From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH V3 4/7] PHYLIB: queue work on any cpu Date: Mon, 18 Mar 2013 13:33:39 -0400 (EDT) Message-ID: <20130318.133339.2056938599662437643.davem@davemloft.net> References: <9a366f17b93a5e18777360481c94e6db763b45b7.1363617402.git.viresh.kumar@linaro.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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, netdev@vger.kernel.org To: viresh.kumar@linaro.org Return-path: In-Reply-To: <9a366f17b93a5e18777360481c94e6db763b45b7.1363617402.git.viresh.kumar@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Viresh Kumar Date: Mon, 18 Mar 2013 20:53:26 +0530 > Phylib uses workqueues for multiple purposes. There is no real dependency of > scheduling these on the cpu which scheduled them. > > On a idle system, it is observed that and idle cpu wakes up many times just to > service this work. It would be better if we can schedule it on a cpu which isn't > idle to save on power. > > By idle cpu (from scheduler's perspective) we mean: > - Current task is idle task > - nr_running == 0 > - wake_list is empty > > This patch replaces the schedule_work() and schedule_delayed_work() routines > with their queue_[delayed_]work_on_any_cpu() siblings with system_wq as > parameter. > > These routines would look for the closest (via scheduling domains) non-idle cpu > (non-idle from schedulers perspective). If the current cpu is not idle or all > cpus are idle, work will be scheduled on local cpu. > > Cc: "David S. Miller" > Cc: netdev@vger.kernel.org > Signed-off-by: Viresh Kumar This will need to be applied to whatever tree adds these new interfaces, and for that: Acked-by: David S. Miller