From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758848AbcIMO77 (ORCPT ); Tue, 13 Sep 2016 10:59:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57740 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752710AbcIMO75 (ORCPT ); Tue, 13 Sep 2016 10:59:57 -0400 Date: Tue, 13 Sep 2016 16:59:07 +0200 From: Oleg Nesterov To: Michal Hocko Cc: Dave Hansen , Xiao Guangrong , pbonzini@redhat.com, akpm@linux-foundation.org, dan.j.williams@intel.com, gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, stefanha@redhat.com, yuhuang@redhat.com, linux-mm@kvack.org, ross.zwisler@linux.intel.com Subject: Re: [PATCH v2] mm, proc: Fix region lost in /proc/self/smaps Message-ID: <20160913145906.GA28037@redhat.com> References: <1473649964-20191-1-git-send-email-guangrong.xiao@linux.intel.com> <20160912125447.GM14524@dhcp22.suse.cz> <57D6C332.4000409@intel.com> <20160912191035.GD14997@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160912191035.GD14997@dhcp22.suse.cz> User-Agent: Mutt/1.5.18 (2008-05-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 13 Sep 2016 14:59:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/12, Michal Hocko wrote: > > Considering how this all can be tricky and how partial reads can be > confusing and even misleading I am really wondering whether we > should simply document that only full reads will provide a sensible > results. I agree. I don't even understand why this was considered as a bug. Obviously, m_stop() which drops mmap_sep should not be called, or all the threads should be stopped, if you want to trust the result. Although all I can recall about this code is that it needs more cleanups. Oleg.