RE: [PATCH 2/2] x86/resctrl: Don't workqueue local event counter reads
From: Luck, Tony
Date: Wed Nov 06 2024 - 12:13:09 EST
> As a refresher, the original issue that led to this situation was how
> an MPAM CSU (cache occupancy) monitor can be installed in response to
> a read request. The number of monitors is usually small (or just 1),
> so they need to be frequently installed, there can be access issues
> depending on what CPU wants to read which domain, and installing a
> monitor is a slow operation that requires waiting.
Maybe the ARM implementation should adopt a similar approach to
Babu's ABMC patches and provide an explicit mechanism to bind a
h/w counter to an instance of a monitor event. Binding on demand
when a user reads an event file seems awkward for users. Especially
of the number of counters is >1, but unknown.
-Tony