lkml.org 
[lkml]   [2010]   [Apr]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: VM performance issue in KVM guests.
On Thu, Apr 15, 2010 at 03:33:18PM +0200, Peter Zijlstra wrote:
> On Thu, 2010-04-15 at 11:18 +0300, Avi Kivity wrote:
> >
> > Certainly that has even greater potential for Linux guests. Note that
> > we spin on mutexes now, so we need to prevent preemption while the lock
> > owner is running.
>
> either that, or disable spinning on (para) virt kernels. Para virt
> kernels could possibly extend the thing by also checking to see if the
> owner's vcpu is running.

I suspect we will need a combination of both approaches, given that we will not
be able to avoid preempting guests in their critical section always (too long
critical sections or real-time tasks wanting to preempt). Other idea is to
gang-schedule VCPUs of the same guest as much as possible?

- vatsa


\
 
 \ /
  Last update: 2010-04-15 18:47    [W:0.661 / U:0.188 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site