From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] Fix guest memory leak and panic Date: Tue, 18 Oct 2011 15:12:28 -0400 (EDT) Message-ID: <20111018.151228.2056792649526003804.davem@davemloft.net> References: <20111018080523.16861.55402.sendpatchset@krkumar2.in.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: rusty@rustcorp.com.au, mst@redhat.com, Ian.Campbell@citrix.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org To: krkumar2@in.ibm.com Return-path: In-Reply-To: <20111018080523.16861.55402.sendpatchset@krkumar2.in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Krishna Kumar Date: Tue, 18 Oct 2011 13:35:23 +0530 > Commit 86ee8130 ("virtionet: convert to SKB paged frag API") > introduced a bug in guest. During RX testing, guest runs out > of memory within seconds, causing oom-killer; which then > panics the system: "Kernel panic - not syncing: Out of memory > and no killable processes...". /proc/meminfo just before the > panic shows MemFree is a few MB's: > > MemFree: 1928544 kB (starts here) > ... > ... > MemFree: 27488 kB > MemFree: 26248 kB > MemFree: 24636 kB > MemFree: 22632 kB > MemFree: 19580 kB > MemFree: 17928 kB > MemFree: 15548 kB > (Panic) > > The extra reference to the fragment pages causes those pages to > not get freed in skb_release_data(). The following patch fixes > the bug. I have not checked if any other converted driver has > the same issue. > > Signed-off-by: Krishna Kumar I'll wait for Ian's full audit, but Krishna please use more appropriate subject lines in future patch submissions. This patch is fixing a problem in the virtio_net driver, so please mention that: "Subject: [PATCH] virtio_net: Fix guest memory leak and panic"