[GIT PULL] scheduler fixes

Ingo Molnar
2009-08-04T19:07:38Z

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

------------------>
Gregory Haskins (1):
sched: Fix race in cpupri introduced by cpumask_var changes

Peter Zijlstra (1):
sched: Fix latencytop and sleep profiling vs group scheduling

kernel/sched_cpupri.c | 15 ++++++++++++++-
kernel/sched_fair.c | 32 +++++++++++++++++++-------------
2 files changed, 33 insertions(+), 14 deletions(-)

diff --git a/kernel/sched_cpupri.c b/kernel/sched_cpupri.c
index e6c2517..d014efb 100644
--- a/kernel/sched_cpupri.c
+++ b/kernel/sched_cpupri.c
@@ -81,8 +81,21 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
if (cpumask_any_and(&p->cpus_allowed, vec->mask) >= nr_cpu_ids)
continue;

- if (lowest_mask)
+ if (lowest_mask) {
cpumask_and(lowest_mask, &p->cpus_allowed, vec->mask);
+
+ /*
+ * We have to ensure that we have at least one bit
+ * still set in the array, since the map could have
+ * been concurrently emptied between the first and
+ * second reads of vec->mask. If we hit this
+ * condition, simply act as though we never hit this
+ * priority level and continue on.
+ */
+ if (cpumask_any(lowest_mask) >= nr_cpu_ids)
+ continue;
+ }
+
return 1;
}

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 9ffb2b2..652e8bd 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -611,9 +611,13 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
#ifdef CONFIG_SCHEDSTATS
+ struct task_struct *tsk = NULL;
+
+ if (entity_is_task(se))
+ tsk = task_of(se);
+
if (se->sleep_start) {
u64 delta = rq_of(cfs_rq)->clock - se->sleep_start;
- struct task_struct *tsk = task_of(se);

if ((s64)delta < 0)
delta = 0;
@@ -624,11 +628,11 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->sleep_start = 0;
se->sum_sleep_runtime += delta;

- account_scheduler_latency(tsk, delta >> 10, 1);
+ if (tsk)
+ account_scheduler_latency(tsk, delta >> 10, 1);
}
if (se->block_start) {
u64 delta = rq_of(cfs_rq)->clock - se->block_start;
- struct task_struct *tsk = task_of(se);

if ((s64)delta < 0)
delta = 0;
@@ -639,17 +643,19 @@ static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
se->block_start = 0;
se->sum_sleep_runtime += delta;

- /*
- * Blocking time is in units of nanosecs, so shift by 20 to
- * get a milliseconds-range estimation of the amount of
- * time that the task spent sleeping:
- */
- if (unlikely(prof_on == SLEEP_PROFILING)) {
-
- profile_hits(SLEEP_PROFILING, (void *)get_wchan(tsk),
- delta >> 20);
+ if (tsk) {
+ /*
+ * Blocking time is in units of nanosecs, so shift by
+ * 20 to get a milliseconds-range estimation of the
+ * amount of time that the task spent sleeping:
+ */
+ if (unlikely(prof_on == SLEEP_PROFILING)) {
+ profile_hits(SLEEP_PROFILING,
+ (void *)get_wchan(tsk),
+ delta >> 20);
+ }
+ account_scheduler_latency(tsk, delta >> 10, 0);
}
- account_scheduler_latency(tsk, delta >> 10, 0);
}
#endif
}