigned int new_cpu) void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{ {
int old_cpu = task_cpu(p); int old_cpu = task_cpu(p);
struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu);
struct cfs_rq *old_cfsrq = task_cfs_rq(p), struct cfs_rq *old_cfsrq = task_cfs_rq(p),
*new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu);
u64 clock_offset;
clock_offset = old_rq->clock - new_rq->clock;
trace_sched_migrate_task(p, new_cpu); trace_sched_migrate_task(p, new_cpu);
#ifdef CONFIG_SCHEDSTATS
if (p->se.wait_start)
p->se.wait_start -= clock_offset;
if (p->se.sleep_start)
p->se.sleep_start -= clock_offset;
if (p->se.block_start)
p->se.block_start -= clock_offset;
#endif
if (old_cpu != new_cpu) { if (old_cpu != new_cpu) {
p->se.nr_migrations++; p->se.nr_migrations++;
#ifdef CONFIG_SCHEDSTATS
if (task_hot(p, old_rq->clock, NULL))
schedstat_inc(p, se.nr_forced2_migrations);
#endif
perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS,
1, 1, NULL, 0); 1, 1, NULL, 0);
} }
@ -2323,6 +2314,14 @@ void task_oncpu_function_call(struct task_struct *p,
preempt_enable(); preempt_enable();
} }
#ifdef CONFIG_SMP
static inline
int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
{
return p->sched_class->select_task_rq(p, sd_flags, wake_flags);
}
#endif
/*** /***
* try_to_wake_up - wake up a thread * try_to_wake_up - wake up a thread
* @p: the to-be-woken-up thread * @p: the to-be-woken-up thread
@ -2374,17 +2373,14 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
if (task_contributes_to_load(p)) if (task_contributes_to_load(p))
rq->nr_uninterruptible--; rq->nr_uninterruptible--;
p->state = TASK_WAKING; p->state = TASK_WAKING;
task_rq_unlock(rq, &flags); __task_rq_unlock(rq);
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, wake_flags); cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu) { if (cpu != orig_cpu)
local_irq_save(flags);
rq = cpu_rq(cpu);
update_rq_clock(rq);
set_task_cpu(p, cpu); set_task_cpu(p, cpu);
local_irq_restore(flags);
} rq = __task_rq_lock(p);
rq = task_rq_lock(p, &flags); update_rq_clock(rq);
WARN_ON(p->state != TASK_WAKING); WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p); cpu = task_cpu(p);
@ -2499,7 +2495,6 @@ static void __sched_fork(struct task_struct *p)
p->se.avg_overlap = 0; p->se.avg_overlap = 0;
p->se.start_runtime = 0; p->se.start_runtime = 0;
p->se.avg_wakeup = sysctl_sched_wakeup_granularity; p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
p->se.avg_running = 0;
#ifdef CONFIG_SCHEDSTATS #ifdef CONFIG_SCHEDSTATS
p->se.wait_start = 0; p->se.wait_start = 0;
@ -2521,7 +2516,6 @@ static void __sched_fork(struct task_struct *p)
p->se.nr_failed_migrations_running = 0; p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0; p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0; p->se.nr_forced_migrations = 0;
p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0; p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0; p->se.nr_wakeups_sync = 0;
@ -2558,7 +2552,6 @@ static void __sched_fork(struct task_struct *p)
void sched_fork(struct task_struct *p, int clone_flags) void sched_fork(struct task_struct *p, int clone_flags)
{ {
int cpu = get_cpu(); int cpu = get_cpu();
unsigned long flags;
__sched_fork(p); __sched_fork(p);
@ -2592,13 +2585,13 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (!rt_prio(p->prio)) if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class; p->sched_class = &fair_sched_class;
if (p->sched_class->task_fork)
p->sched_class->task_fork(p);
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0); cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
#endif #endif
local_irq_save(flags);
update_rq_clock(cpu_rq(cpu));
set_task_cpu(p, cpu); set_task_cpu(p, cpu);
local_irq_restore(flags);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on())) if (likely(sched_info_on()))
@ -2631,17 +2624,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
rq = task_rq_lock(p, &flags); rq = task_rq_lock(p, &flags);
BUG_ON(p->state != TASK_RUNNING); BUG_ON(p->state != TASK_RUNNING);
update_rq_clock(rq); update_rq_clock(rq);
activate_task(rq, p, 0);
if (!p->sched_class->task_new || !current->se.on_rq) {
activate_task(rq, p, 0);
} else {
/*
* Let the scheduling class do new task startup
* management (if any):
*/
p->sched_class->task_new(rq, p);
inc_nr_running(rq);
}
trace_sched_wakeup_new(rq, p, 1); trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK); check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
@ -3156,7 +3139,7 @@ out:
void sched_exec(void) void sched_exec(void)
{ {
int new_cpu, this_cpu = get_cpu(); int new_cpu, this_cpu = get_cpu();
new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0); new_cpu = select_task_rq(current, SD_BALANCE_EXEC, 0);
put_cpu(); put_cpu();
if (new_cpu != this_cpu) if (new_cpu != this_cpu)
sched_migrate_task(current, new_cpu); sched_migrate_task(current, new_cpu);
@ -3172,10 +3155,6 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
deactivate_task(src_rq, p, 0); deactivate_task(src_rq, p, 0);
set_task_cpu(p, this_cpu); set_task_cpu(p, this_cpu);
activate_task(this_rq, p, 0); activate_task(this_rq, p, 0);
/*
* Note that idle threads have a prio of MAX_PRIO, for this test
* to be always true for them.
