[tip:perf/core] sched/perf: Make sure irqs are disabled for perf_event_task_sched_in()

[tip-bot for Jamie Iles <jamie.iles@picochip.com>]

Commit-ID:  8381f65d097dad90416808314737dd7d3ae38ea9
Gitweb:     http://git.kernel.org/tip/8381f65d097dad90416808314737dd7d3ae38ea9
Author:     Jamie Iles <jamie.iles@picochip.com>
AuthorDate: Fri, 8 Jan 2010 15:27:33 +0000
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Wed, 13 Jan 2010 10:43:08 +0100

sched/perf: Make sure irqs are disabled for perf_event_task_sched_in()

perf_event_task_sched_in() expects interrupts to be disabled,
but on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW
defined, this isn't true. If this is defined, disable irqs
around the call in finish_task_switch().

Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
LKML-Reference: <1262964453-27370-1-git-send-email-jamie.iles@picochip.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/sched.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index e507af0..c3ad342 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2783,7 +2783,13 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev)
 	 */
 	prev_state = prev->state;
 	finish_arch_switch(prev);
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+	local_irq_disable();
+#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
 	perf_event_task_sched_in(current);
+#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
+	local_irq_enable();
+#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */
 	finish_lock_switch(rq, prev);
 
 	fire_sched_in_preempt_notifiers(current);