diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-02-10 10:23:29 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 15:37:29 -0800 |
| commit | 134f7feec8110044202aa6776f3b700022fe0213 (patch) | |
| tree | fb249769b631631e5dcb1de27f8e5c2f15c29935 /kernel | |
| parent | aa68c0327e866f8c8cdbcea0afa69fcb89ad61a7 (diff) | |
sched: Fix cross-sched-class wakeup preemption
Commit: 1e5a74059f9059d330744eac84873b1b99657008 upstream
Instead of dealing with sched classes inside each check_preempt_curr()
implementation, pull out this logic into the generic wakeup preemption
path.
This fixes a hang in KVM (and others) where we are waiting for the
stop machine thread to run ...
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Marcelo Tosatti <mtosatti@redhat.com>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1288891946.2039.31.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 590d73b793b9..445f2d1101fc 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -594,11 +594,7 @@ struct rq { static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); -static inline -void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) -{ - rq->curr->sched_class->check_preempt_curr(rq, p, flags); -} +static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); static inline int cpu_of(struct rq *rq) { @@ -2392,6 +2388,24 @@ void task_oncpu_function_call(struct task_struct *p, preempt_enable(); } +static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) +{ + const struct sched_class *class; + + if (p->sched_class == rq->curr->sched_class) { + rq->curr->sched_class->check_preempt_curr(rq, p, flags); + } else { + for_each_class(class) { + if (class == rq->curr->sched_class) + break; + if (class == p->sched_class) { + resched_task(rq->curr); + break; + } + } + } +} + #ifdef CONFIG_SMP /* * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. |