From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752888AbeDRJCX (ORCPT ); Wed, 18 Apr 2018 05:02:23 -0400 Received: from mail-lf0-f52.google.com ([209.85.215.52]:37968 "EHLO mail-lf0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751870AbeDRJCW (ORCPT ); Wed, 18 Apr 2018 05:02:22 -0400 X-Google-Smtp-Source: AIpwx48nmra4krN2Nvurf19mJ7curHJaX3wNxUpzmWyLf7JnmLj8xgrTa4Ml3G2NeMmF3+7yc5OhLQ== Date: Wed, 18 Apr 2018 12:02:17 +0300 From: Cyrill Gorcunov To: Michal Hocko Cc: Yang Shi , adobriyan@gmail.com, willy@infradead.org, mguzik@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [v4 PATCH] mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct Message-ID: <20180418090217.GG19578@uranus.lan> References: <1523730291-109696-1-git-send-email-yang.shi@linux.alibaba.com> <20180418080555.GR17484@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180418080555.GR17484@dhcp22.suse.cz> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 18, 2018 at 10:05:55AM +0200, Michal Hocko wrote: > > Yes, looks good to me. As mentioned in other emails prctl_set_mm_map > really deserves a comment explaining why we are doing the down_read > > What about something like the following? > " > arg_lock protects concurent updates but we still need mmap_sem for read > to exclude races with do_brk. > " > Acked-by: Michal Hocko Yes, thanks! Andrew, could you slightly update the changelog please?