[tip:sched/core] cpuidle: Use wake_up_all_idle_cpus() to wake up all idle cpus

[tip-bot for Chuansheng Liu]

Commit-ID:  2ed903c5485bad0eafdd3d59ff993598736e4f31
Gitweb:     http://git.kernel.org/tip/2ed903c5485bad0eafdd3d59ff993598736e4f31
Author:     Chuansheng Liu <chuansheng.liu@xxxxxxxxx>
AuthorDate: Thu, 4 Sep 2014 15:17:55 +0800
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Cc: changcheng.liu@xxxxxxxxx
Cc: xiaoming.wang@xxxxxxxxx
Cc: souvik.k.chakravarty@xxxxxxxxx
Cc: luto@xxxxxxxxxxxxxx
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: linux-pm@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/1409815075-4180-3-git-send-email-chuansheng.liu@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 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;
 }
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/