[RFC/BUG] not working LLC-load-misses on SandyBridge (42) and Haswell

From: Jiri Olsa
Date: Mon Jun 02 2014 - 07:57:16 EST


hi,
Joe asked about issues with LLC-load-misses on Haswell. I tried
and found it non functional on SandyBridge (42) as well:

[jolsa@krava perf]$ ./perf stat -e LLC-load-misses ls
...

Performance counter stats for 'ls':

<not supported> LLC-load-misses

0.007195547 seconds time elapsed


both SandyBridge (42 and 45) share following config arrays:
snb_hw_cache_event_ids and snb_hw_cache_extra_regs

but have different 'x86_pmu.extra_regs' which makes LLC-load-misses
event fail (in valid_mask check) in x86_pmu_extra_regs function

Haswell is sharing the same extra regs/ids config as SandyBridge (42),
so it suffers in the same way.

Not sure if thats known issue, but it looks like we need special
set of snb_hw_cache_event_ids for SandyBridge (42) ?

thanks for info,
jirka
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