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authorLinus Torvalds <torvalds@linux-foundation.org>2009-12-12 11:34:10 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-12 11:34:10 -0800
commit702a7c7609bec3a940b6a46b0d6ab9ce45274580 (patch)
tree6c169691449259410b9b51a146acb0e837dae96a /kernel/sched.c
parent053fe57ac249a9531c396175778160d9e9509399 (diff)
parentb9889ed1ddeca5a3f3569c8de7354e9e97d803ae (diff)
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* '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)
Diffstat (limited to 'kernel/sched.c')
-rw-r--r--kernel/sched.c218
1 files changed, 114 insertions, 104 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index e7f2cfa6a257..ff39cadf621e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -814,6 +814,7 @@ const_debug unsigned int sysctl_sched_nr_migrate = 32;
* default: 0.25ms
*/
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
@@ -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)
{
- unsigned long weight, rq_weight = 0, shares = 0;
+ unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0;
unsigned long *usd_rq_weight;
struct sched_domain *sd = data;
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;
usd_rq_weight[i] = weight;
+ rq_weight += weight;
/*
* If there are currently no tasks on the cpu pretend there
* 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)
weight = NICE_0_LOAD;
- rq_weight += weight;
+ sum_weight += weight;
shares += tg->cfs_rq[i]->shares;
}
+ if (!rq_weight)
+ rq_weight = sum_weight;
+
if ((!shares && rq_weight) || 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
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_idletask.c"
@@ -1967,20 +1988,6 @@ inline int task_curr(const struct task_struct *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,
const struct sched_class *prev_class,
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)
{
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),
*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);
-#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) {
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,
1, 1, NULL, 0);
}
@@ -2323,6 +2314,14 @@ void task_oncpu_function_call(struct task_struct *p,
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
* @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))
rq->nr_uninterruptible--;
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);
- if (cpu != orig_cpu) {
- local_irq_save(flags);
- rq = cpu_rq(cpu);
- update_rq_clock(rq);
+ cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
+ if (cpu != orig_cpu)
set_task_cpu(p, cpu);
- local_irq_restore(flags);
- }
- rq = task_rq_lock(p, &flags);
+
+ rq = __task_rq_lock(p);
+ update_rq_clock(rq);
WARN_ON(p->state != TASK_WAKING);
cpu = task_cpu(p);
@@ -2499,7 +2495,6 @@ static void __sched_fork(struct task_struct *p)
p->se.avg_overlap = 0;
p->se.start_runtime = 0;
p->se.avg_wakeup = sysctl_sched_wakeup_granularity;
- p->se.avg_running = 0;
#ifdef CONFIG_SCHEDSTATS
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_hot = 0;
p->se.nr_forced_migrations = 0;
- p->se.nr_forced2_migrations = 0;
p->se.nr_wakeups = 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)
{
int cpu = get_cpu();
- unsigned long flags;
__sched_fork(p);
@@ -2592,13 +2585,13 @@ void sched_fork(struct task_struct *p, int clone_flags)
if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class;
+ if (p->sched_class->task_fork)
+ p->sched_class->task_fork(p);
+
#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
- local_irq_save(flags);
- update_rq_clock(cpu_rq(cpu));
set_task_cpu(p, cpu);
- local_irq_restore(flags);
#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
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);
BUG_ON(p->state != TASK_RUNNING);
update_rq_clock(rq);
-
- 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);
- }
+ activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
check_preempt_curr(rq, p, WF_FORK);
#ifdef CONFIG_SMP
@@ -3156,7 +3139,7 @@ out:
void sched_exec(void)
{
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();
if (new_cpu != this_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);
set_task_cpu(p, this_cpu);
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);
}
@@ -4134,7 +4113,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
unsigned long flags;
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
@@ -4297,7 +4276,7 @@ load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd)
int all_pinned = 0;
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
@@ -4694,7 +4673,7 @@ int select_nohz_load_balancer(int stop_tick)
cpumask_set_cpu(cpu, nohz.cpu_mask);
/* 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)
atomic_set(&nohz.load_balancer, -1);
return 0;
@@ -5396,13 +5375,14 @@ static inline void schedule_debug(struct task_struct *prev)
#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
* 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
* build up.
