From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH RFC] xenbus_client: extend interface to suppurt multi-page ring Date: Tue, 20 Aug 2013 13:11:58 -0400 Message-ID: <20130820171158.GE11652@phenom.dumpdata.com> References: <1369922760-11800-1-git-send-email-wei.liu2@citrix.com> <20130530140912.GI4394@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20130530140912.GI4394@zion.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu , david.vrabel@citrix.com, boris.ostrovsky@oracle.com Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Thu, May 30, 2013 at 03:09:12PM +0100, Wei Liu wrote: > On Thu, May 30, 2013 at 03:06:00PM +0100, Wei Liu wrote: > > Originally Xen PV drivers only use single-page ring to pass along > > information. This might limit the throughput between frontend and > > backend as they can easily run out of ring slots if hardware is fast. > > > > The patch extends Xenbus driver to support multi-page ring, which in > > general should improve throughput. Changes to various frontend / backend > > to adapt to the new interface are also included. > > > > Affected Xen drivers: > > * blkfront/back > > * netfront/back > > * pcifront/back > > > > The interface is documented, as before, in xenbus_client.c. > > > > Please note that this patch won't apply cleanly on upstream kernel as it > relies on some patches that are not in tree. OK. > > I mainly want to collect views on the interface. Also in the HVM case I > use vmap, I would like to know if I get it right. This patches looks familiar that I had seen some time ago (maybe I even backported it for PV?). Anyhow the PV part looks OK. The HVM - I don't see why we cannot do vmap. The nature of the ring is that it stays mapped for a very long time - so using vmap is OK. That is, the issues with vmap is that it takes a bit to setup and teardown - and that is OK with us. If you would like to rebase it on top of v3.11-rc5 and repost it I don't see why we can't have it for v3.12. David, Boris? > > > Thanks > Wei. > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel >