From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120528031213.511349348@decadent.org.uk> Date: Mon, 28 May 2012 04:13:19 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Sha Zhengju , KAMEZAWA Hiroyuki , "Kirill A. Shutemov" Subject: [ 077/117] memcg: free spare array to avoid memory leak In-Reply-To: <20120528031202.829379252@decadent.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sha Zhengju commit 8c7577637ca31385e92769a77e2ab5b428e8b99c upstream. When the last event is unregistered, there is no need to keep the spare array anymore. So free it to avoid memory leak. Signed-off-by: Sha Zhengju Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Kirill A. Shutemov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- mm/memcontrol.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 31ab9c3..b659260 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4507,6 +4507,12 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp, swap_buffers: /* Swap primary and spare array */ thresholds->spare = thresholds->primary; + /* If all events are unregistered, free the spare array */ + if (!new) { + kfree(thresholds->spare); + thresholds->spare = NULL; + } + rcu_assign_pointer(thresholds->primary, new); /* To be sure that nobody uses thresholds */