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 87725ECAAA1 for ; Tue, 6 Sep 2022 18:30:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbiIFSar (ORCPT ); Tue, 6 Sep 2022 14:30:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229708AbiIFSao (ORCPT ); Tue, 6 Sep 2022 14:30:44 -0400 Received: from mail-pl1-x62b.google.com (mail-pl1-x62b.google.com [IPv6:2607:f8b0:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F0AC317E3C; Tue, 6 Sep 2022 11:30:43 -0700 (PDT) Received: by mail-pl1-x62b.google.com with SMTP id u22so12084348plq.12; Tue, 06 Sep 2022 11:30:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date; bh=XgR/VP7NAhWauMOsrwcgIw4hBbhzAc1gPVaPVW58FU4=; b=S0fGy3Amy4jLKzuOHjKtRyPXTXPwsHuseA5jDpGwgXLMWKnDw9zRiwSKKo7O5Q/hOS LouY1sFAeHQBoDjypEXbFeLyxrjIzIiq//XsVdH9HR8vYwJl9TsrdpKS3ETQdJR7SAcb LDXBubAEA2lklGik3H1FSYpdt7J2XoaJlUr7sH3ht/xkgT2hAlWId1cjanJn4WNCSYkD qwA+UwuSZoYf5J1TeqNALYVszB4PYXcjVbLXWs7E91eAKhvFPM2byJ8TUSIrdcFZOQ1R xZIXH+U3kSC5zEdIPoL3lCrE1nPLx2y4A1djzpPAPsIwaqBXqYM9BuRC7NvWENr09cCq bLhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date; bh=XgR/VP7NAhWauMOsrwcgIw4hBbhzAc1gPVaPVW58FU4=; b=Qg37A/4vlOclBnY5e2UvksUqx/syAieGjsQ5LAw1Pb8io12JwaeCoh2GVCqHIhBWDL hPtN2MkHdKfF2nwAgjEKhgFkc3yYRldp+RDJTIZ3TpyJ17xD8r/2j0HuEUiKC0ClMejT zmmp8mt2s+tmJvNfELll/ScZO9zCJGvPwkFGbJ8ZJgatoBTavNECGoaJJ7LcOeGhQ98+ owMxA/LddOORInEtwOxSCtimpRRj3qYKPYOUw5lmybrjk6l0L+9VLEY64MgcyqetDNEX sXAunKhd0YbKwSE/UkM4qmU5U2PIPiBBh7Iy0AUZRlu2r+JViNffBUNz4CDEhnufh6t1 2aag== X-Gm-Message-State: ACgBeo3nT9VcsQDzfBjajOyoVRMTEsHNDtnpS0ik5hrg2nhQPeGcZe6T XaDDlc1TzrVcagsk3utbxDPwY5Zfy7c= X-Google-Smtp-Source: AA6agR7xwQzeEteyz/qsiN1TMQKL/kt8HG+oZBtL6gOlaPJR0iFY+K5yJ6jN1awDrocqkyJ2OZtU3g== X-Received: by 2002:a17:903:41c2:b0:174:6cec:8d0d with SMTP id u2-20020a17090341c200b001746cec8d0dmr28511777ple.123.1662489043141; Tue, 06 Sep 2022 11:30:43 -0700 (PDT) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id n7-20020a170902d2c700b001709e3c755fsm2588998plc.230.2022.09.06.11.30.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Sep 2022 11:30:42 -0700 (PDT) Sender: Tejun Heo Date: Tue, 6 Sep 2022 08:30:41 -1000 From: Tejun Heo To: Jing-Ting Wu Cc: Mukesh Ojha , Peter Zijlstra , Valentin Schneider , wsd_upstream@mediatek.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Jonathan.JMChen@mediatek.com, "chris.redpath@arm.com" , Dietmar Eggemann , Vincent Donnefort , Ingo Molnar , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Christian Brauner , cgroups@vger.kernel.org, lixiong.liu@mediatek.com, wenju.xu@mediatek.com, Waiman Long Subject: Re: BUG: HANG_DETECT waiting for migration_cpu_stop() complete Message-ID: References: <88b2910181bda955ac46011b695c53f7da39ac47.camel@mediatek.com> <203d4614c1b2a498a240ace287156e9f401d5395.camel@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <203d4614c1b2a498a240ace287156e9f401d5395.camel@mediatek.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, (cc'ing Waiman in case he has a better idea) On Mon, Sep 05, 2022 at 04:22:29PM +0800, Jing-Ting Wu wrote: > https://lore.kernel.org/lkml/YvrWaml3F+x9Dk+T@slm.duckdns.org/ is for > fix cgroup_threadgroup_rwsem <-> cpus_read_lock() deadlock. > But this issue is cgroup_threadgroup_rwsem <-> cpuset_rwsem deadlock. If I'm understanding what you're writing correctly, this isn't a deadlock. The cpuset_hotplug_workfn simply isn't being woken up while holding cpuset_rwsem and others are just waiting for that lock to be released. Thanks. -- tejun