linux-kernel - [tip:sched/core] cpuidle: Use wake_up_all_idle

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Date:	Fri, 19 Sep 2014 04:44:13 -0700
From:	tip-bot for Chuansheng Liu <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	torvalds@...ux-foundation.org, peterz@...radead.org,
	tglx@...utronix.de, rjw@...ysocki.net, daniel.lezcano@...aro.org,
	chuansheng.liu@...el.com
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@...el.com>
AuthorDate: Thu, 4 Sep 2014 15:17:55 +0800
Committer:  Ingo Molnar <mingo@...nel.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@...el.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: linux-pm@...r.kernel.org
Cc: changcheng.liu@...el.com
Cc: xiaoming.wang@...el.com
Cc: souvik.k.chakravarty@...el.com
Cc: luto@...capital.net
Cc: Daniel Lezcano <daniel.lezcano@...aro.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Rafael J. Wysocki <rjw@...ysocki.net>
Cc: linux-pm@...r.kernel.org
Link: http://lkml.kernel.org/r/1409815075-4180-3-git-send-email-chuansheng.liu@intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.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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