Update pcp subpackages in ELN

[yselkowitz]

https://src.fedoraproject.org/rpms/pcp/c/9515e8a51fba8ceb02438afc72985d239ce91c7b

/cc @natoscott

[natoscott]

That look's great, thanks so much @yselkowitz

[hhorak]

Thanks, let's wait with merging before @kurik or @wcohen have chance to look at.

What I'm not sure myself is explicitly listing dependencies - chan, HdrHistogram_c, js-d3-flame-graph. Those should be pulled automatically and in case PCP+grafana moves to another package to provide that functionality, those components here might be pulled unnecessarily. Is there a reason to list those dependencies explicitly, @yselkowitz?

[yselkowitz]

If you look at the commits individually, it will make more sense. They were already there, and I just copied the existing config for c10s so that the main (eln) config could be updated, while dropping an obsolete duplicate config in the process.

That being said, I agree that mere dependencies should NOT be listed for the reason you give. chan and HdrHistogram_c are still pcp deps, but can and probably should be delisted.

However js-d3-flame-graph is not a dependency of anything, and I'm having trouble finding if it ever was. @natoscott you did the Fedora package review for its addition, what purpose does it serve?

[natoscott]

@yselkowitz I believe it is/was used by perf(1). Similar/same code exists (embedded?) in grafana-pcp but I don't know all the details there - Sam Feifer may be able to provide more insight there if needed.

[yselkowitz]

OK, grafana-pcp bundles it, but that doesn't require a standalone package. I don't see anything with perf though.

Am I missing something, or is the standalone js-d3-flame-graph superfluous and can just be dropped?

[natoscott]

I think its a soft dependency, there's some docs here I just found:
https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/10/html/monitoring_and_managing_system_status_and_performance/getting-started-with-flamegraphs

[yselkowitz]

Thanks for clarifying, I delisted chan and HdrHistogram_c as discussed above, they'll stay in ELN as dependencies as long as pcp requires them.