Re: [GIT PULL] uprobes: pre-filtering

[Oleg Nesterov <oleg@redhat.com>]

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.

Oleg.