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 9980AC433F5 for ; Fri, 1 Apr 2022 01:11:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229589AbiDABN1 (ORCPT ); Thu, 31 Mar 2022 21:13:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239082AbiDABN0 (ORCPT ); Thu, 31 Mar 2022 21:13:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4036F236BB8 for ; Thu, 31 Mar 2022 18:11:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id CDAA0B822B1 for ; Fri, 1 Apr 2022 01:11:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6DBF8C340EE; Fri, 1 Apr 2022 01:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1648775495; bh=V1Cd+4tfMSrD4EshodDcrTyIpQ8nyzICR6Alw3BhmgY=; h=Date:To:From:Subject:From; b=gdtyi0cKqpkL9qtm/b4ERf3ypDpltYVaIeNXPgthRmb7iOSlzE0Ln7MXmFC78Yybu q/4ZOa2rHfuOvqYobXximPx/Rlh9iaGwSMCsxYXHpVLy9K51xVBpUgOHwzGRrkYGPi 3TmpExdoYXMwNYAPTKRSsooFTlWxTy6B6g8Tferc= Date: Thu, 31 Mar 2022 18:11:34 -0700 To: mm-commits@vger.kernel.org, songmuchun@bytedance.com, shakeelb@google.com, roman.gushchin@linux.dev, mhocko@suse.com, longman@redhat.com, hannes@cmpxchg.org, akpm@linux-foundation.org, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node.patch added to -mm tree Message-Id: <20220401011135.6DBF8C340EE@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/list_lru.c: revert "mm/list_lru: optimize memcg_reparent_list_lru_node()" has been added to the -mm tree. Its filename is mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrew Morton Subject: mm/list_lru.c: revert "mm/list_lru: optimize memcg_reparent_list_lru_node()" 405cc51fc1049c73 ("mm/list_lru: optimize memcg_reparent_list_lru_node()") has subtle races which are proving ugly to fix. Revert the original optimization. If quantitative testing indicates that we have a significant problem here then other implementations can be looked at. Fixes: 405cc51fc1049c73 ("mm/list_lru: optimize memcg_reparent_list_lru_node()") Cc: Waiman Long Cc: Roman Gushchin Cc: Muchun Song Cc: Michal Hocko Cc: Johannes Weiner Cc: Shakeel Butt Signed-off-by: Andrew Morton --- mm/list_lru.c | 6 ------ 1 file changed, 6 deletions(-) --- a/mm/list_lru.c~mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node +++ a/mm/list_lru.c @@ -395,12 +395,6 @@ static void memcg_reparent_list_lru_node struct list_lru_one *src, *dst; /* - * If there is no lru entry in this nlru, we can skip it immediately. - */ - if (!READ_ONCE(nlru->nr_items)) - return; - - /* * Since list_lru_{add,del} may be called under an IRQ-safe lock, * we have to use IRQ-safe primitives here to avoid deadlock. */ _ Patches currently in -mm which might be from akpm@linux-foundation.org are mm-list_lruc-revert-mm-list_lru-optimize-memcg_reparent_list_lru_node.patch mm.patch mm-shmem-make-shmem_init-return-void-fix.patch ksm-count-ksm-merging-pages-for-each-process-fix.patch mm-memory_hotplug-refactor-hotadd_init_pgdat-and-try_online_node-checkpatch-fixes.patch proc-fix-dentry-inode-overinstantiating-under-proc-pid-net-checkpatch-fixes.patch fs-proc-kcorec-remove-check-of-list-iterator-against-head-past-the-loop-body-fix.patch add-fat-messages-to-printk-index-checkpatch-fixes.patch linux-next-rejects.patch linux-next-git-rejects.patch mm-oom_killc-fix-vm_oom_kill_table-ifdeffery.patch b.patch