diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-09-02 14:29:27 +0200 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2011-12-28 16:25:41 -0600 |
| commit | 451eaac260e6e09a46cd9839d21da09e5eaa1d62 (patch) | |
| tree | 39d0dfcc06288375dbb98b31f495c5aaef820700 /kernel | |
| parent | 5d09fe46492b221099ae56eb7d0673b3e9b29b9e (diff) | |
sched: teach migrate_disable about atomic contexts
<NMI> [<ffffffff812dafd8>] spin_bug+0x94/0xa8
[<ffffffff812db07f>] do_raw_spin_lock+0x43/0xea
[<ffffffff814fa9be>] _raw_spin_lock_irqsave+0x6b/0x85
[<ffffffff8106ff9e>] ? migrate_disable+0x75/0x12d
[<ffffffff81078aaf>] ? pin_current_cpu+0x36/0xb0
[<ffffffff8106ff9e>] migrate_disable+0x75/0x12d
[<ffffffff81115b9d>] pagefault_disable+0xe/0x1f
[<ffffffff81047027>] copy_from_user_nmi+0x74/0xe6
[<ffffffff810489d7>] perf_callchain_user+0xf3/0x135
Now clearly we can't go around taking locks from NMI context, cure
this by short-circuiting migrate_disable() when we're in an atomic
context already.
Add some extra debugging to avoid things like:
preempt_disable()
migrate_disable();
preempt_enable();
migrate_enable();
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1314967297.1301.14.camel@twins
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-wbot4vsmwhi8vmbf83hsclk6@git.kernel.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 3baf3de6de8e..c26b1bac7fb6 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6307,6 +6307,17 @@ void migrate_disable(void) unsigned long flags; struct rq *rq; + if (in_atomic()) { +#ifdef CONFIG_SCHED_DEBUG + p->migrate_disable_atomic++; +#endif + return; + } + +#ifdef CONFIG_SCHED_DEBUG + WARN_ON_ONCE(p->migrate_disable_atomic); +#endif + preempt_disable(); if (p->migrate_disable) { p->migrate_disable++; @@ -6355,6 +6366,16 @@ void migrate_enable(void) unsigned long flags; struct rq *rq; + if (in_atomic()) { +#ifdef CONFIG_SCHED_DEBUG + p->migrate_disable_atomic--; +#endif + return; + } + +#ifdef CONFIG_SCHED_DEBUG + WARN_ON_ONCE(p->migrate_disable_atomic); +#endif WARN_ON_ONCE(p->migrate_disable <= 0); preempt_disable(); |