Re: [GIT PULL] uprobes: pre-filtering

[Ingo Molnar <mingo@kernel.org>]

* Oleg Nesterov <oleg@redhat.com> wrote:

> On 01/24, Ingo Molnar wrote:
> >
> > * Oleg Nesterov <oleg@redhat.com> wrote:
> >
> > > Ingo, please pull from
> > >
> > >   git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc uprobes/core
> > >
> > > Mostly pre-filtering. This needs more work and perhaps more functionality.
> > > In particular, perhaps dup_mmap() should remove the unwanted breakpoints.
> > > And we can add more ->filter() hooks to, say, speedup uprobe_register().
> > > Plus we can do some optimizations to avoid register_for_each_vma() in
> > > case when we know that all mm's were previously acked/nacked.
> >
> > The kernel side looks good to me - but how does 'perf 
> > uprobe' make use of it in practice, how can I test it?
> 
> Unfortunately, currently there is no in-kernel user of 
> pre-filtering.
> 
> I'll try to implement the pid-base filtering at least for 
> tracing/uprobe_events, but this needs a time. Not only I am 
> not familiar with this code, I am not sure how this interface 
> should actually look. And I agree, perf should be able to use 
> it somehow, perhaps at least to allow to probe a single 
> task/mm.

Would be nice to get something minimal/simple going, so that it 
can be tested, etc.

Thanks,

	Ingo