From ea8117478918a4734586d35ff530721b682425be Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Wed, 11 Sep 2013 12:43:13 +0200 Subject: sched, idle: Fix the idle polling state logic 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 Signed-off-by: Peter Zijlstra Cc: lenb@kernel.org Cc: tglx@linutronix.de Link: http://lkml.kernel.org/n/tip-nc03imb0etuefmzybzj7sprf@git.kernel.org Signed-off-by: Ingo Molnar --- include/linux/thread_info.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/thread_info.h') diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index a629e4b23217..fddbe2023a5d 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -118,6 +118,8 @@ static inline __deprecated void set_need_resched(void) */ } +#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED) + #if defined TIF_RESTORE_SIGMASK && !defined HAVE_SET_RESTORE_SIGMASK /* * An arch can define its own version of set_restore_sigmask() to get the -- cgit v1.2.3