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_PASS,USER_AGENT_MUTT autolearn=ham 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 03798C282C2 for ; Wed, 13 Feb 2019 16:18:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA84D21902 for ; Wed, 13 Feb 2019 16:18:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550074717; bh=+dsVqmrHA7YqMuFtOO9liuuXg7WvYJ/pQRPw864c2mI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ufOPaeVthibSIJxA6dX7XnzXGA7CP+SzoAeoBbmbRabkMJC509xP3LN6+LPWBgKsl rckqG+mMZd5K/LS8gDAbbc4NLUuv3eKf/7urJFRQaIX3xnJuDJFTDABIznIHxWytjR adz42nkNQDHbGqruxE4R2KoUhnwx/gtTFADGnKjk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392628AbfBMQSg (ORCPT ); Wed, 13 Feb 2019 11:18:36 -0500 Received: from mx2.suse.de ([195.135.220.15]:49098 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730572AbfBMQSg (ORCPT ); Wed, 13 Feb 2019 11:18:36 -0500 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 85ED4AD74; Wed, 13 Feb 2019 16:18:34 +0000 (UTC) Date: Wed, 13 Feb 2019 17:18:32 +0100 From: Michal Hocko To: Dave Hansen Cc: linux-mm@kvack.org, Pingfan Liu , Peter Zijlstra , x86@kernel.org, Benjamin Herrenschmidt , Michael Ellerman , Tony Luck , linuxppc-dev@lists.ozlabs.org, linux-ia64@vger.kernel.org, LKML , Ingo Molnar Subject: Re: [PATCH v3 2/2] mm: be more verbose about zonelist initialization Message-ID: <20190213161832.GT4525@dhcp22.suse.cz> References: <20190212095343.23315-3-mhocko@kernel.org> <20190213094315.3504-1-mhocko@kernel.org> <1433a7e9-87b2-7e8d-a87d-dcffe486635c@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1433a7e9-87b2-7e8d-a87d-dcffe486635c@intel.com> 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 Wed 13-02-19 08:14:50, Dave Hansen wrote: > On 2/13/19 1:43 AM, Michal Hocko wrote: > > > > We have seen several bugs where zonelists have not been initialized > > properly and it is not really straightforward to track those bugs down. > > One way to help a bit at least is to dump zonelists of each node when > > they are (re)initialized. > > Were you thinking of boot-time bugs and crashes, or just stuff going > wonky after boot? Mostly boot time. I haven't seen hotplug related bugs in this direction. All the issues I have seen so far is that we forget a node altogether and it ends up with no zonelists at all. But who knows maybe we have some hidden bugs where zonelists is initialized only partially for some reason and there is no real way to find out. > We don't have the zonelists dumped in /proc anywhere, do we? Would that > help? I would prefer to not export such an implementation detail into proc -- Michal Hocko SUSE Labs