From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Limpach Subject: Re: /proc/xen/xenbus supports watch? Date: Tue, 13 Sep 2005 10:42:44 +0100 Message-ID: <3d8eece205091302422ac74f77@mail.gmail.com> References: <5d7aca9505090801025f3d5771@mail.gmail.com> <3d8eece205090803381b818f18@mail.gmail.com> <1126226609.25110.3.camel@localhost.localdomain> Reply-To: Christian.Limpach@cl.cam.ac.uk Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1126226609.25110.3.camel@localhost.localdomain> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Rusty Russell Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 9/9/05, Rusty Russell wrote: > On Thu, 2005-09-08 at 11:38 +0100, Christian Limpach wrote: > > On 9/8/05, NAHieu wrote: > > > Anybody (Christian?) could please tell me if we can get the support > > > for registering watch with /proc/xen/xenbus? (..OK, I know that we > > > will change it this /proc stuff to a device soon) > > > > > > So far we can only do read/write/rm. I really miss the xen watch feat= ure. >=20 > At the moment, the xenbus device is a simple hack which grabs the lock > on all store communication on open, and drops it on close. It's not > really a general mechanism for tools in domUs to communicate with the > store. Could we reduce the time we hold the lock to from before we call xb_write until both data->bytes_left and data->awaiting_reply are 0 again? I think this would work except for transactions, how do you feel about supporting multiple transactions per connection? Should we at least extend the interface now so that we can add concurrent transaction support later, i.e. transaction start returning a handle and all operations taking a handle argument? christian