From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yuanhan Liu Subject: Re: [PATCH] vhost: remove lockless enqueue to the virtio ring Date: Wed, 16 Mar 2016 16:30:04 +0800 Message-ID: <20160316083004.GQ979@yliu-dev.sh.intel.com> References: <1451918787-85887-1-git-send-email-huawei.xie@intel.com> <13376800.Cqouxc5gkz@xps13> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Thomas Monjalon , "dev@dpdk.org" , "ann.zhuangyanying@huawei.com" To: "Xie, Huawei" Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 021102BFA for ; Wed, 16 Mar 2016 09:29:04 +0100 (CET) Content-Disposition: inline In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Wed, Mar 16, 2016 at 08:20:37AM +0000, Xie, Huawei wrote: > On 3/15/2016 7:14 AM, Thomas Monjalon wrote: > > 2016-01-05 07:16, Xie, Huawei: > >> On 1/5/2016 2:42 PM, Xie, Huawei wrote: > >>> This patch removes the internal lockless enqueue implmentation. > >>> DPDK doesn't support receiving/transmitting packets from/to the same > >>> queue. Vhost PMD wraps vhost device as normal DPDK port. DPDK > >>> applications normally have their own lock implmentation when enqueue > >>> packets to the same queue of a port. > >>> > >>> The atomic cmpset is a costly operation. This patch should help > >>> performance a bit. > >>> > >>> Signed-off-by: Huawei Xie > >> This patch modifies the API's behavior, which is also a trivial ABI > >> change. In my opinion, application shouldn't rely on previous behavior. > >> Anyway, i am checking how to declare the ABI change. > > I guess this patch is now obsolete? > > How about we delay this to next release after more considerations, I'd suggest so. > whether we should keep this behavior, and what is the best way for > concurrency in vhost. I'm wondering should we do an announcement first, to notify user the behaviour change? --yliu