From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 1513B1CFBA for ; Sat, 6 Sep 2025 14:13:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757168004; cv=none; b=Be+/LOibRIw6TUQxBy8/m5c3aNbDkz9Vg7HCI0mXbAO9yyv7R68ecprKwNtvzT3yOL8N/ARy51rtBAz4lf4U5YQ+Js558jLfI/PVp974by4fV00igOp/Xd8PHu4IKTu1nR2nRZf/XNcmD/Zypq1KipGzxZqvZBXoV8EnaedHwbo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757168004; c=relaxed/simple; bh=ZV3vqEnM0WAi4bjJLZPzUz7OIaGMBCuljYkxOjETmwI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=b8NcU5KKRWjdxq3BbilnmXhWa7/c1HdHIH5SYKwgpHr8L45QJr6vOeAkLYWt8G/EgIB2ZMW8tb1JZ30CAFUWsFq98NZggi9E2EvETO0S+j015Yrvsjl3T+haEyzCNjnUz75ScYcWtN6U74Ubc+o0O06LrThIYMUHnVqWiT7EDPo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uwdKOZjf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="uwdKOZjf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C20A7C4CEF5; Sat, 6 Sep 2025 14:13:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757168003; bh=ZV3vqEnM0WAi4bjJLZPzUz7OIaGMBCuljYkxOjETmwI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uwdKOZjfDR2I4qOC7N7TcjwJMwuRnGVfavFsG2vsC1lXApkBqdikqzLCkotBdPs09 FxzXHtTVlIQpJewbq5fgbx2AOu6jmVaFvikv0G4YRfSLFvlYUsSlH2X0iB2AQnUTj+ W/Uw/x8LnsIe/riFjiSKE3ru6tpH0KF1pQ95JdTAwkcrLqFfnoaWAAgA/OJ2i7yyCs MIMplp679qnoxkAwHj7A7Kh6V0STL8AOyUwGOuBf09v3mXTcXNy+F4he68D4BozsbL b1nSC7oHP6Y07aZxJDSkWp+0OEhNq/1Zb1V2jmkxm0VoLdBjAUEeuHY0Y7yxNOzkiK m3a4PKnE455GQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Shakeel Butt , Roman Gushchin , Johannes Weiner , Michal Hocko , Muchun Song , Andrew Morton , Sasha Levin Subject: [PATCH 6.1.y] memcg: drain obj stock on cpu hotplug teardown Date: Sat, 6 Sep 2025 10:13:21 -0400 Message-ID: <20250906141321.25877-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025032807-famished-reprocess-abd3@gregkh> References: <2025032807-famished-reprocess-abd3@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Shakeel Butt [ Upstream commit 9f01b4954490d4ccdbcc2b9be34a9921ceee9cbb ] Currently on cpu hotplug teardown, only memcg stock is drained but we need to drain the obj stock as well otherwise we will miss the stats accumulated on the target cpu as well as the nr_bytes cached. The stats include MEMCG_KMEM, NR_SLAB_RECLAIMABLE_B & NR_SLAB_UNRECLAIMABLE_B. In addition we are leaking reference to struct obj_cgroup object. Link: https://lkml.kernel.org/r/20250310230934.2913113-1-shakeel.butt@linux.dev Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") Signed-off-by: Shakeel Butt Reviewed-by: Roman Gushchin Acked-by: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 420efa1d2b203..8938013358997 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2366,9 +2366,18 @@ static void drain_all_stock(struct mem_cgroup *root_memcg) static int memcg_hotplug_cpu_dead(unsigned int cpu) { struct memcg_stock_pcp *stock; + struct obj_cgroup *old; + unsigned long flags; stock = &per_cpu(memcg_stock, cpu); + + /* drain_obj_stock requires stock_lock */ + local_lock_irqsave(&memcg_stock.stock_lock, flags); + old = drain_obj_stock(stock); + local_unlock_irqrestore(&memcg_stock.stock_lock, flags); + drain_stock(stock); + obj_cgroup_put(old); return 0; } -- 2.51.0