Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751708Ab2BPOOm (ORCPT ); Thu, 16 Feb 2012 09:14:42 -0500 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:50655 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750906Ab2BPOOl (ORCPT ); Thu, 16 Feb 2012 09:14:41 -0500 Message-ID: <4F3D0F41.1010205@linux.vnet.ibm.com> Date: Thu, 16 Feb 2012 22:14:25 +0800 From: Michael Wang User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.26) Gecko/20120131 Thunderbird/3.1.18 MIME-Version: 1.0 To: Peter Zijlstra , Ingo Molnar CC: LKML Subject: [PATCH v4] sched: Avoid unnecessary work in reweight_entity References: <4F2F9F6C.1090608@linux.vnet.ibm.com> <4F3089F9.6010609@linux.vnet.ibm.com> <4F308E25.7060101@linux.vnet.ibm.com> <4F31D9B2.5090501@linux.vnet.ibm.com> In-Reply-To: <4F31D9B2.5090501@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12021604-0260-0000-0000-0000008CE20C Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3364 Lines: 116 From: Michael Wang In original code, using account_entity_dequeue and account_entity_enqueue as a pair will do some work unnecessary, such like remove node from list and add it back again immediately. And because there are no really enqueue and dequeue happen here, it is not suitable to use account_entity_dequeue and account_entity_enqueue here. This patch combine the work of them in order to save time. v2: Add more description and revise wrong code. v3: Mark add_cfs_task_weight and sub_add_cfs_task_weight as inline. v4: Now we invoke update_curr when really necessary. Signed-off-by: Michael Wang --- kernel/sched/fair.c | 27 +++++++++++++++++++++------ kernel/sched/sched.h | 8 ++++++++ 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 7c6414f..fda63ec 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -777,16 +777,28 @@ update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se) */ #if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED -static void +static inline void add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight) { cfs_rq->task_weight += weight; } + +static inline 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 inline void +sub_add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long sub, unsigned long add) +{ +} #endif static void @@ -938,6 +950,7 @@ 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) { @@ -945,13 +958,15 @@ static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, /* 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)->load, se->load.weight, weight); + } + 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; -- 1.7.4.1 -- 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/