[PATCH] x86_64: move out tick_nohz_stop_sched_tick() call from the loop

[PATCH] x86_64: move out tick_nohz_stop_sched_tick() call from the loop

[Hiroshi Shimamoto]

Hello,

tick_nohz_stop_sched_tick() and tick_nohz_restart_sched_tick()
pair in cpu_idle() is different from 32-bit version.

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Subject: [PATCH] x86_64: move out tick_nohz_stop_sched_tick() call from the loop

Move out tick_nohz_stop_sched_tick() call from the loop in cpu_idle
same as 32-bit version.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/kernel/process_64.c |    3 +--
 1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 93ce4f3..6870208 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -170,14 +170,13 @@ void cpu_idle(void)
 	current_thread_info()->status |= TS_POLLING;
 	/* endless idle loop with no priority at all */
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		while (!need_resched()) {
 			void (*idle)(void);
 
 			if (__get_cpu_var(cpu_idle_state))
 				__get_cpu_var(cpu_idle_state) = 0;
 
-			tick_nohz_stop_sched_tick();
-
 			rmb();
 			idle = pm_idle;
 			if (!idle)
-- 
1.5.3.6

Re: [PATCH] x86_64: move out tick_nohz_stop_sched_tick() call from the loop

[Ingo Molnar]

* Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> wrote:

> @@ -170,14 +170,13 @@ void cpu_idle(void)
>  	current_thread_info()->status |= TS_POLLING;
>  	/* endless idle loop with no priority at all */
>  	while (1) {
> +		tick_nohz_stop_sched_tick();
>  		while (!need_resched()) {
>  			void (*idle)(void);
>  
>  			if (__get_cpu_var(cpu_idle_state))
>  				__get_cpu_var(cpu_idle_state) = 0;
>  
> -			tick_nohz_stop_sched_tick();
> -

thanks, applied.

	Ingo