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authorLinus Torvalds <torvalds@linux-foundation.org>2009-02-02 19:26:29 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-02-02 19:26:29 -0800
commit31c952dcf83d5b0fd57b514cbe8a1664647c26e7 (patch)
treefc424cd78e818327a3949c2707c8487506ef1408
parent9e6235e997bf091326b2f3ac92217c2ac2e27eb5 (diff)
parent3d398703ef06fd97b4c28c86b580546d5b57e7b7 (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: sched_rt: don't use first_cpu on cpumask created with cpumask_and sched: fix buddie group latency sched: clear buddies more aggressively sched: symmetric sync vs avg_overlap sched: fix sync wakeups cpuset: fix possible deadlock in async_rebuild_sched_domains
-rw-r--r--kernel/cpuset.c13
-rw-r--r--kernel/sched.c10
-rw-r--r--kernel/sched_fair.c32
-rw-r--r--kernel/sched_rt.c4
4 files changed, 45 insertions, 14 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a85678865c5e..f76db9dcaa05 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -61,6 +61,14 @@
#include <linux/cgroup.h>
/*
+ * Workqueue for cpuset related tasks.
+ *
+ * Using kevent workqueue may cause deadlock when memory_migrate
+ * is set. So we create a separate workqueue thread for cpuset.
+ */
+static struct workqueue_struct *cpuset_wq;
+
+/*
* Tracks how many cpusets are currently defined in system.
* When there is only one cpuset (the root cpuset) we can
* short circuit some hooks.
@@ -831,7 +839,7 @@ static DECLARE_WORK(rebuild_sched_domains_work, do_rebuild_sched_domains);
*/
static void async_rebuild_sched_domains(void)
{
- schedule_work(&rebuild_sched_domains_work);
+ queue_work(cpuset_wq, &rebuild_sched_domains_work);
}
/*
@@ -2111,6 +2119,9 @@ void __init cpuset_init_smp(void)
hotcpu_notifier(cpuset_track_online_cpus, 0);
hotplug_memory_notifier(cpuset_track_online_nodes, 10);
+
+ cpuset_wq = create_singlethread_workqueue("cpuset");
+ BUG_ON(!cpuset_wq);
}
/**
diff --git a/kernel/sched.c b/kernel/sched.c
index 52bbf1c842a8..242d0d47a70d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2266,6 +2266,16 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync)
if (!sched_feat(SYNC_WAKEUPS))
sync = 0;
+ if (!sync) {
+ if (current->se.avg_overlap < sysctl_sched_migration_cost &&
+ p->se.avg_overlap < sysctl_sched_migration_cost)
+ sync = 1;
+ } else {
+ if (current->se.avg_overlap >= sysctl_sched_migration_cost ||
+ p->se.avg_overlap >= sysctl_sched_migration_cost)
+ sync = 0;
+ }
+
#ifdef CONFIG_SMP
if (sched_feat(LB_WAKEUP_UPDATE)) {
struct sched_domain *sd;
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 5cc1c162044f..a7e50ba185ac 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -719,7 +719,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int wakeup)
__enqueue_entity(cfs_rq, se);
}
-static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+static void __clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
if (cfs_rq->last == se)
cfs_rq->last = NULL;
@@ -728,6 +728,12 @@ static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
cfs_rq->next = NULL;
}
+static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+ for_each_sched_entity(se)
+ __clear_buddies(cfs_rq_of(se), se);
+}
+
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -768,8 +774,14 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
ideal_runtime = sched_slice(cfs_rq, curr);
delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
- if (delta_exec > ideal_runtime)
+ if (delta_exec > ideal_runtime) {
resched_task(rq_of(cfs_rq)->curr);
+ /*
+ * The current task ran long enough, ensure it doesn't get
+ * re-elected due to buddy favours.
+ */
+ clear_buddies(cfs_rq, curr);
+ }
}
static void
@@ -1179,20 +1191,15 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
int idx, unsigned long load, unsigned long this_load,
unsigned int imbalance)
{
- struct task_struct *curr = this_rq->curr;
- struct task_group *tg;
unsigned long tl = this_load;
unsigned long tl_per_task;
+ struct task_group *tg;
unsigned long weight;
int balanced;
if (!(this_sd->flags & SD_WAKE_AFFINE) || !sched_feat(AFFINE_WAKEUPS))
return 0;
- if (sync && (curr->se.avg_overlap > sysctl_sched_migration_cost ||
- p->se.avg_overlap > sysctl_sched_migration_cost))
- sync = 0;
-
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
@@ -1419,9 +1426,7 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int sync)
if (!sched_feat(WAKEUP_PREEMPT))
return;
- if (sched_feat(WAKEUP_OVERLAP) && (sync ||
- (se->avg_overlap < sysctl_sched_migration_cost &&
- pse->avg_overlap < sysctl_sched_migration_cost))) {
+ if (sched_feat(WAKEUP_OVERLAP) && sync) {
resched_task(curr);
return;
}
@@ -1452,6 +1457,11 @@ static struct task_struct *pick_next_task_fair(struct rq *rq)
do {
se = pick_next_entity(cfs_rq);
+ /*
+ * If se was a buddy, clear it so that it will have to earn
+ * the favour again.
+ */
+ __clear_buddies(cfs_rq, se);
set_next_entity(cfs_rq, se);
cfs_rq = group_cfs_rq(se);
} while (cfs_rq);
diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 954e1a81b796..bac1061cea2f 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -968,8 +968,8 @@ static inline int pick_optimal_cpu(int this_cpu, cpumask_t *mask)
if ((this_cpu != -1) && cpu_isset(this_cpu, *mask))
return this_cpu;
- first = first_cpu(*mask);
- if (first != NR_CPUS)
+ first = cpumask_first(mask);
+ if (first < nr_cpu_ids)
return first;
return -1;