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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BAEFEDE99E for ; Thu, 14 Sep 2023 10:03:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237877AbjINKDO (ORCPT ); Thu, 14 Sep 2023 06:03:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237848AbjINKDN (ORCPT ); Thu, 14 Sep 2023 06:03:13 -0400 Received: from outbound-smtp16.blacknight.com (outbound-smtp16.blacknight.com [46.22.139.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3DB01BF9 for ; Thu, 14 Sep 2023 03:03:07 -0700 (PDT) Received: from mail.blacknight.com (pemlinmail04.blacknight.ie [81.17.254.17]) by outbound-smtp16.blacknight.com (Postfix) with ESMTPS id A5C9A1C3D57 for ; Thu, 14 Sep 2023 11:03:06 +0100 (IST) Received: (qmail 24834 invoked from network); 14 Sep 2023 10:03:06 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.197.19]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 14 Sep 2023 10:03:06 -0000 Date: Thu, 14 Sep 2023 11:03:04 +0100 From: Mel Gorman To: Johannes Weiner Cc: Andrew Morton , Vlastimil Babka , Miaohe Lin , Kefeng Wang , Zi Yan , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/6] mm: page_alloc: move free pages when converting block during isolation Message-ID: <20230914100304.v7ztao3rz6ubp6o3@techsingularity.net> References: <20230911195023.247694-1-hannes@cmpxchg.org> <20230911195023.247694-4-hannes@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20230911195023.247694-4-hannes@cmpxchg.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 11, 2023 at 03:41:44PM -0400, Johannes Weiner wrote: > When claiming a block during compaction isolation, move any remaining > free pages to the correct freelists as well, instead of stranding them > on the wrong list. Otherwise, this encourages incompatible page mixing > down the line, and thus long-term fragmentation. > > Signed-off-by: Johannes Weiner Hmm, this is potentially expensive in some cases but it's also correct. Given how expensive the whole path is, I doubt it's noticable and some of this activity will be !direct_compaction anyway and relatively invisible even if I'm not a fan of hiding overhead in kthreads. Either way; Acked-by: Mel Gorman -- Mel Gorman SUSE Labs