*/
- runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
- update_avg(&p->se.avg_overlap, runtime);
- } else {
- update_avg(&p->se.avg_running, 0);
+ update_avg(&prev->se.avg_overlap, runtime);
}
- 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)
{
struct task_struct *p;
+ unsigned long flags;
+ struct rq *rq;
int retval;
get_online_cpus();
@@ -6645,7 +6624,9 @@ long sched_getaffinity(pid_t pid, struct cpumask *mask)
if (retval)
goto out_unlock;
+ rq = task_rq_lock(p, &flags);
cpumask_and(mask, &p->cpus_allowed, cpu_online_mask);
+ task_rq_unlock(rq, &flags);
out_unlock:
read_unlock(&tasklist_lock);
@@ -6883,6 +6864,8 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
{
struct task_struct *p;
unsigned int time_slice;
+ unsigned long flags;
+ struct rq *rq;
int retval;
struct timespec t;
@@ -6899,7 +6882,9 @@ SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
if (retval)
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);
jiffies_to_timespec(time_slice, &t);
@@ -7000,7 +6985,6 @@ void __cpuinit init_idle(struct task_struct *idle, int cpu)
__sched_fork(idle);
idle->se.exec_start = sched_clock();
- idle->prio = idle->normal_prio = MAX_PRIO;
cpumask_copy(&idle->cpus_allowed, cpumask_of(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:
*/
-static inline void sched_init_granularity(void)
+static int get_update_sysctl_factor(void)
{
- unsigned int factor = 1 + ilog2(num_online_cpus());
- const unsigned long limit = 200000000;
+ 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;
+ }
- sysctl_sched_min_granularity *= factor;
- if (sysctl_sched_min_granularity > limit)
- sysctl_sched_min_granularity = limit;
+ return factor;
+}
- sysctl_sched_latency *= factor;
- if (sysctl_sched_latency > limit)
- sysctl_sched_latency = limit;
+static void update_sysctl(void)
+{
+ unsigned int factor = get_update_sysctl_factor();
- sysctl_sched_wakeup_granularity *= 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
+}
- sysctl_sched_shares_ratelimit *= factor;
+static inline void sched_init_granularity(void)
+{
+ update_sysctl();
}
#ifdef CONFIG_SMP
@@ -7093,7 +7098,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
int ret = 0;
rq = task_rq_lock(p, &flags);
- if (!cpumask_intersects(new_mask, cpu_online_mask)) {
+ if (!cpumask_intersects(new_mask, cpu_active_mask)) {
ret = -EINVAL;
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))
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. */
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:
/* 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))
goto move;
/* 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)
goto move;
/* No more Mr. Nice Guy. */
if (dest_cpu >= nr_cpu_ids) {
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
@@ -7310,7 +7315,7 @@ move:
*/
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;
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 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);
char buf[32];
@@ -7573,7 +7578,7 @@ static void register_sched_domain_sysctl(void)
if (entry == NULL)
return;
- for_each_online_cpu(i) {
+ for_each_possible_cpu(i) {
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
entry->mode = 0555;
@@ -7703,7 +7708,6 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
spin_lock_irq(&rq->lock);
update_rq_clock(rq);
deactivate_task(rq, rq->idle, 0);
- rq->idle->static_prio = MAX_PRIO;
__setscheduler(rq, rq->idle, SCHED_NORMAL, 0);
rq->idle->sched_class = &idle_sched_class;
migrate_dead_tasks(cpu);
@@ -9099,7 +9103,7 @@ match1:
if (doms_new == NULL) {
ndoms_cur = 0;
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);
}
@@ -9230,8 +9234,10 @@ static int update_sched_domains(struct notifier_block *nfb,
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
+ case CPU_DOWN_PREPARE:
+ case CPU_DOWN_PREPARE_FROZEN:
+ case CPU_DOWN_FAILED:
+ case CPU_DOWN_FAILED_FROZEN:
partition_sched_domains(1, NULL, NULL);
return NOTIFY_OK;
@@ -9278,7 +9284,7 @@ void __init sched_init_smp(void)
#endif
get_online_cpus();
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);
if (cpumask_empty(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),
GFP_KERNEL, cpu_to_node(i));
if (!se)
- goto err;
+ goto err_free_rq;
init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]);
}
return 1;
+ err_free_rq:
+ kfree(cfs_rq);
err:
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),
GFP_KERNEL, cpu_to_node(i));
if (!rt_se)
- goto err;
+ goto err_free_rq;
init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]);
}
return 1;
+ err_free_rq:
+ kfree(rt_rq);
err:
return 0;
}