*/
check_preempt_curr(this_rq, p, 0); check_preempt_curr(this_rq, p, 0);
} }
@ -4134,7 +4113,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
unsigned long flags; unsigned long flags;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
cpumask_copy(cpus, cpu_online_mask); cpumask_copy(cpus, cpu_active_mask);
/* /*
* When power savings policy is enabled for the parent domain, idle * When power savings policy is enabled for the parent domain, idle
@ -4297,7 +4276,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
int all_pinned = 0; int all_pinned = 0;
struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
cpumask_copy(cpus, cpu_online_mask); cpumask_copy(cpus, cpu_active_mask);
/* /*
* When power savings policy is enabled for the parent domain, idle * When power savings policy is enabled for the parent domain, idle
@ -4694,7 +4673,7 @@ int select_nohz_load_balancer(int stop_tick)
cpumask_set_cpu(cpu, nohz.cpu_mask); cpumask_set_cpu(cpu, nohz.cpu_mask);
/* time for ilb owner also to sleep */ /* time for ilb owner also to sleep */
if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { if (cpumask_weight(nohz.cpu_mask) == num_active_cpus()) {
if (atomic_read(&nohz.load_balancer) == cpu) if (atomic_read(&nohz.load_balancer) == cpu)
atomic_set(&nohz.load_balancer, -1); atomic_set(&nohz.load_balancer, -1);
return 0; return 0;
@ -5396,13 +5375,14 @@ static inline void schedule_debug(struct task_struct *prev)
#endif #endif
} }
static void put_prev_task(struct rq *rq, struct task_struct *p) static void put_prev_task(struct rq *rq, struct task_struct *prev)
{ {
u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime; if (prev->state == TASK_RUNNING) {
u64 runtime = prev->se.sum_exec_runtime;
update_avg(&p->se.avg_running, runtime); runtime -= prev->se.prev_sum_exec_runtime;
runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
if (p->state == TASK_RUNNING) {
/* /*
* In order to avoid avg_overlap growing stale when we are * In order to avoid avg_overlap growing stale when we are
* indeed overlapping and hence not getting put to sleep, grow * indeed overlapping and hence not getting put to sleep, grow
@ -5412,12 +5392,9 @@ static void put_prev_task(struct rq *rq, struct task_struct *p)
* correlates to the amount of cache footprint a task can * correlates to the amount of cache footprint a task can
* build up. * build up.
