This is a long standing bug with the l1-dcache-stores generic event on
AMD machines. My perf_event testsuite has been complaining about this
for years and I'm finally getting around to trying to get it fixed.
The data_cache_refills:system event does not make sense for l1-dcache-stores.
Maybe this was a typo and it was meant to be for l1-dcache-store-misses?
In any case, the values returned are nowhere near correct for l1-dcache-stores
and in fact the umask values for the event have completely changed with
fam15h so it makes even less sense than ever. So just remove it.