Hey folks,
With the release going out earlier today I just wanted to demo a bit of
the PAPI pmda functionality.
The pmda features a host of papi.control metrics used for
enabling/disabling counters and administration of the pmda. The metrics
themselves are papi.METRIC, where METRIC is the suffix of the PAPI event
code (ie, PAPI_TOT_INS becomes TOT_INS). Currently the metrics are
system wide, with process/thread specific metrics (hopefully) coming
soon.
If I wanted to compare the number of system wide Level 1 Total Cache
Misses to Level 1 Total Cache Hits I would;
sudo pmstore papi.control.enable "L1_TCM L1_TCH" (enable/disable being a
space or ',' sperated list)
sudo pmval papi.T1_TCH (view subsequent output)
sudo pmval papi.T1_TCM (view more output)
sudo pmstore papi.control.disable "L1_TCM,L1_TCH"
Considering the limited number of counters available may change based on
the architecture, the papi.control.num_counters metric has also been
added to compare against when possibly writing pmie expressions.
A few other TODO's I have lined up for the pmda: I'd like to eventually
make the enable/disable control metrics a bit more flexible (ie, pmstore
papi.control.disable "*" or "all" would be nice). We're also working
around a papi issue where currently, after adding another metric or
removing, the counters reset, which we should account for the user (if
possible). There is also the point of making the pmns more dynamic,
based on the current hardware, and if we can avoid needing to use the
papi.control.{enable,disable} metrics. (and of course, more qa as
needed)
If you have time and want to try out the pmda, please let me know if you
have any comments on it, I'd appreciate any kind of feedback!
Cheers,
Lukas
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