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 36FC9C74A5B for ; Mon, 13 Mar 2023 19:10:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229826AbjCMTKy (ORCPT ); Mon, 13 Mar 2023 15:10:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60704 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230177AbjCMTKn (ORCPT ); Mon, 13 Mar 2023 15:10:43 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B699769C for ; Mon, 13 Mar 2023 12:10:37 -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 dfw.source.kernel.org (Postfix) with ESMTPS id E4C286149D for ; Mon, 13 Mar 2023 19:10:36 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 42E70C433D2; Mon, 13 Mar 2023 19:10:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1678734636; bh=IOzhTzbnfAL0c9ZJfnsWvGtb7IA4tWZ4DGQKu9lzpOg=; h=Date:To:From:Subject:From; b=KzDQdBlgTUIwlDWrj0+ClrZ4oVDp53Z/757Gvc3VZHpyV80RtgXpDygFl/E6wDSt4 EXKfFKa4fv8fN1E9LBjrgIPMKsLwwUwIFw2VSlsDJxpIAiDuqHJSaKudbcltmJAx3U LjdH+pwg/0Lizb6E26ytCaaD+Dt7CNjrJpnOpJIU= Date: Mon, 13 Mar 2023 12:10:35 -0700 To: mm-commits@vger.kernel.org, vbabka@suse.cz, tkhai@ya.ru, sultan@kerneltoast.com, shy828301@gmail.com, shakeelb@google.com, 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, christian.koenig@amd.com, 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: <20230313191036.42E70C433D2@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: Mon, 13 Mar 2023 19:28:17 +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/20230313112819.38938-7-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Vlastimil Babka Acked-by: Kirill Tkhai Cc: Christian König Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Johannes Weiner Cc: Michal Hocko 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 --- --- a/mm/vmscan.c~mm-vmscan-hold-write-lock-to-reparent-shrinker-nr_deferred +++ a/mm/vmscan.c @@ -445,7 +445,7 @@ 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); @@ -454,7 +454,7 @@ 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