Re: [RFC][PATCH 3/9] perf: export registerred pmus via sysfs

[Peter Zijlstra]

On Tue, 2010-05-11 at 16:20 +0800, Lin Ming wrote:

> How will this sysfs interface be used for userspace tool?
> 
>  /sys/devices/system/node/nodeN/node_events
>                                node_events/event_source_id
> 
>                                node_events/local_misses/event_id
>                                           /local_hits/event_id
>                                           /remote_misses/event_id
>                                           /remote_hits/event_id
> 
> For example, to monitor node event local_misses on node 0, does it work
> as below?
> 
> 1. perf top -e local_misses -n 0 (-n 0 means node 0)
> 
> 2. read /sys/devices/system/node/node0/node_events/event_source_id to
> get the pmu_id
> 
> 3. read /sys/devices/system/node/node0/node_events/local_misses/event_id
> to get the event_id
> 
> 4. event_attr::pmu_id=pmu_id, event::config=event_id
> 
> 5. other setting...
> 
> 6. call syscall perf_event_open(....)

No, you'll use event_source_id as perf_event_attr::type, use event_id as
perf_event_attr::config and then use a cpu-wide counter on a cpu
contained in node0.


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/