Return-Path: Received: from mail-pa0-f68.google.com ([209.85.220.68]:33460 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751589AbcIAHaf (ORCPT ); Thu, 1 Sep 2016 03:30:35 -0400 From: Chunyan Zhang To: trond.myklebust@primarydata.com, anna.schumaker@netapp.com, davem@davemloft.net Cc: linux-nfs@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, zhang.lyra@gmail.com, ke.wang@spreadtrum.com Subject: [PATCH] sunrpc: queue work on system_power_efficient_wq Date: Thu, 1 Sep 2016 15:30:26 +0800 Message-Id: <1472715026-11397-1-git-send-email-zhang.lyra@gmail.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: From: Ke Wang sunrpc uses workqueue to clean cache regulary. There is no real dependency of executing work on the cpu which queueing it. On a idle system, especially for a heterogeneous systems like big.LITTLE, it is observed that the big idle cpu was woke up many times just to service this work, which against the principle of power saving. It would be better if we can schedule it on a cpu which the scheduler believes to be the most appropriate one. After apply this patch, system_wq will be replaced by system_power_efficient_wq for sunrpc. This functionality is enabled when CONFIG_WQ_POWER_EFFICIENT is selected. Signed-off-by: Ke Wang --- net/sunrpc/cache.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 4d8e11f..8aabe12 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -353,7 +353,7 @@ void sunrpc_init_cache_detail(struct cache_detail *cd) spin_unlock(&cache_list_lock); /* start the cleaning process */ - schedule_delayed_work(&cache_cleaner, 0); + queue_delayed_work(system_power_efficient_wq, &cache_cleaner, 0); } EXPORT_SYMBOL_GPL(sunrpc_init_cache_detail); @@ -476,7 +476,8 @@ static void do_cache_clean(struct work_struct *work) delay = 0; if (delay) - schedule_delayed_work(&cache_cleaner, delay); + queue_delayed_work(system_power_efficient_wq, + &cache_cleaner, delay); } -- 2.7.4