From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rusty Russell Subject: Re: [Xen-devel] Re: [PATCH RFC 0/3] Virtio draft III Date: Mon, 18 Jun 2007 17:48:01 +1000 Message-ID: <1182152881.19064.9.camel@localhost.localdomain> References: <1181217762.14054.192.camel@localhost.localdomain> <1181999552.6237.255.camel@localhost.localdomain> <467541DF.5060907@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Stephen Rothwell , Xen Mailing List , "jmk-zzFmDc4TPjtKvsKVC3L/VUEOCMrvLtNR@public.gmane.org" , Herbert Xu , kvm-devel , virtualization , Christian Borntraeger , Latchesar Ionkov , Suzanne McIntosh , Martin Schwidefsky To: Avi Kivity Return-path: In-Reply-To: <467541DF.5060907-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Sun, 2007-06-17 at 17:14 +0300, Avi Kivity wrote: > Rusty Russell wrote: > > In this episode, Rusty tries to NAPI-ize the driver and discovers that > > virtio callbacks are a bad idea: NAPI needs to turn interrupts off and > > still be able to query for new incoming packets. > > > > Changes to core: > > 1) Back to "interrupt" model with get_inbuf()/get_outbuf() calls. > > > > Seems to be these are just two different ways of iterating over the > pending buffers, and one could be implemented in terms of the other in a > few lines. I think that new new way is better, though, due to less > indirection. Yes, the lguest implementation points them to a common routine. We could do some batching here too, but it seemed like premature optimization. > btw, I'm not sure that the name 'virtio' is correct. Probably any > network or block driver which has support for batching (the vast > majority) could use this to good effect. Trying to avoid boiling the ocean 8) Cheers, Rusty. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/