Commit-ID: c444117f0f39d59733ec23da67c44424df529230 Gitweb: http://git.kernel.org/tip/c444117f0f39d59733ec23da67c44424df529230 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Fri, 11 Apr 2014 13:47:16 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Thu, 8 May 2014 09:16:58 +0200
sched/idle: Delay clearing the polling bit With the generic idle functions assuming !polling we should only clear the polling bit at the very last opportunity in order to avoid spurious IPIs. Ideally we'd flip the default to polling, but that means auditing all arch idle functions. Signed-off-by: Peter Zijlstra <pet...@infradead.org> Acked-by: Nicolas Pitre <nicolas.pi...@linaro.org> Cc: Daniel Lezcano <daniel.lezc...@linaro.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-vq7719foqzf6z5h4j7eh7...@git.kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/idle.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 8f4390a..ed67f0c 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -78,12 +78,10 @@ static int cpuidle_idle_call(void) /* * Check if the idle task must be rescheduled. If it is the - * case, exit the function after re-enabling the local irq and - * set again the polling flag + * case, exit the function after re-enabling the local irq. */ - if (current_clr_polling_and_test()) { + if (need_resched()) { local_irq_enable(); - __current_set_polling(); return 0; } @@ -127,7 +125,7 @@ static int cpuidle_idle_call(void) broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP); - if (broadcast) + if (broadcast) { /* * Tell the time framework to switch * to a broadcast timer because our @@ -139,6 +137,7 @@ static int cpuidle_idle_call(void) ret = clockevents_notify( CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); + } if (!ret) { trace_cpu_idle_rcuidle(next_state, dev->cpu); @@ -175,8 +174,12 @@ static int cpuidle_idle_call(void) * We can't use the cpuidle framework, let's use the default * idle routine */ - if (ret) - arch_cpu_idle(); + if (ret) { + if (!current_clr_polling_and_test()) + arch_cpu_idle(); + else + local_irq_enable(); + } __current_set_polling(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
