help with sandybridge/ivybridge hwpmc NUMA DRAM counters

Adrian Chadd adrian at freebsd.org
Thu Apr 23 06:38:23 UTC 2015


hi all,

I'm having a spot of problem trying to get the local/remote dram
counters working on the NUMA sandybridge and ivybridge systems here.

Things work fine using intel-pcm, but those same counters don't work with hwpmc.

Sandybridge - there's apparently an MSR that needs to be fiddled if
the counters are active.

Ivybridge - the v1 and v2 chips have different local/remote dram
counters, and on my v2 setup there's actually /two/ LOCAL_DRAM:

adrian at testbox1:~/git/github/erikarn/freebsd/sys/dev/hwpmc %
pmccontrol -L | grep DRAM
        MEM_LOAD_UOPS_LLC_MISS_RETIRED.LOCAL_DRAM
        MEM_LOAD_UOPS_LLC_MISS_RETIRED.LOCAL_DRAM
        MEM_LOAD_UOPS_LLC_MISS_RETIRED.REMOTE_DRAM

Now, i may be able to get to figuring this out at some point in the
distant future, but I'd really appreciate any help I can get now. I'm
now at the point with the NUMA affinity API stuff where I'm now
chasing down when things are correctly working with local/remote RAM,
and I'd really like to use hwpmc in sampling mode to work on it.

Thanks for any help!



-adrian


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