*/ */
runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); update_avg(&prev->se.avg_overlap, runtime);
update_avg(&p->se.avg_overlap, runtime);
} else {
update_avg(&p->se.avg_running, 0);
} }
p->sched_class->put_prev_task(rq, p); prev->sched_class->put_prev_task(rq, prev);
} }
/* /*
@ -6631,6 +6608,8 @@ SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len,
long sched_getaffinity(pid_t pid, struct cpumask *mask) long sched_getaffinity(pid_t pid, struct cpumask *mask)
{ {
struct task_struct *p; struct task_struct *p;
unsigned long flags;
struct rq *rq;
int retval; int retval;
get_online_cpus(); get_online_cpus();
@ -6645,7 +6624,9 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
if (retval) if (retval)
goto out_unlock; goto out_unlock;
rq = task_rq_lock(p, &flags);
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
task_rq_unlock(rq, &flags);
out_unlock: out_unlock:
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
@ -6883,6 +6864,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
{ {
struct task_struct *p; struct task_struct *p;
unsigned int time_slice; unsigned int time_slice;
unsigned long flags;
struct rq *rq;
int retval; int retval;
struct timespec t; struct timespec t;
@ -6899,7 +6882,9 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
if (retval) if (retval)
goto out_unlock; goto out_unlock;
time_slice = p->sched_class->get_rr_interval(p); rq = task_rq_lock(p, &flags);
time_slice = p->sched_class->get_rr_interval(rq, p);
task_rq_unlock(rq, &flags);
read_unlock(&tasklist_lock); read_unlock(&tasklist_lock);
jiffies_to_timespec(time_slice, &t); jiffies_to_timespec(time_slice, &t);
@ -7000,7 +6985,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
__sched_fork(idle); __sched_fork(idle);
idle->se.exec_start = sched_clock(); idle->se.exec_start = sched_clock();
idle->prio = idle->normal_prio = MAX_PRIO;
cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));
__set_task_cpu(idle, cpu); __set_task_cpu(idle, cpu);
@ -7041,22 +7025,43 @@ cpumask_var_t nohz_cpu_mask;
* *
* This idea comes from the SD scheduler of Con Kolivas: * This idea comes from the SD scheduler of Con Kolivas:
*/ */
static int get_update_sysctl_factor(void)
{
unsigned int cpus = min_t(int, num_online_cpus(), 8);
unsigned int factor;
switch (sysctl_sched_tunable_scaling) {
case SCHED_TUNABLESCALING_NONE:
factor = 1;
break;
case SCHED_TUNABLESCALING_LINEAR:
factor = cpus;
break;
case SCHED_TUNABLESCALING_LOG:
default:
factor = 1 + ilog2(cpus);
break;
}
return factor;
}
static void update_sysctl(void)
{
unsigned int factor = get_update_sysctl_factor();
#define SET_SYSCTL(name) \
(sysctl_##name = (factor) * normalized_sysctl_##name)
SET_SYSCTL(sched_min_granularity);
SET_SYSCTL(sched_latency);
SET_SYSCTL(sched_wakeup_granularity);
SET_SYSCTL(sched_shares_ratelimit);
#undef SET_SYSCTL
}
static inline void sched_init_granularity(void) static inline void sched_init_granularity(void)
{ {
unsigned int factor = 1 + ilog2(num_online_cpus()); update_sysctl();
const unsigned long limit = 200000000;
sysctl_sched_min_granularity *= factor;
if (sysctl_sched_min_granularity > limit)
sysctl_sched_min_granularity = limit;
sysctl_sched_latency *= factor;
if (sysctl_sched_latency > limit)
sysctl_sched_latency = limit;
sysctl_sched_wakeup_granularity *= factor;
sysctl_sched_shares_ratelimit *= factor;
} }
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
@ -7093,7 +7098,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
int ret = 0; int ret = 0;
rq = task_rq_lock(p, &flags); rq = task_rq_lock(p, &flags);
if (!cpumask_intersects(new_mask, cpu_online_mask)) { if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL; ret = -EINVAL;
goto out; goto out;
} }
@ -7115,7 +7120,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
if (cpumask_test_cpu(task_cpu(p), new_mask)) if (cpumask_test_cpu(task_cpu(p), new_mask))
goto out; goto out;
if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) {
/* Need help from migration thread: drop lock and wait. */ /* Need help from migration thread: drop lock and wait. */
struct task_struct *mt = rq->migration_thread; struct task_struct *mt = rq->migration_thread;
