From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ryan Harper Subject: Re: scheduler independent forced vcpu selection Date: Wed, 18 May 2005 17:37:44 -0500 Message-ID: <20050518223744.GL7305@us.ibm.com> References: <20050517204832.GH7305@us.ibm.com> <428B30BC.8070602@cl.cam.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <428B30BC.8070602@cl.cam.ac.uk> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Stephan Diestelhorst Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org * Stephan Diestelhorst [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@us.ibm.com