Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932367AbcDAPS0 (ORCPT ); Fri, 1 Apr 2016 11:18:26 -0400 Received: from mail-wm0-f53.google.com ([74.125.82.53]:34103 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758815AbcDAPSY (ORCPT ); Fri, 1 Apr 2016 11:18:24 -0400 From: Luca Abeni To: linux-kernel@vger.kernel.org Cc: Peter Zijlstra , Ingo Molnar , Juri Lelli , Luca Abeni Subject: [RFC v2 2/7] Correctly track the active utilisation for migrating tasks Date: Fri, 1 Apr 2016 17:12:28 +0200 Message-Id: <1459523553-29089-3-git-send-email-luca.abeni@unitn.it> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1459523553-29089-1-git-send-email-luca.abeni@unitn.it> References: <1459523553-29089-1-git-send-email-luca.abeni@unitn.it> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1433 Lines: 42 Fix active utilisation accounting on migration: when a task is migrated from CPUi to CPUj, immediately subtract the task's utilisation from CPUi and add it to CPUj. This mechanism is implemented by modifying the pull and push functions. Note: this is not fully correct from the theoretical point of view (the utilisation should be removed from CPUi only at the 0 lag time), but doing the right thing would be _MUCH_ more complex (leaving the timer armed when the task is on a different CPU... Inactive timers should be moved from per-task timers to per-runqueue lists of timers! Bah...) Signed-off-by: Luca Abeni --- kernel/sched/deadline.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 3c64ebf..05cfccb 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -1530,7 +1530,9 @@ retry: } deactivate_task(rq, next_task, 0); + sub_running_bw(&next_task->dl, &rq->dl); set_task_cpu(next_task, later_rq->cpu); + add_running_bw(&next_task->dl, &later_rq->dl); activate_task(later_rq, next_task, 0); ret = 1; @@ -1618,7 +1620,9 @@ static void pull_dl_task(struct rq *this_rq) resched = true; deactivate_task(src_rq, p, 0); + sub_running_bw(&p->dl, &src_rq->dl); set_task_cpu(p, this_cpu); + add_running_bw(&p->dl, &this_rq->dl); activate_task(this_rq, p, 0); dmin = p->dl.deadline; -- 2.5.0