From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1205759-1523157141-2-16303425884625300934 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1523157141; b=YkPwdruo24KfQaXPeGag5eP7Fv3jhm4mWr1JcG2mO7oEg4xFcl KFmy+1S5T2r2nKluT2oNa6ucv5f2KGrLL5gknTQCy7caM/6IUlmvZc7/P4VS/JlV 9BAnjOqY/aAkPb866Ot8YXioxH3SH4Vkfep+8+J1p1Q8rM4imsKueU+p3uIGJvwY 4etdiMIClEcoRF6PPMc4Csab0zZo3LRg2hu2oGD/ufS3ViIRKZwdXZU6RvCazk+V mUPZkQkZFwP4B8fCToKBWHMSrtMYCpd87zKgz/Dkc6s69AeIkDlEekD1JEIm5zib 6ODiGNlE4gQiv0QH12W0VrTFUoWLlbnEQxkg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=fm2; t=1523157141; bh=ZmS9NEtAAfxV7cNULLSVPTKJI+A9fX 3O8OfPr9BghEE=; b=UXBLdIa+6jKcsZSPXxdLZxTMtBqTZ3o3e9A88z67MCUF+3 hhW/zPyBbgRn6pvqmfLkyhbmissxsOdCcIkgB71juV7C2CJQdjIyCtmXIlTAQwWV MMoKuZX8PBWZMjEnE+HwDNybOjfxsK3BefVnUUclS97gb2e+UiMw/m72mVkQwJL0 IyIkflxB7oYzgpyBcEr0eZW2rLwESE9lVLwov8tTqs6VH/zcoHpdmqW3tWN1Ouv2 qaIyIkL2FZCUccZXnLitw2S7NMexa1YQAEmsI1lOtUlM8rIdj5LkBXcUhCMMMRH7 rOPqv9aSdTEweXZsS+56yD1Pq6lKEt5AaM04an1g== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=fail (p=none,has-list-id=yes,d=none) header.from=redhat.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=redhat.com header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfMcsiaApiNsTpleH5LZQBidoBSnJNR2OIvCEkgA/MATPEkuAuPnhzUhzI3zlKhix+dporXxDUpCHXNK55lbw0AVq0et1QCcdKeXB4lb8sP/BuJsImumn QCGG7DcmqxwD1Ybdkhw+aGU4OsLRyXrbY6MOYzh1W+JR907/+RByB74pAS1h+vWP+Y4HOa+gbSU2aIMHg0J/dvMguj5PqtDZ3UWJ3TL27QLnIEDTbnzaE5Ar X-CM-Analysis: v=2.3 cv=JLoVTfCb c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=Kd1tUaAdevIA:10 a=20KFwNOVAAAA:8 a=lqAKIwt-UqUpJVJSZBIA:9 a=CjuIK1q_8ugA:10 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752463AbeDHDMS (ORCPT ); Sat, 7 Apr 2018 23:12:18 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:57784 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752460AbeDHDMS (ORCPT ); Sat, 7 Apr 2018 23:12:18 -0400 Date: Sun, 8 Apr 2018 06:12:13 +0300 From: "Michael S. Tsirkin" To: Linus Torvalds Cc: Linux Kernel Mailing List , "Kirill A . Shutemov" , Andrew Morton , Huang Ying , Jonathan Corbet , Peter Zijlstra , Thomas Gleixner , Thorsten Leemhuis , stable , linux-mm Subject: Re: [PATCH v2 1/3] mm/gup_benchmark: handle gup failures Message-ID: <20180408060935-mutt-send-email-mst@kernel.org> References: <1522962072-182137-1-git-send-email-mst@redhat.com> <1522962072-182137-3-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Sat, Apr 07, 2018 at 01:08:43PM -0700, Linus Torvalds wrote: > On Thu, Apr 5, 2018 at 2:03 PM, Michael S. Tsirkin wrote: > > > > nr = get_user_pages_fast(addr, nr, gup->flags & 1, pages + i); > > - i += nr; > > + if (nr > 0) > > + i += nr; > > Can we just make this robust while at it, and just make it > > if (nr <= 0) > break; > > instead? Then it doesn't care about zero vs negative error, and > wouldn't get stuck in an endless loop if it got zero. > > Linus I don't mind though it alredy breaks out on the next cycle: if (nr != gup->nr_pages_per_call) break; the only issue is i getting corrupted when nr < 0;