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 47095C433E7 for ; Tue, 13 Oct 2020 23:55:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08D6B22203 for ; Tue, 13 Oct 2020 23:55:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633323; bh=QSmBtJDroo6Z4D+HXWjvM0StAuYY7GUmTabPVQPGV08=; h=Date:From:To:Subject:In-Reply-To:Reply-To:List-ID:From; b=eyLl3OVuaWifbpnlrCcDjbt9a3piDkrRTr210ZIJL95ioPhQQQ4UJZ4190r46wQtD u4pXzDjx+egioD4t6afiM7Dbt1PMHuN+G+n4M2ggIcU9Ww5bAqa/+qCWjAVuzn93th AMgHelm2HiYo2vYfZZoE4rlmmLdybQcfjDU178YU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388465AbgJMXzW (ORCPT ); Tue, 13 Oct 2020 19:55:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:40698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388463AbgJMXzW (ORCPT ); Tue, 13 Oct 2020 19:55:22 -0400 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 8394E208B3; Tue, 13 Oct 2020 23:55:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602633322; bh=QSmBtJDroo6Z4D+HXWjvM0StAuYY7GUmTabPVQPGV08=; h=Date:From:To:Subject:In-Reply-To:From; b=q57F0yOHAdJcT7un1Slpzn161xxli/HE+8I5dj8C6nmBfHX1unVN4gLCNmkMcHOrs 1JegdjdeRYpal0LmcxxWEeC2M0AF3dBAvd2EEhU04EmwcYIHXVRkzZkg2kgJLzTXnp 8hgEEya9+jO0LHC+XekAa+tfU5wC1m2gd4/cAuv8= Date: Tue, 13 Oct 2020 16:55:21 -0700 From: Andrew Morton To: akpm@linux-foundation.org, bhe@redhat.com, cai@lca.pw, david@redhat.com, jasowang@redhat.com, linux-mm@kvack.org, mhocko@suse.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, mst@redhat.com, pankaj.gupta.linux@gmail.com, rppt@kernel.org, torvalds@linux-foundation.org Subject: [patch 126/181] mm/page_isolation: exit early when pageblock is isolated in set_migratetype_isolate() Message-ID: <20201013235521.z0NNxC9EO%akpm@linux-foundation.org> In-Reply-To: <20201013164658.3bfd96cc224d8923e66a9f4e@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org From: David Hildenbrand Subject: mm/page_isolation: exit early when pageblock is isolated in set_migratetype_isolate() Right now, if we have two isolations racing on a pageblock that's in the MOVABLE zone, we would trigger the WARN_ON_ONCE(). Let's just return directly, simplifying error handling. The change was introduced in commit 3d680bdf60a5 ("mm/page_isolation: fix potential warning from user"). As far as I can see, we currently don't have alloc_contig_range() users that use the ZONE_MOVABLE (anymore), so it's currently more a cleanup and a preparation for the future than a fix. Link: http://lkml.kernel.org/r/20200816125333.7434-3-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Baoquan He Reviewed-by: Pankaj Gupta Acked-by: Mike Kravetz Cc: Michal Hocko Cc: Michael S. Tsirkin Cc: Qian Cai Cc: Jason Wang Cc: Mike Rapoport Signed-off-by: Andrew Morton --- mm/page_isolation.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/mm/page_isolation.c~mm-page_isolation-exit-early-when-pageblock-is-isolated-in-set_migratetype_isolate +++ a/mm/page_isolation.c @@ -29,10 +29,12 @@ static int set_migratetype_isolate(struc /* * We assume the caller intended to SET migrate type to isolate. * If it is already set, then someone else must have raced and - * set it before us. Return -EBUSY + * set it before us. */ - if (is_migrate_isolate_page(page)) - goto out; + if (is_migrate_isolate_page(page)) { + spin_unlock_irqrestore(&zone->lock, flags); + return -EBUSY; + } /* * FIXME: Now, memory hotplug doesn't call shrink_slab() by itself. @@ -52,7 +54,6 @@ static int set_migratetype_isolate(struc ret = 0; } -out: spin_unlock_irqrestore(&zone->lock, flags); if (!ret) { drain_all_pages(zone); _