lkml.org 
[lkml]   [2012]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] KVM: VMX: add tracepoint for vpids
On Mon, 2012-03-12 at 12:34 +0200, Avi Kivity wrote:
> On 03/12/2012 01:29 PM, Davidlohr Bueso wrote:
> > On Mon, 2012-03-12 at 10:22 +0200, Avi Kivity wrote:
> > > On 03/11/2012 05:57 PM, Davidlohr Bueso wrote:
> > > > From: Davidlohr Bueso <dave@gnu.org>
> > > >
> > > > Add a new tracepoint for vpid allocation and freeing associated to all vCPUs.
> > > >
> > >
> > > Why?
> > >
> >
> > We have been using this tracepoint for some time now to help debug vpids
> > and simulating tagged TLB behavior and performance. This gets to be non
> > trivial when working with large amounts of guests and vCPUs.
>
> I don't follow. Can you give an example of when this tracepoint would
> be useful?
>

For example when running lots of guests with many different hardware
configurations (ept on/off, vpid on/off) I trace what vcpu has or
doesn't have a corresponding vpid associated. Perhaps this is more
useful for experimental things than actual KVM development.





\
 
 \ /
  Last update: 2012-03-13 10:59    [from the cache]
©2003-2011 Jasper Spaans