From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: Scalable Event Channel ABI design (draft A) Date: Wed, 06 Feb 2013 13:53:12 +0000 Message-ID: References: <51123F59.6030901@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <51123F59.6030901@eu.citrix.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: George Dunlap , David Vrabel Cc: Wei Liu , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org On 06/02/2013 11:32, "George Dunlap" wrote: >> 4. Get the 3-level ABI to a mergable state. In parallel develop a >> prototype of the FIFO-based ABI. When the prototype is ready or the 4.3 >> freeze is here, evaluate it and make a decision then. > > Just to clarify, the difference between #1 and #4 is that in #4 we hold > off on the merge, to delay committing to a specific course of action > until later? > > That seems at first blush to be a pretty safe option. But I think it's > worth pointing out that in practice the end result is likely to be that > we just go with #1 eventually anyway: if the FIFO ABI can't be finished > in 4 months giving it all our effort, can we really expect it to be > finished in any less time while polishing up the 3-level ABI? > > I was going to say, "There's no particular reason to merge the 3-level > ABI sooner rather than later", but of course there is: it allows > considerably longer and wider testing. > > No conclusion here, just adding to the mix of things to consider. :-) How many man-weeks do we think David's design would take to get to draft implementation? I mean honestly I would have thought that a straight two-week run at it would be a reasonable estimate -- the places it plugs in in hypervisor and guest kernel are pretty clean and well defined. This depends on a man having the weeks to spend on it of course! -- Keir