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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 EFFB8FA372C for ; Fri, 8 Nov 2019 13:21:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4A1520865 for ; Fri, 8 Nov 2019 13:21:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ifVALW6L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729352AbfKHNVj (ORCPT ); Fri, 8 Nov 2019 08:21:39 -0500 Received: from merlin.infradead.org ([205.233.59.134]:44696 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728366AbfKHNVi (ORCPT ); Fri, 8 Nov 2019 08:21:38 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=X/Vg+fuvXxL5vOt/UuiYkqPDOJfaG5+rXkuRhUYdrco=; b=ifVALW6Lu494H41EmeN/4UwljE WnVmfhefUeG7XOBBpkNF5/nJtZX2DnY7Et92aWUhTqFckal/A/+ydNB1c15R/1qHRqoNesQFzi9JK wYO29YB8hCNXdKNawc/AWAN2yHqxF4/uEmrnVRxrmIpQjiaahkkaJZ8+duuAqF4kEF9aYsC/05rZ9 Lo0ntg6jJGrWTAQZfo6qhAVn2u8gteuNSJ1xwd+8FSiA23mDfU8Rksk0zeeBsePCaH+f5/KX7bC05 Ujgz4EHzZLFSAmj3bJ9SpAyYwYriYxt7P3jYbfqhQhibi9wU8fFgOfwTvaOm+MatscpBs7U2nBfXT BwH9i98g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1iT4CZ-0003ZQ-Bf; Fri, 08 Nov 2019 13:21:23 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5733E301A79; Fri, 8 Nov 2019 14:20:15 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 481FB20C10EBA; Fri, 8 Nov 2019 14:21:20 +0100 (CET) Message-Id: <20191108131909.545730862@infradead.org> User-Agent: quilt/0.65 Date: Fri, 08 Nov 2019 14:15:56 +0100 From: Peter Zijlstra To: mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, juri.lelli@redhat.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de Cc: linux-kernel@vger.kernel.org, qperret@google.com, valentin.schneider@arm.com, qais.yousef@arm.com, ktkhai@virtuozzo.com, peterz@infradead.org Subject: [PATCH 3/7] sched: Make pick_next_task_idle() more consistent References: <20191108131553.027892369@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Only pick_next_task_fair() needs the @prev and @rf argument; these are required to implement the cpu-cgroup optimization. None of the other pick_next_task() methods need this. Make pick_next_task_idle() more consistent. Signed-off-by: Peter Zijlstra (Intel) --- kernel/sched/core.c | 6 ++++-- kernel/sched/idle.c | 3 +-- 2 files changed, 5 insertions(+), 4 deletions(-) --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -3922,8 +3922,10 @@ pick_next_task(struct rq *rq, struct tas goto restart; /* Assumes fair_sched_class->next == idle_sched_class */ - if (unlikely(!p)) - p = idle_sched_class.pick_next_task(rq, prev, rf); + if (unlikely(!p)) { + put_prev_task(rq, prev); + p = idle_sched_class.pick_next_task(rq, NULL, NULL); + } return p; } --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -390,8 +390,7 @@ pick_next_task_idle(struct rq *rq, struc { struct task_struct *next = rq->idle; - if (prev) - put_prev_task(rq, prev); + WARN_ON_ONCE(prev || rf); set_next_task_idle(rq, next);