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 D605BFD4606 for ; Thu, 26 Feb 2026 01:42:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 300426B0088; Wed, 25 Feb 2026 20:42:04 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2ADD96B008C; Wed, 25 Feb 2026 20:42:04 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 185DC6B0092; Wed, 25 Feb 2026 20:42:04 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 0247C6B0088 for ; Wed, 25 Feb 2026 20:42:03 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id ABAF71A021E for ; Thu, 26 Feb 2026 01:42:03 +0000 (UTC) X-FDA: 84484906926.30.90227A1 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) by imf07.hostedemail.com (Postfix) with ESMTP id D3EE24000A for ; Thu, 26 Feb 2026 01:42:01 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=DBpR2vEH; spf=pass (imf07.hostedemail.com: domain of shakeel.butt@linux.dev designates 95.215.58.186 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772070122; a=rsa-sha256; cv=none; b=q4XjRlMmtCXOCq0Yc6Oc8B/9YB/VZ7GvfUV0xaduvWeFQWTCy6vKl04dStEDuJ0rW++zpb 9NQrvL/Ez1aG4at2qouRZruhdt8GL/J0ItONRVBUtjqt5IV5uphnQ03Nph9nBk32RMYCld Uu5Wjmf7+K8Sbp1vInUldi1+a5aCKmM= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=DBpR2vEH; spf=pass (imf07.hostedemail.com: domain of shakeel.butt@linux.dev designates 95.215.58.186 as permitted sender) smtp.mailfrom=shakeel.butt@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=1772070122; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=FCvGmCmilt3Iav7ktXIbGgvFCADiAsVJLuTgICHbbvU=; b=kYBHnVI+VZU9J1uk6JcPOl1sfMT6CjF2pzH5HGDiO8jqgoTOzLpkA2VsrbfxuOXnijkg65 oOEIicrU0m8oYSbdLJtV7wHrQh7A3BlX+dZdHYZVwwtSTsOb/cZyddkPckZYPocrLHlGPh EJukUdSQEFtnBKQt73RT2RnxGATMyws= Date: Wed, 25 Feb 2026 17:41:46 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772070116; 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: in-reply-to:in-reply-to:references:references; bh=FCvGmCmilt3Iav7ktXIbGgvFCADiAsVJLuTgICHbbvU=; b=DBpR2vEHIC7mO2TzWh+tPoXu1M0seTK3lc9QNrkr4WCCR0KRQGf/X0U8dUG6eoOfO/W5Eo QoZ6Lz1NfN4dRNNpPK000BXyGzhaRdY9c2l3lawHKeoxcAk42kCxcc5L15Bmf2X39OjXIS Ufk8H2HzfJmRbO1VmozjxmiaJ7e4so4= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Shakeel Butt To: Qi Zheng 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 Subject: Re: [PATCH v5 29/32] mm: memcontrol: prepare for reparenting non-hierarchical stats Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: D3EE24000A X-Stat-Signature: rabq8wrewzgpsducxuyhox97k1kpwd1n X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1772070121-654007 X-HE-Meta: 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 BvHKVUzC fy0YIKQcn2wK2ph7OsTzLxPUCv8luDN40O+9kXR/otefdvF7UzNDwHBrYVez3h5fExIK1BSOvLfFzpt6nfJu+RNIeqcpRXRgdBZ3wUei5HnV2hvC1Zj/CErb3dih0VXM7hFTy2Bojvy0h4iTT4+KcEzz+w32qBcbDpiXt375YuO7PtBFT23poBCY1o1RNuyhJwuMxoCvOADZRs1KNQDI9XGPtTjM2bscV33sIGnXO/P8awIz7QWalJjm1fBwd+EHg7vv4aMp8LvfRmkw= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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. After fixing this, you can add: Acked-by: Shakeel Butt