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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=unavailable 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 845A2C4338F for ; Mon, 26 Jul 2021 13:41:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B75360243 for ; Mon, 26 Jul 2021 13:41:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234180AbhGZNAt (ORCPT ); Mon, 26 Jul 2021 09:00:49 -0400 Received: from foss.arm.com ([217.140.110.172]:52018 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233719AbhGZM7G (ORCPT ); Mon, 26 Jul 2021 08:59:06 -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 8CE6B139F; Mon, 26 Jul 2021 06:39:34 -0700 (PDT) Received: from e113632-lin (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A3CF33F70D; Mon, 26 Jul 2021 06:39:32 -0700 (PDT) From: Valentin Schneider To: Pavel Machek , Steven Rostedt Cc: linux-kernel@vger.kernel.org, linux-rt-users , Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Daniel Wagner , Tom Zanussi , "Srivatsa S. Bhat" , stable@kernel.org, "Peter Zijlstra \(Intel\)" , Ingo Molnar , Paul Gortmaker Subject: Re: [PATCH RT 5/8] sched: Fix affine_move_task() self-concurrency In-Reply-To: <20210725050349.GA983@bug> References: <20210709215953.122804544@goodmis.org> <20210709220018.003428207@goodmis.org> <20210725050349.GA983@bug> Date: Mon, 26 Jul 2021 14:39:27 +0100 Message-ID: <87zgu9kxdc.mognet@arm.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/07/21 07:03, Pavel Machek wrote: > Hi! > >> 5.10.47-rt46-rc1 stable review patch. >> If anyone has any objections, please let me know. >> >> Add set_affinity_pending::stop_pending, to indicate if a stopper is in >> progress. >> diff --git a/kernel/sched/core.c b/kernel/sched/core.c >> index 9cbe12d8c5bd..20588a59300d 100644 >> --- a/kernel/sched/core.c >> +++ b/kernel/sched/core.c >> @@ -1900,6 +1900,7 @@ struct migration_arg { >> >> struct set_affinity_pending { >> refcount_t refs; >> + unsigned int stop_pending; >> struct completion done; >> struct cpu_stop_work stop_work; >> struct migration_arg arg; > > For better readability, this should be bool, AFAICT. > It's intentionally declared as an int. sizeof(_Bool) is Implementation Defined, so you can't sanely reason about struct layout. There's been quite a few threads about this already, a quick search on lore gave me: https://lore.kernel.org/lkml/20180411081502.GJ4082@hirez.programming.kicks-ass.net/