@ -7269,19 +7274,19 @@ static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)
again: again:
/* Look for allowed, online CPU in same node. */ /* Look for allowed, online CPU in same node. */
for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask) for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask)
if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
goto move; goto move;
/* Any allowed, online CPU? */ /* Any allowed, online CPU? */
dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask); dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask);
if (dest_cpu < nr_cpu_ids) if (dest_cpu < nr_cpu_ids)
goto move; goto move;
/* No more Mr. Nice Guy. */ /* No more Mr. Nice Guy. */
if (dest_cpu >= nr_cpu_ids) { if (dest_cpu >= nr_cpu_ids) {
cpuset_cpus_allowed_locked(p, &p->cpus_allowed); cpuset_cpus_allowed_locked(p, &p->cpus_allowed);
dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed); dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed);
/* /*
* Don't tell them about moving exiting tasks or * Don't tell them about moving exiting tasks or
@ -7310,7 +7315,7 @@ move:
*/ */
static void migrate_nr_uninterruptible(struct rq *rq_src) static void migrate_nr_uninterruptible(struct rq *rq_src)
{ {
struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask)); struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
unsigned long flags; unsigned long flags;
local_irq_save(flags); local_irq_save(flags);
@ -7563,7 +7568,7 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
static struct ctl_table_header *sd_sysctl_header; static struct ctl_table_header *sd_sysctl_header;
static void register_sched_domain_sysctl(void) static void register_sched_domain_sysctl(void)
{ {
int i, cpu_num = num_online_cpus(); int i, cpu_num = num_possible_cpus();
struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1);
char buf[32]; char buf[32];
@ -7573,7 +7578,7 @@ static void register_sched_domain_sysctl(void)
if (entry == NULL) if (entry == NULL)
return; return;
for_each_online_cpu(i) { for_each_possible_cpu(i) {
snprintf(buf, 32, "cpu%d", i); snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL); entry->procname = kstrdup(buf, GFP_KERNEL);
entry->mode = 0555; entry->mode = 0555;
@ -7703,7 +7708,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
spin_lock_irq(&rq->lock); spin_lock_irq(&rq->lock);
update_rq_clock(rq); update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0); deactivate_task(rq, rq->idle, 0);
rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0); __setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class; rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu); migrate_dead_tasks(cpu);
@ -9099,7 +9103,7 @@ match1:
if (doms_new == NULL) { if (doms_new == NULL) {
ndoms_cur = 0; ndoms_cur = 0;
doms_new = &fallback_doms; doms_new = &fallback_doms;
cpumask_andnot(doms_new[0], cpu_online_mask, cpu_isolated_map); cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map);
WARN_ON_ONCE(dattr_new); WARN_ON_ONCE(dattr_new);
} }
@ -9230,8 +9234,10 @@ static int update_sched_domains(struct notifier_block *nfb,
switch (action) { switch (action) {
case CPU_ONLINE: case CPU_ONLINE:
case CPU_ONLINE_FROZEN: case CPU_ONLINE_FROZEN:
case CPU_DEAD: case CPU_DOWN_PREPARE:
case CPU_DEAD_FROZEN: case CPU_DOWN_PREPARE_FROZEN:
case CPU_DOWN_FAILED:
case CPU_DOWN_FAILED_FROZEN:
partition_sched_domains(1, NULL, NULL); partition_sched_domains(1, NULL, NULL);
return NOTIFY_OK; return NOTIFY_OK;
@ -9278,7 +9284,7 @@ void __init sched_init_smp(void)
#endif #endif
get_online_cpus(); get_online_cpus();
mutex_lock(&sched_domains_mutex); mutex_lock(&sched_domains_mutex);
arch_init_sched_domains(cpu_online_mask); arch_init_sched_domains(cpu_active_mask);
cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
if (cpumask_empty(non_isolated_cpus)) if (cpumask_empty(non_isolated_cpus))
cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
@ -9842,13 +9848,15 @@ int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
se = kzalloc_node(sizeof(struct sched_entity), se = kzalloc_node(sizeof(struct sched_entity),
GFP_KERNEL, cpu_to_node(i)); GFP_KERNEL, cpu_to_node(i));
if (!se) if (!se)
