From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: context switch Date: Wed, 29 Mar 2006 10:06:46 +0100 Message-ID: <1ae2e58ee99fc978bcf549cbea2b040d@cl.cam.ac.uk> References: <44284B8E.E57C.0030.0@novell.com> <44291E76.E57C.0030.0@novell.com> <44292D32.E57C.0030.0@novell.com> <094de57bd0b22d011e9ecef9b84677a8@cl.cam.ac.uk> <8faa95f64ad61af657bdda6b115b5fd4@cl.cam.ac.uk> <44299342.E57C.0030.0@novell.com> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <44299342.E57C.0030.0@novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Ky Srinivasan Cc: xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org On 29 Mar 2006, at 01:49, Ky Srinivasan wrote: > What are your thoughts on having a mechanism to manage hypervisor > preemption from guest kernels? Potentially a scheduler activations interface would be nice for SMP guests, if it's not too hard to modify the OS to support it. I don't see how a preemption aware interface would improve prepare_arch_switch() though -- I already said that failsafe_handler() should pick up the slack if you remove selector zeroing from prepare_arch_switch(). You may get some noise from Xen on a debug build, but things should carry on working just fine. If I'm missing your point, you need to give some more details about what you're proposing. :-) -- Keir