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 08BD1C00140 for ; Mon, 15 Aug 2022 09:39:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242037AbiHOJjm (ORCPT ); Mon, 15 Aug 2022 05:39:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230153AbiHOJjj (ORCPT ); Mon, 15 Aug 2022 05:39:39 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 538F71EC61; Mon, 15 Aug 2022 02:39:38 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 0EFDD34AAE; Mon, 15 Aug 2022 09:39:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1660556377; h=from:from:reply-to: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=xLRt920Q9NTts46M0mpTJHEHc61MGrl7arvYDWKeJLY=; b=E9YwOiQ68gGhWyMiRiOYeVdDaQUKtIKU4zieATyAoF5818GH7zRobg+wLoG3UwPtQKb233 Roaao9shepnktb6xBF9IfdPMSvpitaha+8BA5ugV3cQ6r89TiNLeMq9Chvtl8BB3hKc02/ qpcsakl9FCZQX72Lr9LuVDej/1rrTUc= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id BADFB13A93; Mon, 15 Aug 2022 09:39:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 6U+RLFgU+mIvXwAAMHmgww (envelope-from ); Mon, 15 Aug 2022 09:39:36 +0000 Date: Mon, 15 Aug 2022 11:39:35 +0200 From: Michal =?iso-8859-1?Q?Koutn=FD?= To: Xuewen Yan Cc: Mukesh Ojha , Tejun Heo , Imran Khan , lizefan.x@bytedance.com, hannes@cmpxchg.org, tglx@linutronix.de, steven.price@arm.com, peterz@infradead.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Zhao Gongyi , Zhang Qiao Subject: Re: Query regarding deadlock involving cgroup_threadgroup_rwsem and cpu_hotplug_lock Message-ID: <20220815093934.GA29323@blackbody.suse.cz> References: <8245b710-8acb-d8e6-7045-99a5f71dad4e@oracle.com> <26d0e4cc-be0e-2c12-6174-dfbb1edb1ed6@oracle.com> <224b19f3-912d-b858-7af4-185b8e55bc66@quicinc.com> <20220815090556.GB27407@blackbody.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Aug 15, 2022 at 05:25:52PM +0800, Xuewen Yan wrote: > Your means is that the problem should be fixed by [1]+[2]'s revert ? I understood that was already the combination you had tested. You write in [T] that [1] alone causes (another) deadlock and therefore the revert of [2] was suggested. > I just tested the case which reverted the [2]. Need I test with [1] and [2]? It'd be better (unless you haven't already :-), my reasoning is for the [1]+[2] combo. Thanks, Michal [T] https://lore.kernel.org/r/CAB8ipk_gCLtvEahsp2DvPJf4NxRsM8WCYmmH=yTd7zQE+81_Yg@mail.gmail.com/ From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michal =?iso-8859-1?Q?Koutn=FD?= Subject: Re: Query regarding deadlock involving cgroup_threadgroup_rwsem and cpu_hotplug_lock Date: Mon, 15 Aug 2022 11:39:35 +0200 Message-ID: <20220815093934.GA29323@blackbody.suse.cz> References: <8245b710-8acb-d8e6-7045-99a5f71dad4e@oracle.com> <26d0e4cc-be0e-2c12-6174-dfbb1edb1ed6@oracle.com> <224b19f3-912d-b858-7af4-185b8e55bc66@quicinc.com> <20220815090556.GB27407@blackbody.suse.cz> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1660556377; h=from:from:reply-to: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=xLRt920Q9NTts46M0mpTJHEHc61MGrl7arvYDWKeJLY=; b=E9YwOiQ68gGhWyMiRiOYeVdDaQUKtIKU4zieATyAoF5818GH7zRobg+wLoG3UwPtQKb233 Roaao9shepnktb6xBF9IfdPMSvpitaha+8BA5ugV3cQ6r89TiNLeMq9Chvtl8BB3hKc02/ qpcsakl9FCZQX72Lr9LuVDej/1rrTUc= Content-Disposition: inline In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Xuewen Yan Cc: Mukesh Ojha , Tejun Heo , Imran Khan , lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, steven.price-5wv7dgnIgG8@public.gmane.org, peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Zhao Gongyi , Zhang Qiao On Mon, Aug 15, 2022 at 05:25:52PM +0800, Xuewen Yan wrote: > Your means is that the problem should be fixed by [1]+[2]'s revert ? I understood that was already the combination you had tested. You write in [T] that [1] alone causes (another) deadlock and therefore the revert of [2] was suggested. > I just tested the case which reverted the [2]. Need I test with [1] and [2]? It'd be better (unless you haven't already :-), my reasoning is for the [1]+[2] combo. Thanks, Michal [T] https://lore.kernel.org/r/CAB8ipk_gCLtvEahsp2DvPJf4NxRsM8WCYmmH=yTd7zQE+81_Yg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org/