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 A1ED6C6FD1E for ; Tue, 7 Mar 2023 22:27:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229933AbjCGW1d (ORCPT ); Tue, 7 Mar 2023 17:27:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230143AbjCGW0t (ORCPT ); Tue, 7 Mar 2023 17:26:49 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B23F697B74 for ; Tue, 7 Mar 2023 14:26:23 -0800 (PST) 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 sin.source.kernel.org (Postfix) with ESMTPS id 9ED68CE1D58 for ; Tue, 7 Mar 2023 22:25:32 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F222EC433EF; Tue, 7 Mar 2023 22:25:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1678227931; bh=IOLTQgpru9x7C16Gliyd+1U7bvPc+eRjwvqTLRMzyr0=; h=Date:To:From:Subject:From; b=pZhpqvBDTXyrkpS0c2yX2NgYYWUna9usKy6cXjHm9CNTQvMK4fjDA7QnVFEqKV0QC ov2LUermFxjlSJiHkkWpK1DuaPRNbQ7O/LQnKkiZgYHWrXayaBu7lscsVSQxqIn7IJ UtwEs/I9qF+S7Lo+dUuTygnD8ddfaZheKRU53rzU= Date: Tue, 07 Mar 2023 14:25:30 -0800 To: mm-commits@vger.kernel.org, tkhai@ya.ru, sultan@kerneltoast.com, shy828301@gmail.com, shakeelb@google.com, rppt@kernel.org, roman.gushchin@linux.dev, penguin-kernel@i-love.sakura.ne.jp, paulmck@kernel.org, muchun.song@linux.dev, mhocko@kernel.org, hannes@cmpxchg.org, david@redhat.com, dave@stgolabs.net, zhengqi.arch@bytedance.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch added to mm-unstable branch Message-Id: <20230307222530.F222EC433EF@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: vmscan: hold write lock to reparent shrinker nr_deferred has been added to the -mm mm-unstable branch. Its filename is mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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 via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Qi Zheng Subject: mm: vmscan: hold write lock to reparent shrinker nr_deferred Date: Tue, 7 Mar 2023 14:56:03 +0800 For now, reparent_shrinker_deferred() is the only holder of read lock of shrinker_rwsem. And it already holds the global cgroup_mutex, so it will not be called in parallel. Therefore, in order to convert shrinker_rwsem to shrinker_mutex later, here we change to hold the write lock of shrinker_rwsem to reparent. Link: https://lkml.kernel.org/r/20230307065605.58209-7-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Johannes Weiner Cc: Kirill Tkhai Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Paul E. McKenney Cc: Roman Gushchin Cc: Shakeel Butt Cc: Sultan Alsawaf Cc: Tetsuo Handa Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/vmscan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/vmscan.c~mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred +++ a/mm/vmscan.c @@ -451,7 +451,7 @@ void reparent_shrinker_deferred(struct m parent = root_mem_cgroup; /* Prevent from concurrent shrinker_info expand */ - down_read(&shrinker_rwsem); + down_write(&shrinker_rwsem); for_each_node(nid) { child_info = shrinker_info_protected(memcg, nid); parent_info = shrinker_info_protected(parent, nid); @@ -460,7 +460,7 @@ void reparent_shrinker_deferred(struct m atomic_long_add(nr, &parent_info->nr_deferred[i]); } } - up_read(&shrinker_rwsem); + up_write(&shrinker_rwsem); } static bool cgroup_reclaim(struct scan_control *sc) _ Patches currently in -mm which might be from zhengqi.arch@bytedance.com are mm-vmscan-add-a-map_nr_max-field-to-shrinker_info.patch mm-vmscan-make-global-slab-shrink-lockless.patch mm-vmscan-make-memcg-slab-shrink-lockless.patch mm-shrinkers-make-count-and-scan-in-shrinker-debugfs-lockless.patch mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred.patch mm-vmscan-remove-shrinker_rwsem-from-synchronize_shrinkers.patch mm-shrinkers-convert-shrinker_rwsem-to-mutex.patch