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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 BB090C43381 for ; Fri, 22 Feb 2019 15:13:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F7C920657 for ; Fri, 22 Feb 2019 15:13:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727122AbfBVPNb (ORCPT ); Fri, 22 Feb 2019 10:13:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2686 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725887AbfBVPNa (ORCPT ); Fri, 22 Feb 2019 10:13:30 -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 427E43097088; Fri, 22 Feb 2019 15:13:30 +0000 (UTC) Received: from redhat.com (ovpn-126-14.rdu2.redhat.com [10.10.126.14]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F20E4600CD; Fri, 22 Feb 2019 15:13:23 +0000 (UTC) Date: Fri, 22 Feb 2019 10:13:22 -0500 From: Jerome Glisse To: Peter Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, David Hildenbrand , Hugh Dickins , Maya Gokhale , Pavel Emelyanov , Johannes Weiner , Martin Cracauer , Shaohua Li , Marty McFadden , Andrea Arcangeli , Mike Kravetz , Denis Plotnikov , Mike Rapoport , Mel Gorman , "Kirill A . Shutemov" , "Dr . David Alan Gilbert" Subject: Re: [PATCH v2 05/26] mm: gup: allow VM_FAULT_RETRY for multiple times Message-ID: <20190222151321.GB7783@redhat.com> References: <20190212025632.28946-1-peterx@redhat.com> <20190212025632.28946-6-peterx@redhat.com> <20190221160612.GE2813@redhat.com> <20190222044105.GE8904@xz-x1> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190222044105.GE8904@xz-x1> User-Agent: Mutt/1.10.1 (2018-07-13) 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 [10.5.110.43]); Fri, 22 Feb 2019 15:13:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 22, 2019 at 12:41:05PM +0800, Peter Xu wrote: > On Thu, Feb 21, 2019 at 11:06:55AM -0500, Jerome Glisse wrote: > > On Tue, Feb 12, 2019 at 10:56:11AM +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 > > > > Reviewed-by: Jérôme Glisse > > Thanks for the r-b, Jerome! > > Though I plan to change this patch a bit because I just noticed that I > didn't touch up the hugetlbfs path for GUP. Though it was not needed > for now because hugetlbfs is not yet supported but I think maybe I'd > better do that as well in this same patch to make follow up works > easier on hugetlb, and the patch will be more self contained. The new > version will simply squash below change into current patch: > > diff --git a/mm/hugetlb.c b/mm/hugetlb.c > index e3c738bde72e..a8eace2d5296 100644 > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -4257,8 +4257,10 @@ long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma, > fault_flags |= FAULT_FLAG_ALLOW_RETRY | > FAULT_FLAG_RETRY_NOWAIT; > if (flags & FOLL_TRIED) { > - VM_WARN_ON_ONCE(fault_flags & > - FAULT_FLAG_ALLOW_RETRY); > + /* > + * Note: FAULT_FLAG_ALLOW_RETRY and > + * FAULT_FLAG_TRIED can co-exist > + */ > fault_flags |= FAULT_FLAG_TRIED; > } > ret = hugetlb_fault(mm, vma, vaddr, fault_flags); > > I'd say this change is straightforward (it's the same as the > faultin_page below but just for hugetlbfs). Please let me know if you > still want to offer the r-b with above change squashed (I'll be more > than glad to take it!), or I'll just wait for your review comment when > I post the next version. Looks good i should have thought of hugetlbfs. You can keep my r-b. Cheers, Jérôme