Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757375Ab3CSFPM (ORCPT ); Tue, 19 Mar 2013 01:15:12 -0400 Received: from mail-oa0-f52.google.com ([209.85.219.52]:65288 "EHLO mail-oa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753767Ab3CSFPJ (ORCPT ); Tue, 19 Mar 2013 01:15:09 -0400 MIME-Version: 1.0 In-Reply-To: References: <9f0fd16f792b9f9b399a4c91c98de37c56067d47.1363617402.git.viresh.kumar@linaro.org> Date: Tue, 19 Mar 2013 10:45:07 +0530 Message-ID: Subject: Re: [PATCH V3 1/7] sched: Create sched_select_cpu() to give preferred CPU for power saving From: Viresh Kumar To: Frederic Weisbecker Cc: pjt@google.com, paul.mckenney@linaro.org, tglx@linutronix.de, tj@kernel.org, suresh.b.siddha@intel.com, venki@google.com, mingo@redhat.com, peterz@infradead.org, rostedt@goodmis.org, linaro-kernel@lists.linaro.org, robin.randhawa@arm.com, Steve.Bannister@arm.com, Liviu.Dudau@arm.com, charles.garcia-tobin@arm.com, Arvind.Chauhan@arm.com, linux-rt-users@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3189 Lines: 90 On 18 March 2013 21:27, Frederic Weisbecker wrote: > 2013/3/18 Viresh Kumar : >>> It would be nice to have some more precise naming. sched_select_busy_cpu() ? >> >> You are correct that name can be improved but busy may give it a different >> meaning. Maybe sched_select_non_idle_cpu()? > > That works too yeah. Here is the fixup that i applied (it fixes another stupid mistake in sched.h). I have pushed this series here again: http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/sched-wq-migration-v3 commit e769ff0d78fd2fb504ae056a44b70bba7c259126 Author: Viresh Kumar Date: Fri Sep 14 15:13:05 2012 +0530 fixup! sched: Create sched_select_cpu() to give preferred CPU for power saving Signed-off-by: Viresh Kumar --- include/linux/sched.h | 19 ++++++++++--------- kernel/sched/core.c | 2 +- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 216fa0d..db6655a 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -231,11 +231,18 @@ extern void init_idle_bootup_task(struct task_struct *idle); extern int runqueue_is_locked(int cpu); #ifdef CONFIG_SMP -extern int sched_select_cpu(unsigned int sd_flags); +extern int sched_select_non_idle_cpu(unsigned int sd_flags); +#else +static inline int sched_select_non_idle_cpu(unsigned int sd_flags) +{ + return smp_processor_id(); +} +#endif -#ifdef CONFIG_NO_HZ +#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ) extern void nohz_balance_enter_idle(int cpu); extern void set_cpu_sd_state_idle(void); + /* * In the semi idle case, use the nearest busy cpu for migrating timers * from an idle cpu. This is good for power-savings. @@ -244,17 +251,11 @@ extern void set_cpu_sd_state_idle(void); * selecting an idle cpu will add more delays to the timers than intended * (as that cpu's timer base may not be uptodate wrt jiffies etc). */ -#define get_nohz_timer_target() sched_select_cpu(0) +#define get_nohz_timer_target() sched_select_non_idle_cpu(0) #else static inline void nohz_balance_enter_idle(int cpu) { } static inline void set_cpu_sd_state_idle(void) { } - -static inline int sched_select_cpu(unsigned int sd_flags) -{ - return raw_smp_processor_id(); -} #endif -#endif /* CONFIG_SMP */ /* * Only dump TASK_* tasks. (0 for all tasks) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ccd76d7..0265a5e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -627,7 +627,7 @@ void sched_avg_update(struct rq *rq) * returned back. If it is idle, then we must look for another CPU which have * all the flags passed as argument as set. */ -int sched_select_cpu(unsigned int sd_flags) +int sched_select_non_idle_cpu(unsigned int sd_flags) { struct sched_domain *sd; int cpu = smp_processor_id(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/