goto err; goto err_free_rq;
init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
} }
return 1; return 1;
err_free_rq:
kfree(cfs_rq);
err: err:
return 0; return 0;
} }
@ -9930,13 +9938,15 @@ int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
rt_se = kzalloc_node(sizeof(struct sched_rt_entity), rt_se = kzalloc_node(sizeof(struct sched_rt_entity),
GFP_KERNEL, cpu_to_node(i)); GFP_KERNEL, cpu_to_node(i));
if (!rt_se) if (!rt_se)
goto err; goto err_free_rq;
init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
} }
return 1; return 1;
err_free_rq:
kfree(rt_rq);
err: err:
return 0; return 0;
} }

13
kernel/sched_debug.c
View file

@ -309,6 +309,12 @@ static void print_cpu(struct seq_file *m, int cpu)
print_rq(m, rq, cpu); print_rq(m, rq, cpu);
} }
static const char *sched_tunable_scaling_names[] = {
"none",
"logaritmic",
"linear"
};
static int sched_debug_show(struct seq_file *m, void *v) static int sched_debug_show(struct seq_file *m, void *v)
{ {
u64 now = ktime_to_ns(ktime_get()); u64 now = ktime_to_ns(ktime_get());
@ -334,6 +340,10 @@ static int sched_debug_show(struct seq_file *m, void *v)
#undef PN #undef PN
#undef P #undef P
SEQ_printf(m, " .%-40s: %d (%s)\n", "sysctl_sched_tunable_scaling",
sysctl_sched_tunable_scaling,
sched_tunable_scaling_names[sysctl_sched_tunable_scaling]);
for_each_online_cpu(cpu) for_each_online_cpu(cpu)
print_cpu(m, cpu); print_cpu(m, cpu);
@ -399,7 +409,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
PN(se.sum_exec_runtime); PN(se.sum_exec_runtime);
PN(se.avg_overlap); PN(se.avg_overlap);
PN(se.avg_wakeup); PN(se.avg_wakeup);
PN(se.avg_running);
nr_switches = p->nvcsw + p->nivcsw; nr_switches = p->nvcsw + p->nivcsw;
@ -423,7 +432,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
P(se.nr_failed_migrations_running); P(se.nr_failed_migrations_running);
P(se.nr_failed_migrations_hot); P(se.nr_failed_migrations_hot);
P(se.nr_forced_migrations); P(se.nr_forced_migrations);
P(se.nr_forced2_migrations);
P(se.nr_wakeups); P(se.nr_wakeups);
P(se.nr_wakeups_sync); P(se.nr_wakeups_sync);
P(se.nr_wakeups_migrate); P(se.nr_wakeups_migrate);
@ -499,7 +507,6 @@ void proc_sched_set_task(struct task_struct *p)
p->se.nr_failed_migrations_running = 0; p->se.nr_failed_migrations_running = 0;
p->se.nr_failed_migrations_hot = 0; p->se.nr_failed_migrations_hot = 0;
p->se.nr_forced_migrations = 0; p->se.nr_forced_migrations = 0;
p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 0; p->se.nr_wakeups = 0;
p->se.nr_wakeups_sync = 0; p->se.nr_wakeups_sync = 0;
p->se.nr_wakeups_migrate = 0; p->se.nr_wakeups_migrate = 0;

155
kernel/sched_fair.c
View file

@ -21,6 +21,7 @@
*/ */
#include <linux/latencytop.h> #include <linux/latencytop.h>
#include <linux/sched.h>
/* /*
* Targeted preemption latency for CPU-bound tasks: * Targeted preemption latency for CPU-bound tasks:
@ -35,12 +36,26 @@
* run vmstat and monitor the context-switches (cs) field) * run vmstat and monitor the context-switches (cs) field)
*/ */
unsigned int sysctl_sched_latency = 5000000ULL; unsigned int sysctl_sched_latency = 5000000ULL;
unsigned int normalized_sysctl_sched_latency = 5000000ULL;
/*
* The initial- and re-scaling of tunables is configurable
* (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
*
* Options are:
* SCHED_TUNABLESCALING_NONE - unscaled, always *1
* SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
* SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
*/
enum sched_tunable_scaling sysctl_sched_tunable_scaling
= SCHED_TUNABLESCALING_LOG;
/* /*
* Minimal preemption granularity for CPU-bound tasks: * Minimal preemption granularity for CPU-bound tasks:
* (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/ */
unsigned int sysctl_sched_min_granularity = 1000000ULL; unsigned int sysctl_sched_min_granularity = 1000000ULL;
unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL;
/* /*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity * is kept at sysctl_sched_latency / sysctl_sched_min_granularity
@ -70,6 +85,7 @@ unsigned int __read_mostly sysctl_sched_compat_yield;
* have immediate wakeup/sleep latencies. * have immediate wakeup/sleep latencies.
