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=-9.8 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,USER_AGENT_GIT 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 5A255C63798 for ; Tue, 17 Nov 2020 13:45:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F30CC24199 for ; Tue, 17 Nov 2020 13:45:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="cl2kbsXR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732852AbgKQNon (ORCPT ); Tue, 17 Nov 2020 08:44:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:52224 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732839AbgKQNkQ (ORCPT ); Tue, 17 Nov 2020 08:40:16 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 D5C672467A; Tue, 17 Nov 2020 13:40:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605620414; bh=EHQecxWPq1uWQiw5Yjqw1rkWg0rgmJwKmTJ1M1SfG/U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cl2kbsXRKR0LRgPm9Cd7iQQgxxDu/Jf/jA+pw52lW27F5f3zIB12pRVWBpqEDhvim vlkpDnNXBpu/2/zd2SWXxjAz0ah6JQpDm83mA8MxLfoaxjAOMX6Y4GgdZ4XsLTVSl7 Pg31Iv5UHyyg8uq4a4GvVMklnQH/QgLegTMA429I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vlastimil Babka , Zi Yan , Andrew Morton , Mel Gorman , Michal Hocko , Rik van Riel , Yang Shi , Linus Torvalds Subject: [PATCH 5.9 210/255] mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate Date: Tue, 17 Nov 2020 14:05:50 +0100 Message-Id: <20201117122149.156459162@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122138.925150709@linuxfoundation.org> References: <20201117122138.925150709@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zi Yan commit d20bdd571ee5c9966191568527ecdb1bd4b52368 upstream. 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] Fixes: 1da2f328fa64 (“mm,thp,compaction,cma: allow THP migration for CMA allocations”) Suggested-by: Vlastimil Babka Signed-off-by: Zi Yan Signed-off-by: Andrew Morton Cc: Cc: Mel Gorman Cc: Michal Hocko Cc: Rik van Riel Cc: Yang Shi Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/compaction.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/compaction.c +++ b/mm/compaction.c @@ -818,6 +818,10 @@ 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 == MIGRATE_ASYNC) return 0;