Hi, On Tue, Jun 24, 2014 at 7:36 PM, Luís Taniça <[email protected]> wrote: > Hi, > > I am trying to configure 8 events in a machine which supports only 4 (so, > using multiplexing). I tried different approaches: > > 1) Configure 8 events independently (works as expected) > 2) Configure 2 event-sets of 4 events each in counting mode (works as > expected) > 3) Configure 2 event-sets of 4 events each in sampling mode (not > working right) > What do it mean 'not working' in 3)? Are you using perf record or your own code?
I think it would help if you could share the exact setup, i.e., the various struct perf_event_attr structs. > In case 3) I also tried different approaches: > > 3.a) 1 ring-buffer for each event-set and a callback for the POLL > signal > - only the first ring-buffer was detecting samples > - the second ring-buffer was empty > > 3.b) 1 ring-buffer shared between event-sets (using > PERF_EVENT_IOC_SET_OUTPUT) > - both event-sets were writing to the ring-buffer > - 1st event-set only writes 2 samples while 2nd event-set > writes like 20+ samples > - samples from 1st event-set report time_enabled=time_running > while samples from 2nd don’t > > Moreover, in both cases the wakeup_events parameter is not working. > I believe there must be some programming bugs in perf_event while profiling > in sampling mode with multiple event-sets (groups). > > Regards, > matallui > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
