From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] virtio-net: fix a race on 32bit arches Date: Sun, 10 Jun 2012 20:23:41 -0700 (PDT) Message-ID: <20120610.202341.2146277133562218686.davem@davemloft.net> References: <1338971724.2760.3913.camel@edumazet-glaptop> <20120610102512.GB6793@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120610102512.GB6793@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: mst@redhat.com Cc: eric.dumazet@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, shemminger@vyatta.com List-Id: virtualization@lists.linuxfoundation.org From: "Michael S. Tsirkin" Date: Sun, 10 Jun 2012 13:25:12 +0300 > On Wed, Jun 06, 2012 at 10:35:24AM +0200, Eric Dumazet wrote: >> From: Eric Dumazet >> >> commit 3fa2a1df909 (virtio-net: per cpu 64 bit stats (v2)) added a race >> on 32bit arches. >> >> We must use separate syncp for rx and tx path as they can be run at the >> same time on different cpus. Thus one sequence increment can be lost and >> readers spin forever. >> >> Signed-off-by: Eric Dumazet >> Cc: Stephen Hemminger >> Cc: Michael S. Tsirkin >> Cc: Jason Wang > > I'm still thinking about moving tx to take a xmit lock long term, > meanwhile this fix appears appropriate for 3.5. > > Acked-by: Michael S. Tsirkin > > Dave, can you pick this up pls? Done, thanks.