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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=unavailable 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 1726DC282CE for ; Wed, 24 Apr 2019 23:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8742214AE for ; Wed, 24 Apr 2019 23:40:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728587AbfDXXk4 (ORCPT ); Wed, 24 Apr 2019 19:40:56 -0400 Received: from outbound-smtp09.blacknight.com ([46.22.139.14]:47450 "EHLO outbound-smtp09.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728535AbfDXXk4 (ORCPT ); Wed, 24 Apr 2019 19:40:56 -0400 Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp09.blacknight.com (Postfix) with ESMTPS id 751841C1DBF for ; Thu, 25 Apr 2019 00:40:54 +0100 (IST) Received: (qmail 21671 invoked from network); 24 Apr 2019 23:40:54 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[37.228.225.79]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 24 Apr 2019 23:40:54 -0000 Date: Thu, 25 Apr 2019 00:40:53 +0100 From: Mel Gorman To: Andrew Morton Cc: Andrey Ryabinin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm/page_alloc: fix never set ALLOC_NOFRAGMENT flag Message-ID: <20190424234052.GW18914@techsingularity.net> References: <20190423120806.3503-1-aryabinin@virtuozzo.com> <20190423120806.3503-2-aryabinin@virtuozzo.com> <20190423120143.f555f77df02a266ba2a7f1fc@linux-foundation.org> <20190424090403.GS18914@techsingularity.net> <20190424154624.f1084195c36684453a557718@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20190424154624.f1084195c36684453a557718@linux-foundation.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 24, 2019 at 03:46:24PM -0700, Andrew Morton wrote: > On Wed, 24 Apr 2019 10:04:03 +0100 Mel Gorman wrote: > > > On Tue, Apr 23, 2019 at 12:01:43PM -0700, Andrew Morton wrote: > > > On Tue, 23 Apr 2019 15:08:06 +0300 Andrey Ryabinin wrote: > > > > > > > Commit 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake") > > > > removed setting of the ALLOC_NOFRAGMENT flag. Bring it back. > > > > > > What are the runtime effects of this fix? > > > > The runtime effect is that ALLOC_NOFRAGMENT behaviour is restored so > > that allocations are spread across local zones to avoid fragmentation > > due to mixing pageblocks as long as possible. > > OK, thanks. Is this worth a -stable backport? Yes, but only for 5.0 obviously and both should be included if that is the case. I did not push for it initially as problems in this area are hard for a general user to detect and people have not complained about 5.0's fragmentation handling. -- Mel Gorman SUSE Labs