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=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 45AE8C6369E for ; Sat, 14 Nov 2020 06:51:47 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id DBAFD2064B for ; Sat, 14 Nov 2020 06:51:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xJ/bJfVi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DBAFD2064B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7CB5C6B006E; Sat, 14 Nov 2020 01:51:46 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 77C236B0070; Sat, 14 Nov 2020 01:51:46 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 66BA46B0071; Sat, 14 Nov 2020 01:51:46 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0177.hostedemail.com [216.40.44.177]) by kanga.kvack.org (Postfix) with ESMTP id 39F506B006E for ; Sat, 14 Nov 2020 01:51:46 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id CF2F3180AD806 for ; Sat, 14 Nov 2020 06:51:45 +0000 (UTC) X-FDA: 77482103370.05.glue56_0a0998527315 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin05.hostedemail.com (Postfix) with ESMTP id B351218023EA5 for ; Sat, 14 Nov 2020 06:51:45 +0000 (UTC) X-HE-Tag: glue56_0a0998527315 X-Filterd-Recvd-Size: 3303 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Sat, 14 Nov 2020 06:51:45 +0000 (UTC) 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 E744120678; Sat, 14 Nov 2020 06:51:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605336704; bh=7A8xRWjoWPWC9KyJ6x3rmRUQXiSqxG75ANllE40gtLo=; h=Date:From:To:Subject:In-Reply-To:From; b=xJ/bJfViHVB1I9bXIA4pxqZUlnb8SqqJNl1dmDc+0iHh8SxpA+KWzPufRmOaO88Gw yzSjQJAiA7dPpFhDnFpiXuho2A44Oh1rs9X66w1b64OjxIfbeRuP39TQz6SDZKDzKE Gk0ShjhRP6crlzgDn/0AvG0EwXkjtiGGEkJkgsBY= Date: Fri, 13 Nov 2020 22:51:43 -0800 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mgorman@techsingularity.net, mhocko@kernel.org, mm-commits@vger.kernel.org, riel@surriel.com, shy828301@gmail.com, stable@vger.kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz, ziy@nvidia.com Subject: [patch 02/14] mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate Message-ID: <20201114065143.mF1DRNoun%akpm@linux-foundation.org> In-Reply-To: <20201113225115.b24faebc85f710d5aff55aa7@linux-foundation.org> User-Agent: s-nail v14.8.16 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =46rom: Zi Yan Subject: mm/compaction: stop isolation if too many pages are isolated and w= e have pages to migrate In isolate_migratepages_block, if we have too many isolated pages and nr_migratepages is not zero, we should try to migrate what we have without wasting time on isolating. In theory it's possible that multiple parallel compactions will cause too_many_isolated() to become true even if each has isolated less than COMPACT_CLUSTER_MAX, and loop forever in the while loop. Bailing immediately prevents that. [vbabka@suse.cz: changelog addition] Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.com Fixes: 1da2f328fa64 (=E2=80=9Cmm,thp,compaction,cma: allow THP migration fo= r CMA allocations=E2=80=9D) Signed-off-by: Zi Yan Suggested-by: Vlastimil Babka Cc: Cc: Mel Gorman Cc: Michal Hocko Cc: Rik van Riel Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/compaction.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/compaction.c~mm-compaction-stop-isolation-if-too-many-pages-are-is= olated-and-we-have-pages-to-migrate +++ a/mm/compaction.c @@ -817,6 +817,10 @@ isolate_migratepages_block(struct compac * delay for some time until fewer pages are isolated */ while (unlikely(too_many_isolated(pgdat))) { + /* stop isolation if there are still pages not migrated */ + if (cc->nr_migratepages) + return 0; + /* async migration should just abort */ if (cc->mode =3D=3D MIGRATE_ASYNC) return 0; _