From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B1F9C3F2D2 for ; Mon, 2 Mar 2020 13:27:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28F4F2086A for ; Mon, 2 Mar 2020 13:27:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728030AbgCBN1q (ORCPT ); Mon, 2 Mar 2020 08:27:46 -0500 Received: from foss.arm.com ([217.140.110.172]:60880 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728010AbgCBN1m (ORCPT ); Mon, 2 Mar 2020 08:27:42 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6E6E8106F; Mon, 2 Mar 2020 05:27:42 -0800 (PST) Received: from e107158-lin.cambridge.arm.com (e107158-lin.cambridge.arm.com [10.1.195.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 056013F534; Mon, 2 Mar 2020 05:27:40 -0800 (PST) From: Qais Yousef To: Ingo Molnar , Peter Zijlstra , Steven Rostedt , Dietmar Eggemann , Pavan Kondeti Cc: Juri Lelli , Vincent Guittot , Ben Segall , Mel Gorman , linux-kernel@vger.kernel.org, Qais Yousef Subject: [PATCH v3 4/6] sched/rt: Allow pulling unfitting task Date: Mon, 2 Mar 2020 13:27:19 +0000 Message-Id: <20200302132721.8353-5-qais.yousef@arm.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200302132721.8353-1-qais.yousef@arm.com> References: <20200302132721.8353-1-qais.yousef@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When implemented RT Capacity Awareness; the logic was done such that if a task was running on a fitting CPU, then it was sticky and we would try our best to keep it there. But as Steve suggested, to adhere to the strict priority rules of RT class; allow pulling an RT task to unfitting CPU to ensure it gets a chance to run ASAP. Suggested-by: Steven Rostedt Fixes: 804d402fb6f6 ("sched/rt: Make RT capacity-aware") LINK: https://lore.kernel.org/lkml/20200203111451.0d1da58f@oasis.local.home/ Signed-off-by: Qais Yousef --- kernel/sched/rt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index 3071c8612c03..e79a23ad4a93 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1656,8 +1656,7 @@ static void put_prev_task_rt(struct rq *rq, struct task_struct *p) static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu) { if (!task_running(rq, p) && - cpumask_test_cpu(cpu, p->cpus_ptr) && - rt_task_fits_capacity(p, cpu)) + cpumask_test_cpu(cpu, p->cpus_ptr)) return 1; return 0; -- 2.17.1