Re: disabling group leader perf_event

[Ingo Molnar <mingo@elte.hu>]

* Avi Kivity <avi@redhat.com> wrote:

>  On 09/06/2010 03:43 PM, Ingo Molnar wrote:
> >
> > Yes. The filter engine is a safe, in-kernel interpreted language in 
> > the making. The C syntax was chosen because it's close to the heart 
> > of every kernel developer.
> >
> > It might make sense to bring this concept a few steps further. Looks 
> > rather complex but also rather cool ...
> 
> Is this a roundabout way of saying "jit"?

Partly. I'm not sure we want to actually upload programs in bytecode 
form. ASCII is just fine - just like a .gz Javascript is fine for web 
apps. (and in most cases compresses down better than the bytecode 
equivalent)

So a clear language (the simpler initially the better) plus an in-kernel 
compiler.

This could be used for far more than just instrumentation: IMO security 
policies could be expressed in such a way. (Simplified, they are quite 
similar to filters installed on syscall entry/exit, with the ability of 
the filter to influence whether the syscall is performed.)

> If so, I'm all for it.  I could use one myself.

Good ;-)

Thanks,

	Ingo