[git pull] scheduler fixes

Ingo Molnar
2008-11-11T18:26:17Z

Linus,

Please pull the latest sched-fixes-for-linus git tree from:

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

Thanks,

Ingo

------------------>
Oleg Nesterov (1):
fix for account_group_exec_runtime(), make sure ->signal can't be freed under rq->lock

Peter Zijlstra (2):
sched: clean up debug info
sched: release buddies on yield

include/linux/sched.h | 1 +
kernel/exit.c | 5 +++++
kernel/sched.c | 10 +++++++++-
kernel/sched_debug.c | 41 +++++++++++++++++++++--------------------
kernel/sched_fair.c | 17 ++++++++++++-----
5 files changed, 48 insertions(+), 26 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 295b7c7..644ffbd 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -247,6 +247,7 @@ extern void init_idle(struct task_struct *idle, int cpu);
extern void init_idle_bootup_task(struct task_struct *idle);

extern int runqueue_is_locked(void);
+extern void task_rq_unlock_wait(struct task_struct *p);

extern cpumask_t nohz_cpu_mask;
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
diff --git a/kernel/exit.c b/kernel/exit.c
index 80137a5..ae2b92b 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -141,6 +141,11 @@ static void __exit_signal(struct task_struct *tsk)
if (sig) {
flush_sigqueue(&sig->shared_pending);
taskstats_tgid_free(sig);
+ /*
+ * Make sure ->signal can't go away under rq->lock,
+ * see account_group_exec_runtime().
+ */
+ task_rq_unlock_wait(tsk);
__cleanup_signal(sig);
}
}
diff --git a/kernel/sched.c b/kernel/sched.c
index 57c933f..50a21f9 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -399,7 +399,7 @@ struct cfs_rq {
*/
struct sched_entity *curr, *next, *last;

- unsigned long nr_spread_over;
+ unsigned int nr_spread_over;

#ifdef CONFIG_FAIR_GROUP_SCHED
struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
@@ -969,6 +969,14 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
}
}

+void task_rq_unlock_wait(struct task_struct *p)
+{
+ struct rq *rq = task_rq(p);
+
+ smp_mb(); /* spin-unlock-wait is not a full memory barrier */
+ spin_unlock_wait(&rq->lock);
+}
+
static void __task_rq_unlock(struct rq *rq)
__releases(rq->lock)
{
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 5ae1776..48ecc51 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -144,7 +144,7 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
last = __pick_last_entity(cfs_rq);
if (last)
max_vruntime = last->vruntime;
- min_vruntime = rq->cfs.min_vruntime;
+ min_vruntime = cfs_rq->min_vruntime;
rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime;
spin_unlock_irqrestore(&rq->lock, flags);
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime",
@@ -161,26 +161,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
SPLIT_NS(spread0));
SEQ_printf(m, " .%-30s: %ld\n", "nr_running", cfs_rq->nr_running);
SEQ_printf(m, " .%-30s: %ld\n", "load", cfs_rq->load.weight);
-#ifdef CONFIG_SCHEDSTATS
-#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
-
- P(yld_exp_empty);
- P(yld_act_empty);
- P(yld_both_empty);
- P(yld_count);

- P(sched_switch);
- P(sched_count);
- P(sched_goidle);
-
- P(ttwu_count);
- P(ttwu_local);
-
- P(bkl_count);
-
-#undef P
-#endif
- SEQ_printf(m, " .%-30s: %ld\n", "nr_spread_over",
+ SEQ_printf(m, " .%-30s: %d\n", "nr_spread_over",
cfs_rq->nr_spread_over);
#ifdef CONFIG_FAIR_GROUP_SCHED
#ifdef CONFIG_SMP
@@ -260,6 +242,25 @@ static void print_cpu(struct seq_file *m, int cpu)
#undef P
#undef PN

+#ifdef CONFIG_SCHEDSTATS
+#define P(n) SEQ_printf(m, " .%-30s: %d\n", #n, rq->n);
+
+ P(yld_exp_empty);
+ P(yld_act_empty);
+ P(yld_both_empty);
+ P(yld_count);
+
+ P(sched_switch);
+ P(sched_count);
+ P(sched_goidle);
+
+ P(ttwu_count);
+ P(ttwu_local);
+
+ P(bkl_count);
+
+#undef P
+#endif
print_cfs_stats(m, cpu);
print_rt_stats(m, cpu);

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 51aa3e1..98345e4 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -716,6 +716,15 @@ 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)
+{
+ if (cfs_rq->last == se)
+ cfs_rq->last = NULL;
+
+ if (cfs_rq->next == se)
+ cfs_rq->next = NULL;
+}
+
static void
dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
{
@@ -738,11 +747,7 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
#endif
}

- if (cfs_rq->last == se)
- cfs_rq->last = NULL;
-
- if (cfs_rq->next == se)
- cfs_rq->next = NULL;
+ clear_buddies(cfs_rq, se);

if (se != cfs_rq->curr)
__dequeue_entity(cfs_rq, se);
@@ -977,6 +982,8 @@ static void yield_task_fair(struct rq *rq)
if (unlikely(cfs_rq->nr_running == 1))
return;

+ clear_buddies(cfs_rq, se);
+
if (likely(!sysctl_sched_compat_yield) && curr->policy != SCHED_BATCH) {
update_rq_clock(rq);
/*