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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B13DAFD461F for ; Thu, 26 Feb 2026 06:46:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0554D6B0088; Thu, 26 Feb 2026 01:46:02 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F1BB76B0089; Thu, 26 Feb 2026 01:46:01 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E1D166B0092; Thu, 26 Feb 2026 01:46:01 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id CFA406B0088 for ; Thu, 26 Feb 2026 01:46:01 -0500 (EST) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5ECECC311C for ; Thu, 26 Feb 2026 06:46:01 +0000 (UTC) X-FDA: 84485672922.12.C6A2EC8 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) by imf20.hostedemail.com (Postfix) with ESMTP id 8E03B1C0009 for ; Thu, 26 Feb 2026 06:45:59 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=fqwCC+zh; spf=pass (imf20.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772088359; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=C4rL/wwllg6CU5AzOZho/BUjc41JirXfRLVAIZITAog=; b=kTOHfnUgM6ueBwJ3H+rkvRtBoQ/z+b70ZQUtfbVpYbowy916HJ/9ZhzRZcdGu52nkUnyRC zP0g6UchRkR246u5iuScmAyxzooQHJP5ddWJCBRlcjxyInMNGmITXAxF0ZAHur/LFGU054 3FRytJoe76WNM18AO0UmEnD1SkwlqL4= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=fqwCC+zh; spf=pass (imf20.hostedemail.com: domain of qi.zheng@linux.dev designates 91.218.175.178 as permitted sender) smtp.mailfrom=qi.zheng@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772088359; a=rsa-sha256; cv=none; b=MSiHPTVayblrb9M0/1HfI1xoCQn8NsjNeg7dP3xS2Pnb6p4j3w01rFFG4dSO6tm4NvHrA1 egHUuDwh8kKB3JhOIBSCJ8mhQObWGGjlTv5E4Ezqnf8hjb63qPJY7aQFqNzEjFzZXO8teU oBhXhtSSogHQKfgNVkRlar8cbLPTSI4= Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772088357; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C4rL/wwllg6CU5AzOZho/BUjc41JirXfRLVAIZITAog=; b=fqwCC+zho2n+4/p9/dwF/Zeky6wKhrtDbuYw1zzSrKqzghBSWcypfO12waZoixPntWyd45 WYrm3j6GECj3OS1oxAzopUY1P1+JNiN5ZEXDRr/Oa1k/Ir5/biWrClmwF7xAkvmnc6nRP6 nZ/FW3jXXhmkxVqNOAPdkrxYdwl9SBk= Date: Thu, 26 Feb 2026 14:45:46 +0800 MIME-Version: 1.0 Subject: Re: [PATCH v5 29/32] mm: memcontrol: prepare for reparenting non-hierarchical stats To: Shakeel Butt Cc: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, muchun.song@linux.dev, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, yosry.ahmed@linux.dev, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev, bhe@redhat.com, usamaarif642@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Qi Zheng References: X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Qi Zheng In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: eikxdhwhhj188ys4k6rojgsst6bwdrfy X-Rspamd-Server: rspam11 X-Rspam-User: X-Rspamd-Queue-Id: 8E03B1C0009 X-HE-Tag: 1772088359-966147 X-HE-Meta: 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 ++HlQdFx zP3sLVvUWrofG/lFO+TLQPLxaJY6ixW9Wp3AZuefKEE91raRzVWKCL3Mq47LtTusDdtKXK+mWRtYd6gHRGH9cdWY++H1zKPiVZ+wc8R4cM8Dv3+vRfnUmSvB6y6OcsWhyBKk1tUkmasE8tvyUOHOU6ULz/MUR6w7nxzjG3M61HRbvJHec1EuXE9rAKQPgxoFvwATPwlUCakCJwVH+r1dhMhovrDpObup0dSTEx/WZS3gCgELVr+PVuu32bCqSlGUpG5r/BfzV3jTOz9BVGBnzL3Uuyw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2/26/26 9:41 AM, Shakeel Butt wrote: > On Wed, Feb 25, 2026 at 03:53:12PM +0800, Qi Zheng wrote: >> From: Qi Zheng >> >> To resolve the dying memcg issue, we need to reparent LRU folios of child >> memcg to its parent memcg. This could cause problems for non-hierarchical >> stats. >> >> As Yosry Ahmed pointed out: >> >> ``` >> In short, if memory is charged to a dying cgroup at the time of >> reparenting, when the memory gets uncharged the stats updates will occur >> at the parent. This will update both hierarchical and non-hierarchical >> stats of the parent, which would corrupt the parent's non-hierarchical >> stats (because those counters were never incremented when the memory was >> charged). >> ``` >> >> Now we have the following two types of non-hierarchical stats, and they >> are only used in CONFIG_MEMCG_V1: >> >> a. memcg->vmstats->state_local[i] >> b. pn->lruvec_stats->state_local[i] >> >> To ensure that these non-hierarchical stats work properly, we need to >> reparent these non-hierarchical stats after reparenting LRU folios. To >> this end, this commit makes the following preparations: >> >> 1. implement reparent_state_local() to reparent non-hierarchical stats >> 2. make css_killed_work_fn() to be called in rcu work, and implement >> get_non_dying_memcg_start() and get_non_dying_memcg_end() to avoid race >> between mod_memcg_state()/mod_memcg_lruvec_state() >> and reparent_state_local() >> 3. change these non-hierarchical stats to atomic_long_t type to avoid race >> between mem_cgroup_stat_aggregate() and reparent_state_local() >> >> Signed-off-by: Qi Zheng > > [...] > >> --- a/mm/memcontrol-v1.h >> +++ b/mm/memcontrol-v1.h >> @@ -45,6 +45,7 @@ static inline bool do_memsw_account(void) >> >> unsigned long memcg_events_local(struct mem_cgroup *memcg, int event); >> unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx); >> +void mod_memcg_page_state_local(struct mem_cgroup *memcg, int idx, unsigned long val); > > The above seems like addition by mistake. Yes, my mistake, need to be deleted directly. ;) > > After fixing this, you can add: > > Acked-by: Shakeel Butt Thanks! >