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Subject[tip:sched/core] cpuidle: Use wake_up_all_idle_cpus() to wake up all idle cpus
Commit-ID:  2ed903c5485bad0eafdd3d59ff993598736e4f31
Gitweb: http://git.kernel.org/tip/2ed903c5485bad0eafdd3d59ff993598736e4f31
Author: Chuansheng Liu <chuansheng.liu@intel.com>
AuthorDate: Thu, 4 Sep 2014 15:17:55 +0800
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 19 Sep 2014 12:35:16 +0200

cpuidle: Use wake_up_all_idle_cpus() to wake up all idle cpus

Currently kick_all_cpus_sync() or smp_call_function() can not
break the polling idle cpu immediately.

Instead using wake_up_all_idle_cpus() which can wake up the polling idle
cpu quickly is much more helpful for power.

Signed-off-by: Chuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-pm@vger.kernel.org
Cc: changcheng.liu@intel.com
Cc: xiaoming.wang@intel.com
Cc: souvik.k.chakravarty@intel.com
Cc: luto@amacapital.net
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Link: http://lkml.kernel.org/r/1409815075-4180-3-git-send-email-chuansheng.liu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
drivers/cpuidle/cpuidle.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index ee9df5e..d31e04c 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -223,7 +223,7 @@ void cpuidle_uninstall_idle_handler(void)
{
if (enabled_devices) {
initialized = 0;
- kick_all_cpus_sync();
+ wake_up_all_idle_cpus();
}
}

@@ -530,11 +530,6 @@ EXPORT_SYMBOL_GPL(cpuidle_register);

#ifdef CONFIG_SMP

-static void smp_callback(void *v)
-{
- /* we already woke the CPU up, nothing more to do */
-}
-
/*
* This function gets called when a part of the kernel has a new latency
* requirement. This means we need to get all processors out of their C-state,
@@ -544,7 +539,7 @@ static void smp_callback(void *v)
static int cpuidle_latency_notify(struct notifier_block *b,
unsigned long l, void *v)
{
- smp_call_function(smp_callback, NULL, 1);
+ wake_up_all_idle_cpus();
return NOTIFY_OK;
}


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