* Oleg Nesterov <o...@redhat.com> [2013-01-24 18:06:12]: > On 01/24, Ingo Molnar wrote: > > > > * Oleg Nesterov <o...@redhat.com> wrote: > > > > > 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. > > Heh, I understand. > > I do not see anything simple to implement... I'll try to think. > Srikar, do you have any idea? > > All I can say right now: I'll send you the patches when I have them ;) > Can't promise this will be soon. > > _Perhaps_, as a first step, we can simply change create_trace_uprobe() > so that it would be possible to specify list-of-pids at creation time... > Not sure this actually makes sense. >
[ Adding Masami and Steven since they have other ideas / inputs ] I can see two not-so-easy alternatives Reuse the event's post filtering meta data and convert it to a prefiltering handler. Convertion looks very tricky probe_event_enable() seems to be the right place to do this. tu->call.filter would have the post filtering data utc->filter needs to be set to the pre-filtering handler. The other alternative is to extend the current abi and pass the prefilter option. Should we extend the abi for userspace tracing is obviously debatable. > Oleg. > -- Thanks and Regards Srikar Dronamraju -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
