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 5D056C00319 for ; Thu, 21 Feb 2019 16:07:12 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 240DF2084D for ; Thu, 21 Feb 2019 16:07:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 240DF2084D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id ADF588E0090; Thu, 21 Feb 2019 11:07:11 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A8F018E0002; Thu, 21 Feb 2019 11:07:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9565A8E0090; Thu, 21 Feb 2019 11:07:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by kanga.kvack.org (Postfix) with ESMTP id 6C4ED8E0002 for ; Thu, 21 Feb 2019 11:07:11 -0500 (EST) Received: by mail-qt1-f198.google.com with SMTP id k37so27046616qtb.20 for ; Thu, 21 Feb 2019 08:07:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=+lEt++79LSLnEqubkMvDdNhACmy8isPOksvi2/UaRhA=; b=SCwFAEZxTZEGN8BMsynH01MqsWqceXq0GFYC8KD4kfpB8vmwRgC+rBHxHBOYM1D7+Z lysJooX1UAGY8rtb05SqbNk0nKofXYY5vCHrv5w2l1+QvP/As7owRR4smSKPiXLlaEDi s02NFng8B2oT3+KQcGHAe+p0UnBf/ARHFSp28cQMASxbpSIxQ1NxKSGH5bDVRydRGUSB bmDsHbfzk5eYbs12db1ZxfMDHjrymtubeOurgQDYXtfmfqA/QzesEn19yXhFywpNMd6F OkYkAnCqOdgI2XwQB5jCXoxg+HTVP5DVQnZ/xVWa7DXMewOFEwK4s+/CK+HD1+PqiMyO oBpA== X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of jglisse@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jglisse@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com X-Gm-Message-State: AHQUAuY6oPAoshunwAl2U79xoYHoWKERyyf9y4Vcdj1U8VsYpRBrq9y6 f0skpgNnLnd7Xh2QZHBMc9FiF5619jHP6iOhJjzZBAyNNnT8O0NU0imcEY5ACNBZdQokfGN86VN Y4VOwQkCM8KPAZw83FxUd05hQDMK/wyhR0MOOHFw0Y30EDxE3smR6dH+OBjI1gC8zfQ== X-Received: by 2002:aed:314b:: with SMTP id 69mr438072qtg.247.1550765231117; Thu, 21 Feb 2019 08:07:11 -0800 (PST) X-Google-Smtp-Source: AHgI3IYbs5nna6i+xvaALRCHShBnbxHKL7EIYcjTayiZLtmuU05wPWFgRcU4u5qsLR4gXAd3fHAH X-Received: by 2002:aed:314b:: with SMTP id 69mr438021qtg.247.1550765230402; Thu, 21 Feb 2019 08:07:10 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1550765230; cv=none; d=google.com; s=arc-20160816; b=zwOpacHZENzwOvb8AXYKe+G5BB7KlAIyMk8dZBHZNeju9ypr2vfSyCIkjI+7Fi6Gve VJM/W6CjKi4fS+Xlbm5TOTLSd71qtxj0fjsbHES2ejFG9ZCk3q6Qxgf8Bpeez88bfO9B laeEDxLw/PHCVMB1I+taUp0CAb1UfuhAcsiCIosgzeSoywjcb6nkrdf5ADLxZjGBE0yM 7upyp8lwA22HmoQV8bwCHP8mwhI8IUhAB4vp7VsK8wj48WgmX4KmPPglHvs5vfXx2ACc YmiT6VyFpEHSUL0WB2Gd+hIpjD/EKQo1Slo3bBA9Gqhjmhn9jQGicHWgGe8KfNI4yECf mJaQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=+lEt++79LSLnEqubkMvDdNhACmy8isPOksvi2/UaRhA=; b=CC8y1Elqd0Yz0bacl5QrkElD0OZYqvfUKt68RZtAdsvEyoEPQNPlNPbtM/nalfNQwW iRepIoz7AfUj9PFFX50G+ZZwsIKft+yAQQ5rOvdne1WO9QarPrRAI/fYuqBOugC7zdga H+RhNChyv4ElLMdtQ2BOlvrHClCt5ujMctcfTW2oQ/6epkpYpJuY90QJh194phg5UW4Z 9BFpjYLUeIbxBGa+Q0osQtYIX6YU++QIxDiNoWyU+az7mHw2ngzbK9qCddYopakC3J7G jlLGkWQgDeiLnmyhwA2dkyw3dPqQUouEt88ToiFrorRCRF0fCaxRI7nOIqPImvWLPLKj G2BQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of jglisse@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jglisse@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id g11si869873qtc.86.2019.02.21.08.07.10 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Feb 2019 08:07:10 -0800 (PST) Received-SPF: pass (google.com: domain of jglisse@redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jglisse@redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=jglisse@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5B3D537F46; Thu, 21 Feb 2019 16:07:09 +0000 (UTC) Received: from redhat.com (unknown [10.20.6.236]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DBE9A1001DD8; Thu, 21 Feb 2019 16:06:57 +0000 (UTC) Date: Thu, 21 Feb 2019 11:06:55 -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: <20190221160612.GE2813@redhat.com> References: <20190212025632.28946-1-peterx@redhat.com> <20190212025632.28946-6-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190212025632.28946-6-peterx@redhat.com> User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 21 Feb 2019 16:07:09 +0000 (UTC) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 > --- > mm/gup.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/mm/gup.c b/mm/gup.c > index fa75a03204c1..ba387aec0d80 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -528,7 +528,10 @@ static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma, > if (*flags & FOLL_NOWAIT) > 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; > } > > @@ -943,17 +946,23 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, > /* VM_FAULT_RETRY triggered, so seek to the faulting offset */ > pages += ret; > start += ret << PAGE_SHIFT; > + lock_dropped = true; > > +retry: > /* > * Repeat on the address that fired VM_FAULT_RETRY > - * without FAULT_FLAG_ALLOW_RETRY but with > + * with both FAULT_FLAG_ALLOW_RETRY and > * FAULT_FLAG_TRIED. > */ > *locked = 1; > - lock_dropped = true; > down_read(&mm->mmap_sem); > ret = __get_user_pages(tsk, mm, start, 1, flags | FOLL_TRIED, > - pages, NULL, NULL); > + pages, NULL, locked); > + if (!*locked) { > + /* Continue to retry until we succeeded */ > + BUG_ON(ret != 0); > + goto retry; > + } > if (ret != 1) { > BUG_ON(ret > 1); > if (!pages_done) > -- > 2.17.1 >