Re: [PATCH v2] core, x86: Add user return notifiers

[Avi Kivity]

On 09/22/2009 12:37 PM, Arjan van de Ven wrote:
> On Tue, 22 Sep 2009 12:25:33 +0300
> Avi Kivity<avi@xxxxxxxxxx>  wrote:
>
>    
> > On 09/19/2009 09:40 AM, Avi Kivity wrote:
> >      
> > > Add a general per-cpu notifier that is called whenever the kernel is
> > > about to return to userspace.  The notifier uses a thread_info flag
> > > and existing checks, so there is no impact on user return or context
> > > switch fast paths.
> > >
> > >        
> > Ingo/Peter?
> >      
> isn't this like really expensive when used ?
>    

No, why?  It triggers a call to do_notify_resume() and a walks a list of 
length 1.

--
error compiling committee.c: too many arguments to function

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