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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 30487C7618B for ; Mon, 29 Jul 2019 09:25:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0F9DB2073F for ; Mon, 29 Jul 2019 09:25:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727854AbfG2JZY (ORCPT ); Mon, 29 Jul 2019 05:25:24 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:41444 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726953AbfG2JZY (ORCPT ); Mon, 29 Jul 2019 05:25:24 -0400 Received: by mail-wr1-f67.google.com with SMTP id c2so57791929wrm.8 for ; Mon, 29 Jul 2019 02:25:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=t7Ljxs1sr+mBG3FK3SDP9+7VPp2LGRP4yoTIBN6DoFw=; b=UgGmIZZd9vmohlyaMa0uRas6bzxJAWIEEcxnvY5FaG3LM4U1O0iFarGrhM1Er7Iwk8 3lQtTswQLzl6AOBftFXlTwS4sP1xPt8pq6T+7l8cj4sIzUWZd27g75tcehWXqNskhVF6 Jp+ndpLv3HrJajy3kJyPTPAHQnOUUxp9EFR/tu3jAA5LcEzBtpucejPGzP0qxP82ufaA DY5xDLDrIjpkxNIUilKw+Ae0qogeQJY2oKxcu6iJ1gdSqRuieO4yxWcQ9d6tHHKfoPoY q/cRoxqeGkDRrChhf5azr2w3lrFB91n3Dla82+pl9TjSVWG+4nZsFVK8+yRFfqMpzRFm j7hg== X-Gm-Message-State: APjAAAX7hkTAN6kvZlJiSavsCr9h0Wfdldoapgj/G7VxVQb1N7LGFqWT 2+DQAcHrV5rtJ2tC70cAi9FPgQ== X-Google-Smtp-Source: APXvYqy7MkKr+ZTqwO7kFcE4Z3A/IxNvxUF25RWjb2Hhy7aqr0zOTJoixXZ2Q+VNrXADTsirAuIGMA== X-Received: by 2002:adf:e444:: with SMTP id t4mr19073195wrm.262.1564392322293; Mon, 29 Jul 2019 02:25:22 -0700 (PDT) Received: from localhost.localdomain ([151.29.237.107]) by smtp.gmail.com with ESMTPSA id j16sm1882024wrp.62.2019.07.29.02.25.21 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 29 Jul 2019 02:25:21 -0700 (PDT) Date: Mon, 29 Jul 2019 11:25:19 +0200 From: Juri Lelli To: Peter Zijlstra Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, luca.abeni@santannapisa.it, bristot@redhat.com, balsini@android.com, dvyukov@google.com, tglx@linutronix.de, vpillai@digitalocean.com, rostedt@goodmis.org Subject: Re: [RFC][PATCH 04/13] sched/{rt,deadline}: Fix set_next_task vs pick_next_task Message-ID: <20190729092519.GR25636@localhost.localdomain> References: <20190726145409.947503076@infradead.org> <20190726161357.579899041@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190726161357.579899041@infradead.org> User-Agent: Mutt/1.11.3 (2019-02-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 26/07/19 16:54, Peter Zijlstra wrote: > Because pick_next_task() implies set_curr_task() and some of the > details haven't matter too much, some of what _should_ be in > set_curr_task() ended up in pick_next_task, correct this. > > This prepares the way for a pick_next_task() variant that does not > affect the current state; allowing remote picking. > > Signed-off-by: Peter Zijlstra (Intel) > --- > kernel/sched/deadline.c | 23 ++++++++++++----------- > kernel/sched/rt.c | 27 ++++++++++++++------------- > 2 files changed, 26 insertions(+), 24 deletions(-) > > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -1694,12 +1694,21 @@ static void start_hrtick_dl(struct rq *r > } > #endif > > -static inline void set_next_task(struct rq *rq, struct task_struct *p) > +static void set_next_task_dl(struct rq *rq, struct task_struct *p) > { > p->se.exec_start = rq_clock_task(rq); > > /* You can't push away the running task */ > dequeue_pushable_dl_task(rq, p); > + > + if (hrtick_enabled(rq)) > + start_hrtick_dl(rq, p); > + > + if (rq->curr->sched_class != &dl_sched_class) > + update_dl_rq_load_avg(rq_clock_pelt(rq), rq, 0); > + > + if (rq->curr != p) > + deadline_queue_push_tasks(rq); It's a minor thing, but I was wondering why you added the check on curr. deadline_queue_push_tasks() already checks if are there pushable tasks, plus curr can still be of a different class at this point? Thanks, Juri