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 59BA114BFA2; Sun, 7 Sep 2025 20:18:14 +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=1757276294; cv=none; b=TCIYW+K8OgRZ8Z8G2WqLHDC1s4EwJs9tIHifDYwKFezBGJTleKh3FcPUr3O98TBH5m8rPQLO77zWv1eE0Cl5Lpkyj50VJieCIf/RmZfvD3fZPGely4gs1LSN1LtXPiDdJD8v5grOtrd60sG6hOFXHVYHs6NyfqNuK3VI4ulQ+Pk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757276294; c=relaxed/simple; bh=4/8huJ41Gzu6uSafmiwZVKNTsoKtMvusfF4HoTywOe0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=d2gnAbH36YtKREHvXvDaGtlxzyrju09mhyo6GpxDYZx6ZUrxy4BL2QTmlmLtkDMzEoYx9aJc9isj77jW0mZzGkpWW5wvMBlwQxN8+qIbrKB+TRPfFYhQ0FIhYrnD6WgeaTIXKqzR3ZbW6mzx0gF/dYvekbB6ArF1/nPmXRReNDM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xirzJ5js; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xirzJ5js" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFAA6C4CEF0; Sun, 7 Sep 2025 20:18:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757276294; bh=4/8huJ41Gzu6uSafmiwZVKNTsoKtMvusfF4HoTywOe0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xirzJ5jsGX2kRBuZDo0Xl+3bTjwT79JL3O5fJoRRHle+iMUWrAJrHOI86ncS4Cgs3 XPpQ51IBxgE2hxl4mMgdtCOD90/kserffoQZ3/2RA2cJ3HThkqfdYqQ3LZ5LLwwS2w nkChnCsfRrCr7J0Hdsogk8J/M94qbeEwSTO2wWfA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shakeel Butt , Roman Gushchin , Johannes Weiner , Michal Hocko , Muchun Song , Andrew Morton , Sasha Levin Subject: [PATCH 6.1 057/104] memcg: drain obj stock on cpu hotplug teardown Date: Sun, 7 Sep 2025 21:58:14 +0200 Message-ID: <20250907195609.161338429@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195607.664912704@linuxfoundation.org> References: <20250907195607.664912704@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- mm/memcontrol.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2366,9 +2366,18 @@ static void drain_all_stock(struct mem_c 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; }