From nobody Thu Apr 2 18:43:38 2026 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC29D3AA4ED for ; Fri, 27 Mar 2026 10:17:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774606623; cv=none; b=W7WtdjgBYElGtd7/Nz/tuyxDD2QzeL8C1LHD4TwlzD9JRh2oXN4NB/v20wDm8yDFpgugdqw28WSL3lYzwPATlEqGhlJTGBk/6wBrSMk4jY6MF/CKgunWBH82e9mI/zSdlVv6LBxWg8VaHTVhPizjxPvhjG/1fQ451zIb6NiSvRc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774606623; c=relaxed/simple; bh=FChlusAg2keKtlQqNvSV4CBx+lY1rF07+OF5HwfKDxg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h+pDROMNGjpCSuRZXxl/FTNHGP1395Pk24wauI0gFiGCQh1dgjHYPxECHICIVjre+zSY/1hw/M/UJoy1ADgfTs+/3zx0opjR5T+mDB9zdgcumqzUjyNujs79GxJLPRRGtJ4YeC4tClABcUD9a3wDzPD8+7zbNG8rNiP1cK51bvc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=n7etKLiZ; arc=none smtp.client-ip=95.215.58.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="n7etKLiZ" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1774606619; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3Goj2w/XvX2fuIVw9KmHpMrros6oROepUqCQ10lc9aw=; b=n7etKLiZxHhpFOAJwSDC/lgn1t/0yHC/rGmzxUeTDg/IPtxY7A79rsV54HZBom8pfN2fQN Nm7TSdTkpDI2z1ZgpgHOqU7amDU9vq8fqcgoOt1HWv++g4L/0DLzFZtFbE+uuYeg7fiA1m vBWkW8nj0VfsYJKwLT383Mfn8Qi5UAQ= From: Qi Zheng To: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@kernel.org, ljs@kernel.org, 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 Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qi Zheng Subject: [PATCH v3 1/3] mm: memcontrol: correct the type of stats_updates to unsigned long Date: Fri, 27 Mar 2026 18:16:28 +0800 Message-ID: In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Qi Zheng The memcg_rstat_updated() tracks updates for vmstats_percpu->state and lruvec_stats_percpu->state. Since these state values are of type long, change the val parameter passed to memcg_rstat_updated() to long as well. Correspondingly, change the type of stats_updates in struct memcg_vmstats_percpu and struct memcg_vmstats from unsigned int and atomic_t to unsigned long and atomic_long_t respectively to prevent potential overflow when handling large state updates during the reparenting of LRU folios. Signed-off-by: Qi Zheng Reviewed-by: Lorenzo Stoakes (Oracle) Acked-by: Zi Yan Reviewed-by: Harry Yoo (Oracle) --- mm/memcontrol.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index ac7b46c4d67e4..3daab9b46429a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -608,7 +608,7 @@ static inline int memcg_events_index(enum vm_event_item= idx) =20 struct memcg_vmstats_percpu { /* Stats updates since the last flush */ - unsigned int stats_updates; + unsigned long stats_updates; =20 /* Cached pointers for fast iteration in memcg_rstat_updated() */ struct memcg_vmstats_percpu __percpu *parent_pcpu; @@ -639,7 +639,7 @@ struct memcg_vmstats { unsigned long events_pending[NR_MEMCG_EVENTS]; =20 /* Stats updates since the last flush */ - atomic_t stats_updates; + atomic_long_t stats_updates; }; =20 /* @@ -665,16 +665,16 @@ static u64 flush_last_time; =20 static bool memcg_vmstats_needs_flush(struct memcg_vmstats *vmstats) { - return atomic_read(&vmstats->stats_updates) > + return atomic_long_read(&vmstats->stats_updates) > MEMCG_CHARGE_BATCH * num_online_cpus(); } =20 -static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val, +static inline void memcg_rstat_updated(struct mem_cgroup *memcg, long val, int cpu) { struct memcg_vmstats_percpu __percpu *statc_pcpu; struct memcg_vmstats_percpu *statc; - unsigned int stats_updates; + unsigned long stats_updates; =20 if (!val) return; @@ -697,7 +697,7 @@ static inline void memcg_rstat_updated(struct mem_cgrou= p *memcg, int val, continue; =20 stats_updates =3D this_cpu_xchg(statc_pcpu->stats_updates, 0); - atomic_add(stats_updates, &statc->vmstats->stats_updates); + atomic_long_add(stats_updates, &statc->vmstats->stats_updates); } } =20 @@ -705,7 +705,7 @@ static void __mem_cgroup_flush_stats(struct mem_cgroup = *memcg, bool force) { bool needs_flush =3D memcg_vmstats_needs_flush(memcg->vmstats); =20 - trace_memcg_flush_stats(memcg, atomic_read(&memcg->vmstats->stats_updates= ), + trace_memcg_flush_stats(memcg, atomic_long_read(&memcg->vmstats->stats_up= dates), force, needs_flush); =20 if (!force && !needs_flush) @@ -4446,8 +4446,8 @@ static void mem_cgroup_css_rstat_flush(struct cgroup_= subsys_state *css, int cpu) } WRITE_ONCE(statc->stats_updates, 0); /* We are in a per-cpu loop here, only do the atomic write once */ - if (atomic_read(&memcg->vmstats->stats_updates)) - atomic_set(&memcg->vmstats->stats_updates, 0); + if (atomic_long_read(&memcg->vmstats->stats_updates)) + atomic_long_set(&memcg->vmstats->stats_updates, 0); } =20 static void mem_cgroup_fork(struct task_struct *task) --=20 2.20.1