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 9E1D5C982EA for ; Wed, 23 Sep 2026 03:41:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9561D6B0093; Tue, 22 Sep 2026 23:41:08 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 906C66B0095; Tue, 22 Sep 2026 23:41:08 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F5D26B0096; Tue, 22 Sep 2026 23:41:08 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 549246B0093 for ; Tue, 22 Sep 2026 23:41:08 -0400 (EDT) Received: from smtpin21.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 4E3FB120675 for ; Wed, 23 Sep 2026 03:41:07 +0000 (UTC) X-FDA: 85243626174.21.7D45A8E Received: from mta0.migadu.com (out-153.mta0.migadu.com [91.218.175.153]) by imf25.hostedemail.com (Postfix) with ESMTP id CBBFFA0005 for ; Wed, 23 Sep 2026 03:41:04 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=t5KzfUbR; spf=pass (imf25.hostedemail.com: domain of hongfu.li@linux.dev designates 91.218.175.153 as permitted sender) smtp.mailfrom=hongfu.li@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=1790134865; 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=YicmoMpBvPwbZSKoyDjZGS1lR6dkUxkLQuwNZdKD4fg=; b=pZnMYu2dIOZBXyxUxc1Mu9jAVWoF4e+BmsX8i87Fg2h974MtlFOCDtVfFW7w88a4QTfRfZ dzXWHczqkVMXjRVlluq0I2h66oHqfPlsj5iTnE/ZMKiYmiyd4jgLjmYsvsdeoBQ4q4KuoZ Aud41NJvi6nPwP+KfoIV8UWiSdvl9Fw= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=t5KzfUbR; spf=pass (imf25.hostedemail.com: domain of hongfu.li@linux.dev designates 91.218.175.153 as permitted sender) smtp.mailfrom=hongfu.li@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1790134865; b=lo2gSAwgh32F8bcbNxzlj/n07WgGGBgVdQnZQvkYX0TKS2EqHB2D8I4caZ1gAolEgsesC+ ZCxH9Hd3mbIKI32ieOJtCGTefWFVVfWpj/0M/vm5wZ7zGtZ8uoSfSLHkAhE7+uur850Bc+ qJQwQKR2AaT0CsAnrf5e8bEhc3It7l0= X-Envelope-To: linux-mm@kvack.org DKIM-Signature: a=rsa-sha256; bh=g0/Z5c9aDwytCwk3EVHISBOUhMOmw+UqfCuabJU23Po=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790134863; v=1; x=1790739663; b=t5KzfUbRPgwv6bU849Gk4sjU/WqthHJxWnYgZ9CznQ3o4Ck0wIbxT85pCzznXxrcJtwcMKwQ DMe4S/Mui0Td3ETfzxqRd45JJF1Q+PDHNHQjSK/l7mYjRq3dJxcyFjZq6B5/J6f/2Xg9tiZtcQL 33KAUZsseBYKCQ+GFiDjP/p4= X-Envelope-To: linux-mm@kvack.org Received: by smtp.migadu.com with ESMTPS id 6f051fd9b05117c8; Wed, 23 Sep 2026 03:41:03 +0000 X-Mizu-Trace-ID: 6f051fd9b05117c8 X-Migadu-Flow: FLOW_OUT Message-ID: <1835413c-e2de-41b0-8225-161afa50676a@linux.dev> Date: Wed, 23 Sep 2026 11:40:55 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: hongfu.li@linux.dev, Chris Down , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, stable@vger.kernel.org, Oscar Salvador , David Hildenbrand , Andrew Morton , Shakeel Butt , Michal Hocko , Johannes Weiner , Joshua Hahn , Nhat Pham , Michal Hocko , Roman Gushchin Subject: Re: [PATCH v2 2/2] mm/memcg: migrate per-node hugetlb lruvec stat together with hugetlb folio To: Muchun Song , Hongfu Li References: <20260923-for-hugetlb_state3-v2-0-e8a36245bfab@kylinos.cn> <20260923-for-hugetlb_state3-v2-2-e8a36245bfab@kylinos.cn> <15ac7069-d687-4985-90bd-25bc900b4bdd@linux.dev> From: Hongfu Li In-Reply-To: <15ac7069-d687-4985-90bd-25bc900b4bdd@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: CBBFFA0005 X-Stat-Signature: 9chjhh5idoz9hud6hid86frjip9jba1k X-HE-Tag: 1790134864-78130 X-HE-Meta: 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 Z2yH5OPY rPW/qQPvZ/klkpOuqJuuq4T6RYp8D34DNVDp1Ti1CVi6mWTXULy1TcRy1bRjpjO6JytZGxIjfLXm2YTh3Tkq2uLDfGAZBrt+3yjbELN7IyoPoDWCE7APmp7VB0vLOh4a2yHFyjHrGq05yChec0Jb6FUmUCSwHmwZ9OIQ8cprDBdvIuo9+2PpYteOdJfqGHNCR27AVkF3Vkare57tkO3UuhyGuZfTH3vgmDPFWobZAbEkf/3r6nGA+zTrMuzGGgQrNFbV6zynWCcJroHwmKzqOvgfPxu9umrKoAcl2C5owqyXzC2ax/wsfL1CG3bd/4hkAe4GnSh9A4uSlnDmBnLYQjm5gAUYqbOkY34uTIxec9coUUEv3XhKUAEPc9B3k/rEvGoajoSjGehiAkgL7hu0Yr0fur4Ea6wkcfX4awBVyo85Fu+I= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 9/23/26 10:40 AM, Muchun Song wrote: > > > On 2026/9/23 10:05, Hongfu Li wrote: >> From: Hongfu Li >> >> memory.numa_stat exposes per-node hugetlb counters from per-node lruvec >> stats. These stats are accounted against folio_nid(): incremented on >> the folio's node when handed to a user, decremented when the folio is >> returned to the pool. >> >> During hugetlb folio migration, mem_cgroup_migrate() moves the charge >> to the new folio and drops the memcg data of the old one, so the free >> of the old folio right after the migration skips the memcg per-node >> lruvec decrement. The hugetlb count stays attributed to the old node >> for the rest of the life of the charge, while the target folio gets no >> increment on the new node; its later free decrements a counter that >> was never incremented. >> >> Migrate the per-node lruvec accounting alongside migration. Global >> memcg totals remain balanced because they track resource consumption, >> not node placement. >> >> Fixes: 05d4532b60e3 ("memcg/hugetlb: add hugeTLB counters to memcg") >> Cc: stable@vger.kernel.org >> Signed-off-by: Hongfu Li >> Tested-by: Joshua Hahn >> Reviewed-by: Joshua Hahn >> Reviewed-by: Oscar Salvador >> --- >>   include/linux/memcontrol.h |  8 ++++++++ >>   mm/hugetlb.c               | 25 +++++++++++++++++++++++++ >>   mm/memcontrol.c            |  5 ++--- >>   3 files changed, 35 insertions(+), 3 deletions(-) >> >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index a8358f297b65..74110a324f9e 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -984,6 +984,9 @@ unsigned long lruvec_page_state_monotonic(const >> struct lruvec *lruvec, >>   unsigned long lruvec_page_state_local(const struct lruvec *lruvec, >>                         enum node_stat_item idx); >>   +void mod_memcg_lruvec_state(struct lruvec *lruvec, >> +                enum node_stat_item idx, int val); >> + >>   void mem_cgroup_flush_stats(struct mem_cgroup *memcg); >>   void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg); >>   @@ -1452,6 +1455,11 @@ static inline unsigned long >> lruvec_page_state_local(const struct lruvec *lruvec, >>       return node_page_state(lruvec_pgdat(lruvec), idx); >>   } >>   +static inline void mod_memcg_lruvec_state(struct lruvec *lruvec, >> +                      enum node_stat_item idx, int val) >> +{ >> +} >> + >>   static inline void mem_cgroup_flush_stats(struct mem_cgroup *memcg) >>   { >>   } >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index 519c30b338a8..76d019594b39 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -23,6 +23,7 @@ >>   #include >>   #include >>   #include >> +#include >>   #include >>   #include >>   #include >> @@ -7378,12 +7379,36 @@ void folio_putback_hugetlb(struct folio *folio) >>       folio_put(folio); >>   } >>   +static void move_hugetlb_lruvec_stat(struct folio *old_folio, >> +                     struct folio *new_folio) >> +{ >> +    struct mem_cgroup *memcg; >> +    long nr_pages = folio_nr_pages(old_folio); >> +    int old_nid = folio_nid(old_folio); >> +    int new_nid = folio_nid(new_folio); >> + >> +    if (old_nid == new_nid) >> +        return; >> + >> +    guard(rcu)(); >> + >> +    memcg = folio_memcg(new_folio); >> +    if (!memcg) >> +        return; >> + >> +    mod_memcg_lruvec_state(mem_cgroup_lruvec(memcg, >> NODE_DATA(old_nid)), >> +                   NR_HUGETLB, -nr_pages); > > Why not use mod_lruvec_state? mod_memcg_lruvec_state is an internal > API for memcg, I don't want it to be exported. Thank you for the review. mod_lruvec_state() would update the node counter a second time.  It calls mod_node_page_state() as well, and the target's node counter is already updated in alloc_hugetlb_folio_nodemask() (patch 1/2):     lruvec_stat_mod_folio(folio, NR_HUGETLB, folio_nr_pages(folio)); For an uncharged folio lruvec_stat_mod_folio() only updates the node counter.  The target folio is not charged to any memcg at that point; its charge only appears later in mem_cgroup_migrate().  So the node side is already covered and only the per-memcg attribution has to follow the charge here. > > Thanks. > >> + mod_memcg_lruvec_state(mem_cgroup_lruvec(memcg, NODE_DATA(new_nid)), >> +                   NR_HUGETLB, nr_pages); >> +} >> + >>   void move_hugetlb_state(struct folio *old_folio, struct folio >> *new_folio, >>               enum migrate_reason reason) >>   { >>       struct hstate *h = folio_hstate(old_folio); >>         hugetlb_cgroup_migrate(old_folio, new_folio); >> +    move_hugetlb_lruvec_stat(old_folio, new_folio); >>       folio_set_owner_migrate_reason(new_folio, reason); >>         /* >> diff --git a/mm/memcontrol.c b/mm/memcontrol.c >> index 88824f783571..a5335da5d425 100644 >> --- a/mm/memcontrol.c >> +++ b/mm/memcontrol.c >> @@ -1015,9 +1015,8 @@ static void __mod_memcg_lruvec_state(struct >> mem_cgroup_per_node *pn, >>       put_cpu(); >>   } >>   -static void mod_memcg_lruvec_state(struct lruvec *lruvec, >> -                     enum node_stat_item idx, >> -                     int val) >> +void mod_memcg_lruvec_state(struct lruvec *lruvec, >> +                enum node_stat_item idx, int val) >>   { >>       struct pglist_data *pgdat = lruvec_pgdat(lruvec); >>       struct mem_cgroup_per_node *pn; >> > -- Best regards, Hongfu