From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Durrant Subject: Re: [PATCH] VNIF: Using smart polling instead of event notification. Date: Thu, 1 Oct 2009 15:21:10 +0100 Message-ID: <4AC4BAD6.8070804@citrix.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "Xu, Dongxiao" Cc: Ian Campbell , "xen-devel@lists.xensource.com" , Keir Fraser List-Id: xen-devel@lists.xenproject.org Xu, Dongxiao wrote: > We found that the event notification frequency is still high in some network cases. NAPI polls only for a little > time slot and does not efficient enough in our backend/frontend case. Actually our patch repeated calling NAPI > interface to do more polling, and netback will NOT notify netfront during this period. Once netfront polling out > all the data, and finds that there is no more data arrive/send during the next 100ms, the timer will stop working > to end the polling. > This filed 'smart_poll_active' is shared by netfront and netback, to indicate whether netfront is polling data. > So this filed is necessary for netback to notify netfront if this flag is not set. > This field is different from the flag in xenstore, which indicates whether other-end has this new feature. If other-end doesn't support the new feature, everything goes in the original way. > If you want to prevent event notification, why not simply mask out your port? Paul