Skylake minimal counts

Hi all!

During testing on a Skylake-SP, I have noticed that most of the Skylake
events have "minimum:2000003" set, even for events that used to have much
lower minimum counts on various older micro-architectures, such as Haswell,
Ivy Bridge, etc.

An example might be cpu_clk_unhalted which has usually 6000, except of the
following models:

Goldmont:     minimum:2000003
Skylake:      minimum:2000003
Westmere:     minimum:100000

Similarly, for inst_retired, for previous CPUs, it was usually 6000, except of:

Broadwell:    minimum:2000003
Goldmont:     minimum:2000003
Haswell:      minimum:2000003
Sandy Bridge: minimum:2000000
Skylake:      minimum:2000003
Westmere:     minimum:2000003

(e.g. Atom, Core2, Nehalem are 6000)

I know that the minimal counts are nothing precise and were determined rather
"randomly", but for Skylakes, it seems that 2000003 is just the "default for
everything" except of some exceptions...

Since OProfile does not allow users to enforce a lower value there, the 2000003
values seem to be pretty limiting, don't they?

Shouldn't they be re-configured? If you think so, I might do that. However,
in such case, I am curious how would you do it (which load/criteria would you
use)...

Cheers,
Michael


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