diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2009-04-01 18:40:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-07-30 14:39:52 -0700 |
| commit | fedb5937d9f132d3a03b12568925967827335d39 (patch) | |
| tree | 2cafc1de7361c1f8846dba87f112a0c3f422f6ac /kernel | |
| parent | 23e839dc9cad6ea1d74a26abbf8dca6f785ca193 (diff) | |
sched_rt: Fix overload bug on rt group scheduling
commit a1ba4d8ba9f06a397e97cbd67a93ee306860b40a upstream.
Fixes an easily triggerable BUG() when setting process affinities.
Make sure to count the number of migratable tasks in the same place:
the root rt_rq. Otherwise the number doesn't make sense and we'll hit
the BUG in set_cpus_allowed_rt().
Also, make sure we only count tasks, not groups (this is probably
already taken care of by the fact that rt_se->nr_cpus_allowed will be 0
for groups, but be more explicit)
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Gregory Haskins <ghaskins@novell.com>
LKML-Reference: <1247067476.9777.57.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 1 | ||||
| -rw-r--r-- | kernel/sched_rt.c | 18 |
2 files changed, 18 insertions, 1 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 26efa475bdc..0d3d47fe3de 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -497,6 +497,7 @@ struct rt_rq { #endif #ifdef CONFIG_SMP unsigned long rt_nr_migratory; + unsigned long rt_nr_total; int overloaded; struct plist_head pushable_tasks; #endif diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 9bf0d2a7304..3918e01994e 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -10,6 +10,8 @@ static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se) #ifdef CONFIG_RT_GROUP_SCHED +#define rt_entity_is_task(rt_se) (!(rt_se)->my_q) + static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) { return rt_rq->rq; @@ -22,6 +24,8 @@ static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se) #else /* CONFIG_RT_GROUP_SCHED */ +#define rt_entity_is_task(rt_se) (1) + static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq) { return container_of(rt_rq, struct rq, rt); @@ -73,7 +77,7 @@ static inline void rt_clear_overload(struct rq *rq) static void update_rt_migration(struct rt_rq *rt_rq) { - if (rt_rq->rt_nr_migratory && (rt_rq->rt_nr_running > 1)) { + if (rt_rq->rt_nr_migratory && rt_rq->rt_nr_total > 1) { if (!rt_rq->overloaded) { rt_set_overload(rq_of_rt_rq(rt_rq)); rt_rq->overloaded = 1; @@ -86,6 +90,12 @@ static void update_rt_migration(struct rt_rq *rt_rq) static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) { + if (!rt_entity_is_task(rt_se)) + return; + + rt_rq = &rq_of_rt_rq(rt_rq)->rt; + + rt_rq->rt_nr_total++; if (rt_se->nr_cpus_allowed > 1) rt_rq->rt_nr_migratory++; @@ -94,6 +104,12 @@ static void inc_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) static void dec_rt_migration(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) { + if (!rt_entity_is_task(rt_se)) + return; + + rt_rq = &rq_of_rt_rq(rt_rq)->rt; + + rt_rq->rt_nr_total--; if (rt_se->nr_cpus_allowed > 1) rt_rq->rt_nr_migratory--; |