From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zoltan Kiss Subject: Re: [PATCH net v4 0/3] xen-netback: synchronisation between core driver and netback Date: Tue, 12 Aug 2014 17:53:46 +0100 Message-ID: <53EA469A.5030008@citrix.com> References: <1407840488-20026-1-git-send-email-wei.liu2@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: , To: Wei Liu , , Return-path: Received: from smtp.citrix.com ([66.165.176.89]:24056 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752981AbaHLQxu (ORCPT ); Tue, 12 Aug 2014 12:53:50 -0400 In-Reply-To: <1407840488-20026-1-git-send-email-wei.liu2@citrix.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/08/14 11:48, Wei Liu wrote: > The zero-copy netback has far more interactions with core network driver than > the old copying backend. One significant thing is that netback now relies on > a callback from core driver to correctly release resources. > > However correct synchronisation between core driver and netback is missing. > Currently netback relies on a loop to wait for core driver to release > resources. This is proven not enough and erroneous recently, partly due to code > structure, partly due to missing synchronisation. Short-live domains like > OpenMirage unikernels can easily trigger race in backend, rendering backend > unresponsive. > > This patch series aims to slove this issue by introducing proper > synchronisation between core driver and netback. > > Wei. > > Chagges in v4: > * avoid using wait queue > * remove dedicated loop for netif_napi_del > * remove unnecessary check on callback > > Change in v3: improve commit message in patch 1 > > Change in v2: fix Zoltan's email address in commit message > > > Wei Liu (3): > xen-netback: move NAPI add/remove calls > xen-netback: don't stop dealloc kthread too early > xen-netback: remove loop waiting function > > drivers/net/xen-netback/common.h | 5 ++++ > drivers/net/xen-netback/interface.c | 56 ++++++++++++++--------------------- > drivers/net/xen-netback/netback.c | 26 +++++++++++----- > 3 files changed, 47 insertions(+), 40 deletions(-) > Looks good for me. Acked-by: Zoltan Kiss