Re: [PATCH v9 19/26] x86/resctrl: Add the interface to unassign a MBM counter

From: Peter Newman
Date: Mon Nov 04 2024 - 09:16:20 EST


Hi Babu,

On Wed, Oct 30, 2024 at 12:25 AM Babu Moger <babu.moger@xxxxxxx> wrote:
>
> The mbm_cntr_assign mode provides a limited number of hardware counters
> that can be assigned to an RMID, event pair to monitor bandwidth while
> assigned. If all counters are in use, the kernel will show an error
> message: "Out of MBM assignable counters" when a new assignment is
> requested. To make space for a new assignment, users must unassign an
> already assigned counter.
>
> Introduce an interface that allows for the unassignment of counter IDs
> from both the group and the domain. Additionally, ensure that the global
> counter is released if it is no longer assigned to any domains.

This seems unnecessarily restrictive. What's wrong with monitoring
different groups in different domains?


-Peter