Re: [PATCH v3 00/12] [PATCH v3 00/12] x86/resctrl: Add kernel-mode (e.g., PLZA) support to the resctrl subsystem

[Luck, Tony]

On Thu, Apr 30, 2026 at 06:24:45PM -0500, Babu Moger wrote:
> 
> Hi,
> 
> This series adds support for AMD's Privilege-Level Zero Association
> (PLZA) so kernel work can be assigned to a resctrl group, and wires it
> up through a small generic "kernel mode" (kmode) layer in fs/resctrl
> so future architectures can plug in without touching core resctrl.
> 
> The features are documented in:
>  
>    AMD64 Zen6 Platform Quality of Service (PQOS) Extensions,
>    Publication # 69193 Revision 1.00, Issue Date March 2026
>  
> available at https://bugzilla.kernel.org/show_bug.cgi?id=206537
> 
> The patches are based on top of commit (7.1.0-rc1)
> Commit 3382329a309d Merge branch into tip/master: 'timers/clocksource'.

Hi Babu,

Have you had any thoughts about a resctrl selftest for PLZA?

I'm not sure there are any easy ways to show that PLZA is effective for
MBA control (as most normal system calls don't do enough to easily detect
whether the kernel CLOSID is applied). But perhaps you have some ideas for this?

A test that sets global_assign_ctrl_assign_mon_per_cpu mode with a dedicated
RMID to track kernel memory traffic would easily show MBM and llc_occupancy
numbers for kernel activity.

-Tony