From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755075Ab3AEIhm (ORCPT ); Sat, 5 Jan 2013 03:37:42 -0500 Received: from mga11.intel.com ([192.55.52.93]:44979 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755344Ab3AEIhU (ORCPT ); Sat, 5 Jan 2013 03:37:20 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,415,1355126400"; d="scan'208";a="270210077" From: Alex Shi To: mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, akpm@linux-foundation.org, arjan@linux.intel.com, bp@alien8.de, pjt@google.com, namhyung@kernel.org, efault@gmx.de Cc: vincent.guittot@linaro.org, gregkh@linuxfoundation.org, preeti@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, alex.shi@intel.com Subject: [PATCH v3 07/22] sched: set initial load avg of new forked task Date: Sat, 5 Jan 2013 16:37:36 +0800 Message-Id: <1357375071-11793-8-git-send-email-alex.shi@intel.com> X-Mailer: git-send-email 1.7.12 In-Reply-To: <1357375071-11793-1-git-send-email-alex.shi@intel.com> References: <1357375071-11793-1-git-send-email-alex.shi@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org New task has no runnable sum at its first runnable time, that make burst forking just select few idle cpus to put tasks. Set initial load avg of new forked task as its load weight to resolve this issue. Signed-off-by: Alex Shi --- include/linux/sched.h | 1 + kernel/sched/core.c | 2 +- kernel/sched/fair.c | 11 +++++++++-- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 206bb08..fb7aab5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1069,6 +1069,7 @@ struct sched_domain; #else #define ENQUEUE_WAKING 0 #endif +#define ENQUEUE_NEWTASK 8 #define DEQUEUE_SLEEP 1 diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 66c1718..66ce1f1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1705,7 +1705,7 @@ void wake_up_new_task(struct task_struct *p) #endif rq = __task_rq_lock(p); - activate_task(rq, p, 0); + activate_task(rq, p, ENQUEUE_NEWTASK); p->on_rq = 1; trace_sched_wakeup_new(p, true); check_preempt_curr(rq, p, WF_FORK); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 895a3f4..5c545e4 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1503,8 +1503,9 @@ static inline void update_rq_runnable_avg(struct rq *rq, int runnable) /* Add the load generated by se into cfs_rq's child load-average */ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se, - int wakeup) + int flags) { + int wakeup = flags & ENQUEUE_WAKEUP; /* * We track migrations using entity decay_count <= 0, on a wake-up * migration we use a negative decay count to track the remote decays @@ -1538,6 +1539,12 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, update_entity_load_avg(se, 0); } + /* + * set the initial load avg of new task same as its load + * in order to avoid brust fork make few cpu too heavier + */ + if (flags & ENQUEUE_NEWTASK) + se->avg.load_avg_contrib = se->load.weight; cfs_rq->runnable_load_avg += se->avg.load_avg_contrib; /* we force update consideration on load-balancer moves */ update_cfs_rq_blocked_load(cfs_rq, !wakeup); @@ -1701,7 +1708,7 @@ enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) * Update run-time statistics of the 'current'. */ update_curr(cfs_rq); - enqueue_entity_load_avg(cfs_rq, se, flags & ENQUEUE_WAKEUP); + enqueue_entity_load_avg(cfs_rq, se, flags); account_entity_enqueue(cfs_rq, se); update_cfs_shares(cfs_rq); -- 1.7.12