From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753291AbdDJMi2 (ORCPT ); Mon, 10 Apr 2017 08:38:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53714 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103AbdDJMi1 (ORCPT ); Mon, 10 Apr 2017 08:38:27 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 8DE668046B Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=riel@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com 8DE668046B Message-ID: <1491827904.8850.178.camel@redhat.com> Subject: Re: [PATCH] mm, numa: Fix bad pmd by atomically check for pmd_trans_huge when marking page tables prot_numa From: Rik van Riel To: Mel Gorman , Andrew Morton Cc: Andrea Arcangeli , Michal Hocko , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 10 Apr 2017 08:38:24 -0400 In-Reply-To: <20170410094825.2yfo5zehn7pchg6a@techsingularity.net> References: <20170410094825.2yfo5zehn7pchg6a@techsingularity.net> Organization: Red Hat, Inc Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Mon, 10 Apr 2017 12:38:26 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2017-04-10 at 10:48 +0100, Mel Gorman wrote: > > While this could be fixed with heavy locking, it's only necessary to > make a copy of the PMD on the stack during change_pmd_range and avoid > races. A new helper is created for this as the check if quite subtle > and the > existing similar helpful is not suitable. This passed 154 hours of > testing > (usually triggers between 20 minutes and 24 hours) without detecting > bad > PMDs or corruption. A basic test of an autonuma-intensive workload > showed > no significant change in behaviour. > > Signed-off-by: Mel Gorman > Cc: stable@vger.kernel.org Acked-by: Rik van Riel