WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] scheduler independent forced vcpu selection

To: Stephan Diestelhorst <sd386@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] scheduler independent forced vcpu selection
From: Ryan Harper <ryanh@xxxxxxxxxx>
Date: Wed, 18 May 2005 17:37:44 -0500
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 18 May 2005 22:39:15 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <428B30BC.8070602@xxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <20050517204832.GH7305@xxxxxxxxxx> <428B30BC.8070602@xxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.6+20040907i
* Stephan Diestelhorst <sd386@xxxxxxxxxxxx> [2005-05-18 09:04]:
> > I'm working on a new hypercall, do_confer, which allows the directed
> > yielding of a vcpu to another vcpu.  It is mainly used when a vcpu fails
> > to acquire a spinlock, yielding to the lock holder instead of spinning. I
> > ported the ppc64 spinlock implementation for the i386 linux portion.  In
> > implementing the hypercall, I've been trying to figure out how to get
> > the scheduler (I've only played with bvt) to run the vcpu passed in the
> > hypercall (after some validation) but I've run into various bad state
> > situations (do_softirq pending != 0 assert, '!active_ac_timer(timer)'
> > failed , and __task_on_runqueue(prev) failed) which tells me I
> > don't fully understand all of the book-keeping that is needed.  Has
> > anyone thought about how to do this with either BVT or the new EDF
> > scheduler?

After some thought, domain_wake(), followed by
raise_softirq(SCHEDULE_SOFTIRQ) does what I want and removes the huge
mess I was making in __enter_scheduler().  

-- 
Ryan Harper
Software Engineer; Linux Technology Center
IBM Corp., Austin, Tx
(512) 838-9253   T/L: 678-9253
ryanh@xxxxxxxxxx

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel