Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755530Ab2BGCSr (ORCPT ); Mon, 6 Feb 2012 21:18:47 -0500 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:38843 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755211Ab2BGCSq (ORCPT ); Mon, 6 Feb 2012 21:18:46 -0500 Message-ID: <4F3089F9.6010609@linux.vnet.ibm.com> Date: Tue, 07 Feb 2012 10:18:33 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.24) Gecko/20111108 Thunderbird/3.1.16 MIME-Version: 1.0 To: Peter Zijlstra , Ingo Molnar CC: LKML Subject: Re: [PATCH] sched: Avoid unnecessary work in reweight_entity References: <4F2F9F6C.1090608@linux.vnet.ibm.com> In-Reply-To: <4F2F9F6C.1090608@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12020616-5490-0000-0000-000000B042A4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3127 Lines: 108 On 02/06/2012 05:37 PM, Michael Wang wrote: > From: Michael Wang > > In original code, using account_entity_dequeue and account_entity_enqueue > as a pair will do some work unnecessary, this patch combine the work of > them to save time. > > Signed-off-by: Michael Wang > --- > kernel/sched/fair.c | 32 ++++++++++++++++++++++++-------- > kernel/sched/sched.h | 8 ++++++++ > 2 files changed, 32 insertions(+), 8 deletions(-) > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index 84adb2d..e380518 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -782,11 +782,23 @@ add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) > { > cfs_rq->task_weight += weight; > } > + > +static void > +sub_add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long sub, unsigned long add) > +{ > + cfs_rq->task_weight -= sub; > + cfs_rq->task_weight += add; > +} > #else > static inline void > add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) > { > } > + > +static void > +sub_add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long sub, unsigned long add) > +{ > +} > #endif > > static void > @@ -938,20 +950,24 @@ static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq) > { > } > # endif /* CONFIG_SMP */ > + > static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, > unsigned long weight) > { > + /* commit outstanding execution time */ > + if (cfs_rq->curr == se) > + update_curr(cfs_rq); > + > if (se->on_rq) { > - /* commit outstanding execution time */ > - if (cfs_rq->curr == se) > - update_curr(cfs_rq); > - account_entity_dequeue(cfs_rq, se); > + update_load_sub_add(&cfs_rq->load, se->load.weight, weight); > + if (!parent_entity(se)) { > + update_load_sub_add(&rq_of(cfs_rq), se->load.weight, weight); Sorry for make a silly mistake here, should try make first, I will sent correct patch soon. Regards, Michael Wang > + } > + if (entity_is_task(se)) { > + sub_add_cfs_task_weight(cfs_rq, se->load.weight, weight); > + } > } > - > update_load_set(&se->load, weight); > - > - if (se->on_rq) > - account_entity_enqueue(cfs_rq, se); > } > > static void update_cfs_shares(struct cfs_rq *cfs_rq) > diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h > index 98c0c26..ec4430f 100644 > --- a/kernel/sched/sched.h > +++ b/kernel/sched/sched.h > @@ -779,6 +779,14 @@ static inline void update_load_sub(struct load_weight *lw, unsigned long dec) > lw->inv_weight = 0; > } > > +static inline void update_load_sub_add(struct load_weight *lw, unsigned long dec, > + unsigned long inc) > +{ > + lw->weight -= dec; > + lw->weight += inc; > + lw->inv_weight = 0; > +} > + > static inline void update_load_set(struct load_weight *lw, unsigned long w) > { > lw->weight = w; -- 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/