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=-0.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 DC389FA3728 for ; Thu, 17 Oct 2019 00:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AEF4A218DE for ; Thu, 17 Oct 2019 00:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571273404; bh=IYJzNb9unWNMZK55GWXexB0DpsKeOwmGxuFGk3dxhMA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=jhWewkUwY4TqHkd2o5za0EM8vYcSJ9glOvUuNx6MRq8eCvD8lx3g2Ch1SlLCE1n1d P49i2hTWG51hy1CVBRpWlPwprXJGhF5PmmBL/enriDJuZQNecAhAM+r/HI/Eg65oxE ZisYKL7muiIKMSXuKp502RPLn6UXvxc3nqw+fYyw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405384AbfJQAt5 (ORCPT ); Wed, 16 Oct 2019 20:49:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:37304 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403893AbfJQAt4 (ORCPT ); Wed, 16 Oct 2019 20:49:56 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CC56420872; Thu, 17 Oct 2019 00:49:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571273396; bh=IYJzNb9unWNMZK55GWXexB0DpsKeOwmGxuFGk3dxhMA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZF1baU1o3y5gSgLWTM6fEbQK9smKG/HjbhMqyqekJ0qvU5Nm6MbJeLUHCSeNh5w3J tg3gDIAsXqpfhuNrM0faCk4eASmCQYMgKcHSZJkC4YFi7z7U1XUCR6tXGkZFgICAao UECGGb/C/2pSDVkEp9eeIi9yxgwjVWUtPiI79YTw= Date: Wed, 16 Oct 2019 17:49:55 -0700 From: Andrew Morton To: zhong jiang Cc: John Hubbard , Vlastimil Babka , , , , , Ira Weiny , "Aneesh Kumar K.V" Subject: Re: [PATCH] mm: Unsigned 'nr_pages' always larger than zero Message-Id: <20191016174955.300d5fd4968537151d3ad43f@linux-foundation.org> In-Reply-To: <5DA6DDE0.6000804@huawei.com> References: <1567592763-25282-1-git-send-email-zhongjiang@huawei.com> <5505fa16-117e-8890-0f48-38555a61a036@suse.cz> <20190904114820.42d9c4daf445ded3d0da52ab@linux-foundation.org> <73c49a1b-4f42-c21d-ccd8-2b063cdf1293@nvidia.com> <5DA6DDE0.6000804@huawei.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Oct 2019 17:07:44 +0800 zhong jiang wrote: > >> --- a/mm/gup.c~a > >> +++ a/mm/gup.c > >> @@ -1450,6 +1450,7 @@ static long check_and_migrate_cma_pages( > >> bool drain_allow = true; > >> bool migrate_allow = true; > >> LIST_HEAD(cma_page_list); > >> + long ret; > >> check_again: > >> for (i = 0; i < nr_pages;) { > >> @@ -1511,17 +1512,18 @@ check_again: > >> * again migrating any new CMA pages which we failed to isolate > >> * earlier. > >> */ > >> - nr_pages = __get_user_pages_locked(tsk, mm, start, nr_pages, > >> + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, > >> pages, vmas, NULL, > >> gup_flags); > >> - if ((nr_pages > 0) && migrate_allow) { > >> + nr_pages = ret; > >> + if (ret > 0 && migrate_allow) { > >> drain_allow = true; > >> goto check_again; > >> } > >> } > >> - return nr_pages; > >> + return ret; > >> } > >> #else > >> static long check_and_migrate_cma_pages(struct task_struct *tsk, > >> > > > > +1 for this approach, please. > > > > > > thanks, > Hi, Andrew > > I didn't see the fix for the issue in the upstream. Your proposal should be > appiled to upstream. Could you appiled the patch or repost by me ? Forgotten about it ;) Please send a patch sometime?