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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E0598C433E0 for ; Fri, 19 Mar 2021 13:21:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E46264EEE for ; Fri, 19 Mar 2021 13:21:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229941AbhCSNU3 (ORCPT ); Fri, 19 Mar 2021 09:20:29 -0400 Received: from mx2.suse.de ([195.135.220.15]:49432 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229736AbhCSNUT (ORCPT ); Fri, 19 Mar 2021 09:20:19 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id BE1DBACFC; Fri, 19 Mar 2021 13:20:18 +0000 (UTC) From: Oscar Salvador To: Andrew Morton Cc: Mike Kravetz , Vlastimil Babka , David Hildenbrand , Michal Hocko , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador , Michal Hocko Subject: [PATCH v6 1/5] mm,page_alloc: Bail out earlier on -ENOMEM in alloc_contig_migrate_range Date: Fri, 19 Mar 2021 14:20:00 +0100 Message-Id: <20210319132004.4341-2-osalvador@suse.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20210319132004.4341-1-osalvador@suse.de> References: <20210319132004.4341-1-osalvador@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, __alloc_contig_migrate_range can generate -EINTR, -ENOMEM or -EBUSY, and report them down the chain. The problem is that when migrate_pages() reports -ENOMEM, we keep going till we exhaust all the try-attempts (5 at the moment) instead of bailing out. migrate_pages() bails out right away on -ENOMEM because it is considered a fatal error. Do the same here instead of keep going and retrying. Note that this is not fixing a real issue, just a cosmetic change. Although we can save some cycles by backing off ealier Signed-off-by: Oscar Salvador Acked-by: Vlastimil Babka Reviewed-by: David Hildenbrand Acked-by: Michal Hocko --- mm/page_alloc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index cfc72873961d..a4f67063b85f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -8481,7 +8481,7 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, } tries = 0; } else if (++tries == 5) { - ret = ret < 0 ? ret : -EBUSY; + ret = -EBUSY; break; } @@ -8491,6 +8491,12 @@ static int __alloc_contig_migrate_range(struct compact_control *cc, ret = migrate_pages(&cc->migratepages, alloc_migration_target, NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE); + /* + * On -ENOMEM, migrate_pages() bails out right away. It is pointless + * to retry again over this error, so do the same here. + */ + if (ret == -ENOMEM) + break; } if (ret < 0) { putback_movable_pages(&cc->migratepages); -- 2.16.3