[PATCH] stop_machine: disable preempt in stop machine path

From: Xiao Guangrong
Date: Wed Sep 16 2009 - 03:27:51 EST


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@xxxxxxxxxxxxxx>
---
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

--
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/