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 A6CCBC282C5 for ; Thu, 24 Jan 2019 15:34:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71960218AF for ; Thu, 24 Jan 2019 15:34:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728471AbfAXPeh (ORCPT ); Thu, 24 Jan 2019 10:34:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35136 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727649AbfAXPeh (ORCPT ); Thu, 24 Jan 2019 10:34:37 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 64EAC142BF1; Thu, 24 Jan 2019 15:34:36 +0000 (UTC) Received: from redhat.com (unknown [10.20.6.236]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E25A661370; Thu, 24 Jan 2019 15:34:33 +0000 (UTC) Date: Thu, 24 Jan 2019 10:34:32 -0500 From: Jerome Glisse To: Peter Xu 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: <20190124153431.GB5030@redhat.com> References: <20190121075722.7945-1-peterx@redhat.com> <20190121075722.7945-5-peterx@redhat.com> <20190121162455.GC3711@redhat.com> <20190124070503.GJ18231@xz-x1> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190124070503.GJ18231@xz-x1> User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 24 Jan 2019 15:34:37 +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 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. Cheers, Jérôme