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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 A1E77C4360C for ; Tue, 8 Oct 2019 13:48:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 754A6217D7 for ; Tue, 8 Oct 2019 13:48:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570542515; bh=VKc7Xxn5RL2X3cXGk70B3QLiIVOG5siFsmbVAIQfhbA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=mwbwfXxqCdEsDIvrn3tQH1dfgZkjArnBX7z56beYgjsrvhSPGqQ1qeDbiE2TsamG6 P97DCqYeCizV5Bn2i3iiks5Sd5YovlHpkleFUB8oLrR3LWJQqV34YfjZSTsyyET+Ia MIiHsMbTxD9oc9bmXy5EXNtxrYhcQQBH165Bncuc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725939AbfJHNse (ORCPT ); Tue, 8 Oct 2019 09:48:34 -0400 Received: from mx2.suse.de ([195.135.220.15]:45350 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725834AbfJHNse (ORCPT ); Tue, 8 Oct 2019 09:48:34 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 13FFBB1AC; Tue, 8 Oct 2019 13:48:32 +0000 (UTC) Date: Tue, 8 Oct 2019 15:48:31 +0200 From: Michal Hocko To: Petr Mladek Cc: Qian Cai , Steven Rostedt , sergey.senozhatsky.work@gmail.com, peterz@infradead.org, linux-mm@kvack.org, john.ogness@linutronix.de, akpm@linux-foundation.org, david@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm/page_isolation: fix a deadlock with printk() Message-ID: <20191008134831.GL6681@dhcp22.suse.cz> References: <1570228005-24979-1-git-send-email-cai@lca.pw> <20191007143002.l37bt2lzqtnqjqxu@pathway.suse.cz> <1570460350.5576.290.camel@lca.pw> <20191007151237.GP2381@dhcp22.suse.cz> <1570462407.5576.292.camel@lca.pw> <20191008081510.ptwmb7zflqiup5py@pathway.suse.cz> <20191008091349.6195830d@gandalf.local.home> <1570541032.5576.297.camel@lca.pw> <20191008134256.5ti6rjkvadn5b5q4@pathway.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191008134256.5ti6rjkvadn5b5q4@pathway.suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 08-10-19 15:42:56, Petr Mladek wrote: [...] > I am not -mm maintainer so I could not guarantee that a patch > using printk_deferred() will get accepted. But it will have much > bigger chance than the original patch. I am not going to ack any such patch until it is clear what is the actual problem. The disucssion in this thread boils down to point to lockdep splats which are most likely false possitives and there is no clear evidence that the is any actual deadlock as those would be clearly identifiable if the zone->lock or any other spinlock spinlock were participating. -- Michal Hocko SUSE Labs