RE: [PATCH v11 00/23] x86/resctrl : Support AMD Assignable Bandwidth Monitoring Counters (ABMC)

[Luck, Tony]

> Yes, although there is some hard-to-avoid fuzz about the precise
> meaning of "local" and "total".

Things are only getting fuzzier with mixed DDR and CXL memory.

> As Reinette pointed out, there is the also the possibility of adding
> new named events other than "local" and "total" if we find that some
> kinds of event don't fit these categories.

Not just new names, new scopes too. Patches coming later this year
that would present:

$ cd sys/fs/resctrl
$ cat mon_data/mon_PKG_00/llc_stalls
779762866739

I.e. a way to cheaply collect some "perf" like events across
all CPUs on a package that executed jobs with a specific RMID.

Of course this can be done with perf today, but the cost to collect
this data from heavily multi-threaded workloads that context switch
rapidly is very high.

-Tony