From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752782AbaCFJcJ (ORCPT ); Thu, 6 Mar 2014 04:32:09 -0500 Received: from relay.parallels.com ([195.214.232.42]:54850 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752247AbaCFJcF (ORCPT ); Thu, 6 Mar 2014 04:32:05 -0500 Message-ID: <1394098315.19290.10.camel@tkhai> Subject: [PATCH tip 1/2] sched/fair: Push down check for high priority class task into idle_balance() From: Kirill Tkhai To: CC: Peter Zijlstra , Ingo Molnar Date: Thu, 6 Mar 2014 13:31:55 +0400 Organization: Parallels Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.8.5-2+b1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Originating-IP: [10.30.26.172] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We close idle_exit_fair() bracket in case of we've pulled something or we've received task of high priority class. Signed-off-by: Kirill Tkhai CC: Peter Zijlstra CC: Ingo Molnar --- kernel/sched/fair.c | 15 ++++++++++----- kernel/sched/idle_task.c | 1 - 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index d8482e1..b956e70 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4787,17 +4787,16 @@ simple: return p; idle: + new_tasks = idle_balance(rq); /* * Because idle_balance() releases (and re-acquires) rq->lock, it is * possible for any higher priority task to appear. In that case we * must re-start the pick_next_entity() loop. */ - new_tasks = idle_balance(rq); - - if (rq->nr_running != rq->cfs.h_nr_running) + if (new_tasks < 0) return RETRY_TASK; - if (new_tasks) + if (new_tasks > 0) goto again; return NULL; @@ -6728,8 +6727,14 @@ static int idle_balance(struct rq *this_rq) this_rq->max_idle_balance_cost = curr_cost; out: - if (pulled_task) + /* Is there a task of a high priority class? */ + if (this_rq->nr_running != this_rq->cfs.h_nr_running) + pulled_task = -1; + + if (pulled_task) { + idle_exit_fair(this_rq); this_rq->idle_stamp = 0; + } return pulled_task; } diff --git a/kernel/sched/idle_task.c b/kernel/sched/idle_task.c index 1f37258..879f2b7 100644 --- a/kernel/sched/idle_task.c +++ b/kernel/sched/idle_task.c @@ -29,7 +29,6 @@ pick_next_task_idle(struct rq *rq, struct task_struct *prev) put_prev_task(rq, prev); schedstat_inc(rq, sched_goidle); - idle_enter_fair(rq); return rq->idle; }