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 D2E84C433F5 for ; Tue, 30 Nov 2021 16:36:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244035AbhK3Qjq (ORCPT ); Tue, 30 Nov 2021 11:39:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238032AbhK3Qjp (ORCPT ); Tue, 30 Nov 2021 11:39:45 -0500 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7433DC061574 for ; Tue, 30 Nov 2021 08:36:26 -0800 (PST) Received: by mail-pf1-x42f.google.com with SMTP id r130so21237076pfc.1 for ; Tue, 30 Nov 2021 08:36:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=G9UcRoG6n7uSI6RSS4bAaNF3e1CzNs1fxTdoBdfl5jM=; b=qZzQYJspZBn9YHGzADbzUQDDgasoS0mJZE6iz43pBaZOB9DrtPqAZfVeKmjEvpnQMh WIstXIKb8Pvdomnzw0bE738NbVYon3tkYh17Oj/dGEQhAbz1HkTqduNSvKfi8+xMHbyU lCf3rrxazetPwRTvBBHwT4jTJqZZufec9V2wjeq5iZYAKssY5VwOBTjPLKQw/kkBPQzw t2/HIQJum/cCNW6sQJsAH1SDYlki1m8CO1KqWVFuEUZnqKjNI7tHbowweJN1XOnP0pVL Y49cNbPmXjppJQhi8Wbo75i57YAeZygk4jp6LjTTMnDU19/y4yqrKSsku0/PhXUnpToL nZKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=G9UcRoG6n7uSI6RSS4bAaNF3e1CzNs1fxTdoBdfl5jM=; b=qBoqQh7HpsvEXdDpnOoYe8ff2O3Za9u7SVyXLSijVEt4elYDbTcNziooDBQY8c2Nqh e648Ch4mzCMXx2J3FX4LZmbe9Ujkf3FQAYkAix7BuiUbKug4F2uLBNAwO/j4mhIwZehd SzcEXeDWQ9SV9KhkldCMTseLJR47c1fyCrAy/x/q2UaxQEYRyhuCcBKrHAgDn58UUJh5 qEVw8UuU0X2vU1QMJ0iyNsto4QcuxDGV+yv3H9EpQEg9yFI4pCRMPqYl5Mm9i4YFvauK sYEcHW/Qsd4Dni4oRYOxUnygHa5BOLsLd3fjEoO9qzm2Oi7bjTrpsJn1Cj8XMIOgFdf7 wJ6w== X-Gm-Message-State: AOAM532OS8nk3XhdkudEV5kU/WhUUDW7P3uzWOg9OHb5IbDwIy5jGYO8 klIKY/uLDob2HmMIlcDZoycsvUdmsGiw/g== X-Google-Smtp-Source: ABdhPJxiowYGgzDK3NHQz7bpm7p97sY1CByZVkt+RsJ2uGDGZ1cE0012erL4Fct6P5/KKPMu/QiWvg== X-Received: by 2002:a62:18d2:0:b0:4a2:b2d0:c39f with SMTP id 201-20020a6218d2000000b004a2b2d0c39fmr273009pfy.69.1638290185838; Tue, 30 Nov 2021 08:36:25 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-e24f-43ff-fee6-449f.res6.spectrum.com. [2603:800c:1a02:1bae:e24f:43ff:fee6:449f]) by smtp.gmail.com with ESMTPSA id a18sm20378723pfn.185.2021.11.30.08.36.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 08:36:25 -0800 (PST) Sender: Tejun Heo Date: Tue, 30 Nov 2021 06:36:23 -1000 From: Tejun Heo To: Frederic Weisbecker Cc: Lai Jiangshan , LKML , "Paul E . McKenney" Subject: Re: [RFC PATCH 0/2] workqueue: Fix hotplug races Message-ID: References: <20211130000612.591368-1-frederic@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211130000612.591368-1-frederic@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 30, 2021 at 01:06:10AM +0100, Frederic Weisbecker wrote: > While triggering rcutorture splats, I couldn't trace down to the exact > cause due to the issue being tracing-unfriendly. But looking at the code, > those two potential races look like plausible causes and also after > these two patches, I couldn't reproduce the rcutorture issues again (yet...). > > Frederic Weisbecker (2): > workqueue: Fix unbind_workers() VS wq_worker_running() race > workqueue: Fix unbind_workers() VS wq_worker_sleeping() race Both patches look good to me. Lai, thanks for finding the offending commits. Frederic, can you please repost them w/ scheduler folks and tglx cc'd? Thanks. -- tejun