*/ */
unsigned int sysctl_sched_wakeup_granularity = 1000000UL; unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
@ -383,11 +399,12 @@ static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
*/ */
#ifdef CONFIG_SCHED_DEBUG #ifdef CONFIG_SCHED_DEBUG
int sched_nr_latency_handler(struct ctl_table *table, int write, int sched_proc_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, void __user *buffer, size_t *lenp,
loff_t *ppos) loff_t *ppos)
{ {
int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
int factor = get_update_sysctl_factor();
if (ret || !write) if (ret || !write)
return ret; return ret;
@ -395,6 +412,14 @@ int sched_nr_latency_handler(struct ctl_table *table, int write,
sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency, sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
sysctl_sched_min_granularity); sysctl_sched_min_granularity);
#define WRT_SYSCTL(name) \
(normalized_sysctl_##name = sysctl_##name / (factor))
WRT_SYSCTL(sched_min_granularity);
WRT_SYSCTL(sched_latency);
WRT_SYSCTL(sched_wakeup_granularity);
WRT_SYSCTL(sched_shares_ratelimit);
#undef WRT_SYSCTL
return 0; return 0;
} }
#endif #endif
@ -1403,7 +1428,6 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
new_cpu = prev_cpu; new_cpu = prev_cpu;
} }
rcu_read_lock();
for_each_domain(cpu, tmp) { for_each_domain(cpu, tmp) {
/* /*
* If power savings logic is enabled for a domain, see if we * If power savings logic is enabled for a domain, see if we
@ -1484,10 +1508,8 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
update_shares(tmp); update_shares(tmp);
} }
if (affine_sd && wake_affine(affine_sd, p, sync)) { if (affine_sd && wake_affine(affine_sd, p, sync))
new_cpu = cpu; return cpu;
goto out;
}
while (sd) { while (sd) {
int load_idx = sd->forkexec_idx; int load_idx = sd->forkexec_idx;
@ -1528,8 +1550,6 @@ static int select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flag
/* while loop will break here if sd == NULL */ /* while loop will break here if sd == NULL */
} }
out:
rcu_read_unlock();
return new_cpu; return new_cpu;
} }
#endif /* CONFIG_SMP */ #endif /* CONFIG_SMP */
@ -1651,12 +1671,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
int sync = wake_flags & WF_SYNC; int sync = wake_flags & WF_SYNC;
int scale = cfs_rq->nr_running >= sched_nr_latency; int scale = cfs_rq->nr_running >= sched_nr_latency;
update_curr(cfs_rq); if (unlikely(rt_prio(p->prio)))
goto preempt;
if (unlikely(rt_prio(p->prio))) {
resched_task(curr);
return;
}
if (unlikely(p->sched_class != &fair_sched_class)) if (unlikely(p->sched_class != &fair_sched_class))
return; return;
@ -1682,50 +1698,44 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
return; return;
/* Idle tasks are by definition preempted by everybody. */ /* Idle tasks are by definition preempted by everybody. */
if (unlikely(curr->policy == SCHED_IDLE)) { if (unlikely(curr->policy == SCHED_IDLE))
resched_task(curr); goto preempt;
return;
}
if ((sched_feat(WAKEUP_SYNC) && sync) || if (sched_feat(WAKEUP_SYNC) && sync)
(sched_feat(WAKEUP_OVERLAP) && goto preempt;
(se->avg_overlap < sysctl_sched_migration_cost &&
pse->avg_overlap < sysctl_sched_migration_cost))) {
resched_task(curr);
return;
}
if (sched_feat(WAKEUP_RUNNING)) { if (sched_feat(WAKEUP_OVERLAP) &&
if (pse->avg_running < se->avg_running) { se->avg_overlap < sysctl_sched_migration_cost &&
set_next_buddy(pse); pse->avg_overlap < sysctl_sched_migration_cost)
resched_task(curr); goto preempt;
return;
}
}
if (!sched_feat(WAKEUP_PREEMPT)) if (!sched_feat(WAKEUP_PREEMPT))
return; return;
update_curr(cfs_rq);
find_matching_se(&se, &pse); find_matching_se(&se, &pse);
BUG_ON(!pse); BUG_ON(!pse);
if (wakeup_preempt_entity(se, pse) == 1)
goto preempt;
if (wakeup_preempt_entity(se, pse) == 1) { return;
resched_task(curr);
/* preempt:
* Only set the backward buddy when the current task is still resched_task(curr);
* on the rq. This can happen when a wakeup gets interleaved /*
* with schedule on the ->pre_schedule() or idle_balance() * Only set the backward buddy when the current task is still
* point, either of which can * drop the rq lock. * on the rq. This can happen when a wakeup gets interleaved
* * with schedule on the ->pre_schedule() or idle_balance()
* Also, during early boot the idle thread is in the fair class, * point, either of which can * drop the rq lock.
