Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755676Ab2BGChF (ORCPT ); Mon, 6 Feb 2012 21:37:05 -0500 Received: from e23smtp09.au.ibm.com ([202.81.31.142]:54377 "EHLO e23smtp09.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755447Ab2BGChD (ORCPT ); Mon, 6 Feb 2012 21:37:03 -0500 Message-ID: <4F308E25.7060101@linux.vnet.ibm.com> Date: Tue, 07 Feb 2012 10:36:21 +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: [PATCH v2] Avoid unnecessary work in reweight_entity References: <4F2F9F6C.1090608@linux.vnet.ibm.com> <4F3089F9.6010609@linux.vnet.ibm.com> In-Reply-To: <4F3089F9.6010609@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12020617-3568-0000-0000-0000012C4BE7 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3075 Lines: 108 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. Because there are no really enqueue and dequeue happen here, it is also 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. 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..050d66b 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)->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/