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=-2.5 required=3.0 tests=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 69D7BC33CB1 for ; Fri, 17 Jan 2020 08:59:36 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 358E42082F for ; Fri, 17 Jan 2020 08:59:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 358E42082F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id CC0486B0333; Fri, 17 Jan 2020 03:59:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id C6F7D6B0334; Fri, 17 Jan 2020 03:59:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BADAC6B0335; Fri, 17 Jan 2020 03:59:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0063.hostedemail.com [216.40.44.63]) by kanga.kvack.org (Postfix) with ESMTP id A69CB6B0333 for ; Fri, 17 Jan 2020 03:59:35 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 67F78824805A for ; Fri, 17 Jan 2020 08:59:35 +0000 (UTC) X-FDA: 76386527910.10.blood01_53afddb73460f X-HE-Tag: blood01_53afddb73460f X-Filterd-Recvd-Size: 3129 Received: from mail-wr1-f67.google.com (mail-wr1-f67.google.com [209.85.221.67]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Fri, 17 Jan 2020 08:59:34 +0000 (UTC) Received: by mail-wr1-f67.google.com with SMTP id w15so21901788wru.4 for ; Fri, 17 Jan 2020 00:59:34 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=bU5V3HcfnedIuSE41RRJUJPnV/DJF/R8QkDrgRzYna0=; b=daf3efZHoYRVQY8hN5wfS+jIo3Cz30nO8Oj4xS1sq3RNl8v++Mgc3dEtuwqbB9x0nG 8dKiarO1bl+ipawTPrMrOmNLJuOkYobqDX+34eggiz0NgYue2JbDfYslqnX/eQxxhIfS Gs0Y4+M+B8ZWiXTKpxbd6uDYliYvZFq5giSxqSdo8R8L1G+X0lvIqM4jeIjDgD9Pqvve KsRwA8u33st376pgKWWD2MmsBqQo8yyzqLBQ5nxv5ClqCZFTnrw3z/bPPHIi6aeK7xMs 5M9aHhJ0Ty0BGeb1je5JTNR+ke8fgRkMbW+9CEP0Vm3W71a1Io5Bi2hXEZbGjQSB6e+k LniA== X-Gm-Message-State: APjAAAUGuAHfSD4SGhevre8i9VjRa+NffTCPTNG1FtR0yvX4Oii+swlt +CCnBfKG3bymecLvxxKv1yI= X-Google-Smtp-Source: APXvYqxtNWnpac+vRyvGriuN29/Et83dmU7tb+FO6rKdkdkIBjo+W46IOMGqukuyLbQGv7HpUwxI5Q== X-Received: by 2002:adf:f6c1:: with SMTP id y1mr1868575wrp.17.1579251573800; Fri, 17 Jan 2020 00:59:33 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id r62sm9737457wma.32.2020.01.17.00.59.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 00:59:33 -0800 (PST) Date: Fri, 17 Jan 2020 09:59:32 +0100 From: Michal Hocko To: David Hildenbrand Cc: Qian Cai , akpm@linux-foundation.org, sergey.senozhatsky.work@gmail.com, pmladek@suse.com, rostedt@goodmis.org, peterz@infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next v4] mm/hotplug: silence a lockdep splat with printk() Message-ID: <20200117085932.GK19428@dhcp22.suse.cz> References: <20200117022111.18807-1-cai@lca.pw> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) X-Bogosity: Ham, tests=bogofilter, spamicity=0.004423, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri 17-01-20 09:51:05, David Hildenbrand wrote: > On 17.01.20 03:21, Qian Cai wrote: [...] > > Even though has_unmovable_pages doesn't hold any reference to the > > returned page this should be reasonably safe for the purpose of > > reporting the page (dump_page) because it cannot be hotremoved. The > > This is only true in the context of memory unplug, but not in the > context of is_mem_section_removable()-> is_pageblock_removable_nolock(). Well, the above should hold for that path as well AFAICS. If the page is unmovable then a racing hotplug cannot remove it, right? Or do you consider a temporary unmovability to be a problem? -- Michal Hocko SUSE Labs