* for obvious reasons its a bad idea to schedule back to it. *
*/ * Also, during early boot the idle thread is in the fair class,
if (unlikely(!se->on_rq || curr == rq->idle)) * for obvious reasons its a bad idea to schedule back to it.
return; */
if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se)) if (unlikely(!se->on_rq || curr == rq->idle))
set_last_buddy(se); return;
}
if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
set_last_buddy(se);
} }
static struct task_struct *pick_next_task_fair(struct rq *rq) static struct task_struct *pick_next_task_fair(struct rq *rq)
@ -1905,6 +1915,17 @@ move_one_task_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
return 0; return 0;
} }
static void rq_online_fair(struct rq *rq)
{
update_sysctl();
}
static void rq_offline_fair(struct rq *rq)
{
update_sysctl();
}
#endif /* CONFIG_SMP */ #endif /* CONFIG_SMP */
/* /*
@ -1922,28 +1943,30 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
} }
/* /*
* Share the fairness runtime between parent and child, thus the * called on fork with the child task as argument from the parent's context
* total amount of pressure for CPU stays equal - new tasks * - child not yet on the tasklist
* get a chance to run but frequent forkers are not allowed to * - preemption disabled
* monopolize the CPU. Note: the parent runqueue is locked,
* the child is not running yet.
*/ */
static void task_new_fair(struct rq *rq, struct task_struct *p) static void task_fork_fair(struct task_struct *p)
{ {
struct cfs_rq *cfs_rq = task_cfs_rq(p); struct cfs_rq *cfs_rq = task_cfs_rq(current);
struct sched_entity *se = &p->se, *curr = cfs_rq->curr; struct sched_entity *se = &p->se, *curr = cfs_rq->curr;
int this_cpu = smp_processor_id(); int this_cpu = smp_processor_id();
struct rq *rq = this_rq();
unsigned long flags;
sched_info_queued(p); spin_lock_irqsave(&rq->lock, flags);
if (unlikely(task_cpu(p) != this_cpu))
__set_task_cpu(p, this_cpu);
update_curr(cfs_rq); update_curr(cfs_rq);
if (curr) if (curr)
se->vruntime = curr->vruntime; se->vruntime = curr->vruntime;
place_entity(cfs_rq, se, 1); place_entity(cfs_rq, se, 1);
/* 'curr' will be NULL if the child belongs to a different group */ if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) {
if (sysctl_sched_child_runs_first && this_cpu == task_cpu(p) &&
curr && entity_before(curr, se)) {
/* /*
* Upon rescheduling, sched_class::put_prev_task() will place * Upon rescheduling, sched_class::put_prev_task() will place
* 'current' within the tree based on its new key value. * 'current' within the tree based on its new key value.
@ -1952,7 +1975,7 @@ static void task_new_fair(struct rq *rq, struct task_struct *p)
resched_task(rq->curr); resched_task(rq->curr);
} }
enqueue_task_fair(rq, p, 0); spin_unlock_irqrestore(&rq->lock, flags);
} }
/* /*
@ -2014,21 +2037,17 @@ static void moved_group_fair(struct task_struct *p)
} }
#endif #endif
unsigned int get_rr_interval_fair(struct task_struct *task) unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task)
{ {
struct sched_entity *se = &task->se; struct sched_entity *se = &task->se;
unsigned long flags;
struct rq *rq;
unsigned int rr_interval = 0; unsigned int rr_interval = 0;
/* /*
* Time slice is 0 for SCHED_OTHER tasks that are on an otherwise * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
* idle runqueue: * idle runqueue:
*/ */
rq = task_rq_lock(task, &flags);
if (rq->cfs.load.weight) if (rq->cfs.load.weight)
rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
task_rq_unlock(rq, &flags);
return rr_interval; return rr_interval;
} }
@ -2052,11 +2071,13 @@ static const struct sched_class fair_sched_class = {
.load_balance = load_balance_fair, .load_balance = load_balance_fair,
.move_one_task = move_one_task_fair, .move_one_task = move_one_task_fair,
.rq_online = rq_online_fair,
.rq_offline = rq_offline_fair,
#endif #endif
.set_curr_task = set_curr_task_fair, .set_curr_task = set_curr_task_fair,
.task_tick = task_tick_fair, .task_tick = task_tick_fair,
.task_new = task_new_fair, .task_fork = task_fork_fair,
.prio_changed = prio_changed_fair, .prio_changed = prio_changed_fair,
.switched_to = switched_to_fair, .switched_to = switched_to_fair,

5
kernel/sched_features.h
View file

@ -53,11 +53,6 @@ SCHED_FEAT(WAKEUP_SYNC, 0)
*/ */
SCHED_FEAT(WAKEUP_OVERLAP, 0) SCHED_FEAT(WAKEUP_OVERLAP, 0)
/*
* Wakeup preemption towards tasks that run short
