Re: Multi-Volume Archive + Live Data Playback for PCP Client Tools

["Frank Ch. Eigler" <fche@xxxxxxxxxx>]

Hi, Ken -

> >I don't know how pervasive this situation would be, but if it's not
> >too hard to support, we should.  (e.g., we could track metrics across
> >archives by name rather than pmid.)
> 
> This is not pervasive at all ... this is the only PMDA I am aware of 
> that behaves like this.

(Well, the cgroup.* PMNS hierarchy may be similarly affected, but that
is due for a revamp.)


> And I think I would be lobbying for the PMDA to be different, not
> the archive handling to be different. [...]  allow the papi pmda to
> maintain a consistent and persistent metric name to low-order bits
> of the PMID mapping. [...]

I see what you mena, but unfortunately, the PAPI event code space (at
least 32 bits) is much larger than the PMID low-order bits space, is
not densely encoded, and bound to get worse when we address counters
with extra option flags, "uncore" counters, and per-process/-cgroup.


- FChE