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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 34660C282C3 for ; Fri, 25 Jan 2019 02:49:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F34D7218D2 for ; Fri, 25 Jan 2019 02:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728648AbfAYCtr (ORCPT ); Thu, 24 Jan 2019 21:49:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41340 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726107AbfAYCtr (ORCPT ); Thu, 24 Jan 2019 21:49:47 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2F9A9397F; Fri, 25 Jan 2019 02:49:46 +0000 (UTC) Received: from xz-x1 (ovpn-12-78.pek2.redhat.com [10.72.12.78]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 20BD84A4; Fri, 25 Jan 2019 02:49:38 +0000 (UTC) Date: Fri, 25 Jan 2019 10:49:36 +0800 From: Peter Xu To: Jerome Glisse Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins , Maya Gokhale , Johannes Weiner , Martin Cracauer , Denis Plotnikov , Shaohua Li , Andrea Arcangeli , Mike Kravetz , Marty McFadden , Mike Rapoport , Mel Gorman , "Kirill A . Shutemov" , "Dr . David Alan Gilbert" Subject: Re: [PATCH RFC 04/24] mm: gup: allow VM_FAULT_RETRY for multiple times Message-ID: <20190125024936.GO18231@xz-x1> References: <20190121075722.7945-1-peterx@redhat.com> <20190121075722.7945-5-peterx@redhat.com> <20190121162455.GC3711@redhat.com> <20190124070503.GJ18231@xz-x1> <20190124153431.GB5030@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190124153431.GB5030@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Fri, 25 Jan 2019 02:49:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 24, 2019 at 10:34:32AM -0500, Jerome Glisse wrote: > On Thu, Jan 24, 2019 at 03:05:03PM +0800, Peter Xu wrote: > > On Mon, Jan 21, 2019 at 11:24:55AM -0500, Jerome Glisse wrote: > > > On Mon, Jan 21, 2019 at 03:57:02PM +0800, Peter Xu wrote: > > > > This is the gup counterpart of the change that allows the VM_FAULT_RETRY > > > > to happen for more than once. > > > > > > > > Signed-off-by: Peter Xu > > > > > > So it would be nice to add a comment in the code and in the commit message > > > about possible fault starvation (mostly due to previous patch changes) as > > > if some one experience that and try to bisect it might overlook the commit. > > > > > > Otherwise: > > > > > > Reviewed-by: Jérôme Glisse > > > > Jerome, can I still keep this r-b if I'm going to fix the starvation > > issue you mentioned in previous patch about lock page? > > > > No please, i still want to review properly the oneline ie making sure > that it will not change any of the existing use of FAULT_FLAG_TRIED > I am finishing a bunch of patches myself so i am bit short on time right > now to take a deeper look but i will try to do that in next few days :) > > In anycase i will review again your next posting. Sure thing. Thank you Jerome! -- Peter Xu