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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 6FEF2C7618B for ; Fri, 26 Jul 2019 08:37:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4C841229F3 for ; Fri, 26 Jul 2019 08:37:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726640AbfGZIhd (ORCPT ); Fri, 26 Jul 2019 04:37:33 -0400 Received: from foss.arm.com ([217.140.110.172]:39620 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725842AbfGZIhc (ORCPT ); Fri, 26 Jul 2019 04:37:32 -0400 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 2EF41344; Fri, 26 Jul 2019 01:37:32 -0700 (PDT) Received: from [10.1.194.37] (e113632-lin.cambridge.arm.com [10.1.194.37]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2774F3F71A; Fri, 26 Jul 2019 01:37:31 -0700 (PDT) Subject: Re: [PATCH 4/5] sched/deadline: Cleanup on_dl_rq() handling To: Dietmar Eggemann , Peter Zijlstra , Ingo Molnar , Juri Lelli Cc: Luca Abeni , Daniel Bristot de Oliveira , Qais Yousef , linux-kernel@vger.kernel.org References: <20190726082756.5525-1-dietmar.eggemann@arm.com> <20190726082756.5525-5-dietmar.eggemann@arm.com> From: Valentin Schneider Message-ID: <0f460dba-4677-00de-59a2-5cd31ffe6e4b@arm.com> Date: Fri, 26 Jul 2019 09:37:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190726082756.5525-5-dietmar.eggemann@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 26/07/2019 09:27, Dietmar Eggemann wrote: > Remove BUG_ON() in __enqueue_dl_entity() since there is already one in > enqueue_dl_entity(). > > Move the check that the dl_se is not on the dl_rq from > __dequeue_dl_entity() to dequeue_dl_entity() to align with the enqueue > side and use the on_dl_rq() helper function. > > Signed-off-by: Dietmar Eggemann > --- > kernel/sched/deadline.c | 8 +++----- > 1 file changed, 3 insertions(+), 5 deletions(-) > > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c > index 1fa005f79307..a9cb52ceb761 100644 > --- a/kernel/sched/deadline.c > +++ b/kernel/sched/deadline.c > @@ -1407,8 +1407,6 @@ static void __enqueue_dl_entity(struct sched_dl_entity *dl_se) > struct sched_dl_entity *entry; > int leftmost = 1; > > - BUG_ON(!RB_EMPTY_NODE(&dl_se->rb_node)); > - > while (*link) { > parent = *link; > entry = rb_entry(parent, struct sched_dl_entity, rb_node); > @@ -1430,9 +1428,6 @@ static void __dequeue_dl_entity(struct sched_dl_entity *dl_se) > { > struct dl_rq *dl_rq = dl_rq_of_se(dl_se); > > - if (RB_EMPTY_NODE(&dl_se->rb_node)) > - return; > - Any idea why a similar error leads to a BUG_ON() in the enqueue path but only a silent return on the dequeue path? I would expect the handling to be almost identical.