From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ky Srinivasan" Subject: Re: vcpu_pause Date: Sun, 04 Mar 2007 16:02:37 -0700 Message-ID: <45EAF9DA.E57C.0030.0@novell.com> References: <45E85C62.E57C.0030.0@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Keir Fraser , xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Kier, Sorry for not being precise in my earlier email. Within an arbitrary domain, I was wondering how we were preventing potential deadlocks between vcpus that were attempting to pause each other; perhaps a higher level serialization lock could solve this problem. I was looking at using vcpu_pause to get a stable state for a vcpu in a domu context. Is this not a sanctioned usage of vcpu_pause. K. Y >>> On Sun, Mar 4, 2007 at 6:56 AM, in message , Keir Fraser wrote: > Synchronous vcpu_pause() and domain_pause() are only used on paths > executable in dom0 context. Hence there is no loop in the graph of > domain- X- can- pause- domain- Y, and we'll need to maintain that asymmetry when > we disaggregate dom0. For now, a BUG_ON(current- >domain != dom0) in > vcpu_sleep_sync() would probably make things clearer. > > -- Keir > > On 2/3/07 23:26, "Ky Srinivasan" wrote: > >> What are the expected entry conditions to call vcpu_pause. How do we > guarantee >> two vcpus don't deadlock by calling pause on each other. >> >> Regards, >> >> K. Y >> >> >> >> _______________________________________________ >> Xen- devel mailing list >> Xen- devel@lists.xensource.com >> http://lists.xensource.com/xen- devel