*/
SCHED_FEAT(WAKEUP_RUNNING, 0)
/* /*
* Use the SYNC wakeup hint, pipes and the likes use this to indicate * Use the SYNC wakeup hint, pipes and the likes use this to indicate
* the remote end is likely to consume the data we just wrote, and * the remote end is likely to consume the data we just wrote, and

2
kernel/sched_idletask.c
View file

@ -97,7 +97,7 @@ static void prio_changed_idle(struct rq *rq, struct task_struct *p,
check_preempt_curr(rq, p, 0); check_preempt_curr(rq, p, 0);
} }
unsigned int get_rr_interval_idle(struct task_struct *task) unsigned int get_rr_interval_idle(struct rq *rq, struct task_struct *task)
{ {
return 0; return 0;
} }

2
kernel/sched_rt.c
View file

@ -1721,7 +1721,7 @@ static void set_curr_task_rt(struct rq *rq)
dequeue_pushable_task(rq, p); dequeue_pushable_task(rq, p);
} }
unsigned int get_rr_interval_rt(struct task_struct *task) unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task)
{ {
/* /*
* Time slice is 0 for SCHED_FIFO tasks * Time slice is 0 for SCHED_FIFO tasks

30
kernel/sysctl.c
View file

@ -244,6 +244,10 @@ static int min_sched_granularity_ns = 100000; /* 100 usecs */
static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */ static int max_sched_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_wakeup_granularity_ns; /* 0 usecs */ static int min_wakeup_granularity_ns; /* 0 usecs */
static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */ static int max_wakeup_granularity_ns = NSEC_PER_SEC; /* 1 second */
static int min_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE;
static int max_sched_tunable_scaling = SCHED_TUNABLESCALING_END-1;
static int min_sched_shares_ratelimit = 100000; /* 100 usec */
static int max_sched_shares_ratelimit = NSEC_PER_SEC; /* 1 second */
#endif #endif
static struct ctl_table kern_table[] = { static struct ctl_table kern_table[] = {
@ -260,7 +264,7 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_sched_min_granularity, .data = &sysctl_sched_min_granularity,
.maxlen = sizeof(unsigned int), .maxlen = sizeof(unsigned int),
.mode = 0644, .mode = 0644,
.proc_handler = sched_nr_latency_handler, .proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_granularity_ns, .extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns, .extra2 = &max_sched_granularity_ns,
}, },
@ -269,7 +273,7 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_sched_latency, .data = &sysctl_sched_latency,
.maxlen = sizeof(unsigned int), .maxlen = sizeof(unsigned int),
.mode = 0644, .mode = 0644,
.proc_handler = sched_nr_latency_handler, .proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_granularity_ns, .extra1 = &min_sched_granularity_ns,
.extra2 = &max_sched_granularity_ns, .extra2 = &max_sched_granularity_ns,
}, },
@ -278,7 +282,7 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_sched_wakeup_granularity, .data = &sysctl_sched_wakeup_granularity,
.maxlen = sizeof(unsigned int), .maxlen = sizeof(unsigned int),
.mode = 0644, .mode = 0644,
.proc_handler = proc_dointvec_minmax, .proc_handler = sched_proc_update_handler,
.extra1 = &min_wakeup_granularity_ns, .extra1 = &min_wakeup_granularity_ns,
.extra2 = &max_wakeup_granularity_ns, .extra2 = &max_wakeup_granularity_ns,
}, },
@ -287,7 +291,18 @@ static struct ctl_table kern_table[] = {
.data = &sysctl_sched_shares_ratelimit, .data = &sysctl_sched_shares_ratelimit,
.maxlen = sizeof(unsigned int), .maxlen = sizeof(unsigned int),
.mode = 0644, .mode = 0644,
.proc_handler = proc_dointvec, .proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_shares_ratelimit,
.extra2 = &max_sched_shares_ratelimit,
},
{
.procname = "sched_tunable_scaling",
.data = &sysctl_sched_tunable_scaling,
.maxlen = sizeof(enum sched_tunable_scaling),
.mode = 0644,
.proc_handler = sched_proc_update_handler,
.extra1 = &min_sched_tunable_scaling,
.extra2 = &max_sched_tunable_scaling,
}, },
{ {
.procname = "sched_shares_thresh", .procname = "sched_shares_thresh",
@ -297,13 +312,6 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec_minmax, .proc_handler = proc_dointvec_minmax,
.extra1 = &zero, .extra1 = &zero,
}, },
{
.procname = "sched_features",
.data = &sysctl_sched_features,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ {
.procname = "sched_migration_cost", .procname = "sched_migration_cost",
.data = &sysctl_sched_migration_cost, .data = &sysctl_sched_migration_cost,