Commit-ID: 970892a9031a5dc7217bd394fb9d89fa75a4a7bc
Gitweb: http://git.kernel.org/tip/970892a9031a5dc7217bd394fb9d89fa75a4a7bc
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Thu, 13 Aug 2009 11:47:54 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 13 Aug 2009 12:58:05 +0200
perf_counter: Fix an ipi-deadlock
perf_pending_counter() is called from IRQ context and will call
perf_counter_disable(), however perf_counter_disable() uses
smp_call_function_single() which doesn't fancy being used with
IRQs disabled due to IPI deadlocks.
Fix this by making it use the local __perf_counter_disable()
call and teaching the counter_sched_out() code about pending
disables as well.
This should cover the case where a counter migrates before the
pending queue gets processed.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Corey J Ashford <cjashfor@xxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: stephane eranian <eranian@xxxxxxxxxxxxxx>
LKML-Reference: <20090813103655.244097721@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/perf_counter.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletions(-)
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index b8c6b97..3f841be 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -307,6 +307,10 @@ counter_sched_out(struct perf_counter *counter,
return;
counter->state = PERF_COUNTER_STATE_INACTIVE;
+ if (counter->pending_disable) {
+ counter->pending_disable = 0;
+ counter->state = PERF_COUNTER_STATE_OFF;
+ }
counter->tstamp_stopped = ctx->time;
counter->pmu->disable(counter);
counter->oncpu = -1;
@@ -2343,7 +2347,7 @@ static void perf_pending_counter(struct perf_pending_entry *entry)
if (counter->pending_disable) {
counter->pending_disable = 0;
- perf_counter_disable(counter);
+ __perf_counter_disable(counter);
}
if (counter->pending_wakeup) {
--
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