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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77912CD68EC for ; Tue, 10 Oct 2023 05:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346692AbjJJFfE (ORCPT ); Tue, 10 Oct 2023 01:35:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344471AbjJJFfD (ORCPT ); Tue, 10 Oct 2023 01:35:03 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ABFAA3 for ; Mon, 9 Oct 2023 22:34:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696916058; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=of3RE6QBF1Jz2L+QOoIOgtERkMPSFMmd7Q1awSev4MA=; b=YWOUAhMm4VfPf7Q/GI7UGr7an2X7buN8gw1QGM+n3YuxCjpm4E/Eq3KkIP5+IYcFJ7VNVU KglXb5b/YVK1VJp1Ieh3v9N5xBxWZ/38qVk50naCPLvlhJ7VVW0lXhlqReQWwPVm8ibzoD UJOEOOYHb9gOct34CiAENUYIsGdRzxw= Received: from mail-qv1-f71.google.com (mail-qv1-f71.google.com [209.85.219.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-335-EmDEowfzNHWpP9GcMGosNA-1; Tue, 10 Oct 2023 01:34:14 -0400 X-MC-Unique: EmDEowfzNHWpP9GcMGosNA-1 Received: by mail-qv1-f71.google.com with SMTP id 6a1803df08f44-66acad63d74so66661376d6.3 for ; Mon, 09 Oct 2023 22:34:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1696916054; x=1697520854; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=of3RE6QBF1Jz2L+QOoIOgtERkMPSFMmd7Q1awSev4MA=; b=GnHz+LCFfLNJgVvBM3KLYS09+0L1LqFhHf2Hi9hthZBiTUfuaYRbfT94id+gYE9NWy ptKC5JIfSb3aleYd1+7F17ZAl3mVtABFanfylSxSmJARlFq/rJHJvGKaOfh7hsTCa+r2 qpqjLW30sRJVFHMeOHaYJ5GKQLlWJ3pCQVgZHXJTKyi+0YbmknVdCG+DOIR+Gvy7X55k /2qODRU09rINDvHWLyC6zJ8MCUQVb53FjCq4pa57Hpnq4B+2FYuzOzQXFHJsPiExThkO uND7o3esf7jcB/d+/4LqRh//BVL7VqOrDCZh9a5/kTT0CLAQ5UyIHiF0PNW5mth9oKIQ jesg== X-Gm-Message-State: AOJu0YwxSEmCRmcxp1sa9vttN5uQ4ACtDdXdtRMcs9usOhGQtTvTt40G CjanQ97p4i9efyYHNBKWZBIcYhtjqU8YIYIZKj+6OtbyO+a+6MiQWJajTpU7xFSYSoJHTE7Ioo1 zLp1/xLWTkgC+KnuTAw== X-Received: by 2002:a05:6214:328b:b0:658:2857:ed6a with SMTP id mu11-20020a056214328b00b006582857ed6amr18640314qvb.43.1696916053786; Mon, 09 Oct 2023 22:34:13 -0700 (PDT) X-Google-Smtp-Source: AGHT+IE0WC8L+ycQI+fYRdUbPG5RVHhmq4l5+bGDvYcdBpkAQmLcoaJrY3uknAihXVyU3c9vmCUmxQ== X-Received: by 2002:a05:6214:328b:b0:658:2857:ed6a with SMTP id mu11-20020a056214328b00b006582857ed6amr18640303qvb.43.1696916053527; Mon, 09 Oct 2023 22:34:13 -0700 (PDT) Received: from localhost.localdomain ([151.29.94.163]) by smtp.gmail.com with ESMTPSA id j11-20020a0ce00b000000b0065d034d8f39sm4436584qvk.81.2023.10.09.22.34.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Oct 2023 22:34:13 -0700 (PDT) Date: Tue, 10 Oct 2023 07:34:08 +0200 From: Juri Lelli To: Waiman Long Cc: Tejun Heo , Zefan Li , Johannes Weiner , linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Peter Zijlstra , Ingo Molnar , Qais Yousef , Hao Luo , Dietmar Eggemann , Steven Rostedt , Xia Fukun Subject: Re: [PATCH] cgroup/cpuset: Change nr_deadline_tasks to an atomic_t value Message-ID: References: <20231009191515.3262292-1-longman@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231009191515.3262292-1-longman@redhat.com> Precedence: bulk List-ID: X-Mailing-List: cgroups@vger.kernel.org Hi, On 09/10/23 15:15, Waiman Long wrote: > The nr_deadline_tasks field in cpuset structure was introduced by > commit 6c24849f5515 ("sched/cpuset: Keep track of SCHED_DEADLINE task > in cpusets"). Unlike nr_migrate_dl_tasks which is only modified under > cpuset_mutex, nr_deadline_tasks can be updated in various contexts > under different locks. As a result, data races may happen that cause > incorrect value to be stored in nr_deadline_tasks leading to incorrect Could you please make an example of such data races? Thanks! Juri