path: root/arch/x86
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authorPeter Zijlstra <peterz@infradead.org>2013-09-11 12:43:13 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-29 11:11:42 -0800
commite895dad0a5b1db5475346d9c2ae4a92e6fefa58d (patch)
tree5a1333b355a74c688a911fb2926c127236b55cef /arch/x86
parent5bad04d7bc7fe12a89b716f8b63d32b5735f6dd2 (diff)
sched, idle: Fix the idle polling state logic
commit ea8117478918a4734586d35ff530721b682425be upstream. Mike reported that commit 7d1a9417 ("x86: Use generic idle loop") regressed several workloads and caused excessive reschedule interrupts. The patch in question failed to notice that the x86 code had an inverted sense of the polling state versus the new generic code (x86: default polling, generic: default !polling). Fix the two prominent x86 mwait based idle drivers and introduce a few new generic polling helpers (fixing the wrong smp_mb__after_clear_bit usage). Also switch the idle routines to using tif_need_resched() which is an immediate TIF_NEED_RESCHED test as opposed to need_resched which will end up being slightly different. Reported-by: Mike Galbraith <bitbucket@online.de> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: lenb@kernel.org Cc: tglx@linutronix.de Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/x86')
1 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 81a5f5e8f14..59b90379cb6 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -391,9 +391,9 @@ static void amd_e400_idle(void)
* The switch back from broadcast mode needs to be
* called with interrupts disabled.
- local_irq_disable();
- clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
- local_irq_enable();
+ local_irq_disable();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+ local_irq_enable();
} else