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From: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Rusty Russell <rusty@rustcorp.com.au>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] stop_machine: disable preempt in stop machine path
Date: Wed, 16 Sep 2009 15:26:54 +0800	[thread overview]
Message-ID: <4AB0933E.8020901@cn.fujitsu.com> (raw)

We can disable preempt in stop_cpu(), It can reduce the cpu's waiting time
and make stop_machine path faster.

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
 kernel/stop_machine.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 912823e..feaa947 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -68,7 +68,7 @@ static void stop_cpu(struct work_struct *unused)
 {
 	enum stopmachine_state curstate = STOPMACHINE_NONE;
 	struct stop_machine_data *smdata = &idle;
-	int cpu = smp_processor_id();
+	int cpu = get_cpu();
 	int err;
 
 	if (!active_cpus) {
@@ -103,6 +103,7 @@ static void stop_cpu(struct work_struct *unused)
 		}
 	} while (curstate != STOPMACHINE_EXIT);
 
+	put_cpu();
 	local_irq_enable();
 }
 
-- 
1.6.1.2


             reply	other threads:[~2009-09-16  7:27 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-16  7:26 Xiao Guangrong [this message]
2009-09-16 23:03 ` [PATCH] stop_machine: disable preempt in stop machine path Andrew Morton
2009-09-17  1:23   ` Xiao Guangrong
2009-09-22  5:50 ` Rusty Russell

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