Re: [PATCH v8 10/13] x86/resctrl: Add sysfs interface to write mbm_total_bytes_config

From: Peter Newman
Date: Mon Nov 07 2022 - 05:22:09 EST


Hi Babu,

On Fri, Nov 04, 2022 at 03:01:09PM -0500, Babu Moger wrote:
> + /*
> + * When an Event Configuration is changed, the bandwidth counters
> + * for all RMIDs and Events will be cleared by the hardware. The
> + * hardware also sets MSR_IA32_QM_CTR.Unavailable (bit 62) for
> + * every RMID on the next read to any event for every RMID.
> + * Subsequent reads will have MSR_IA32_QM_CTR.Unavailable (bit 62)
> + * cleared while it is tracked by the hardware. Clear the
> + * mbm_local and mbm_total counts for all the RMIDs.
> + */
> + memset(d->mbm_local, 0, sizeof(struct mbm_state) * r->num_rmid);
> + memset(d->mbm_total, 0, sizeof(struct mbm_state) * r->num_rmid);

Looking around, I can't find a reader for mbm_total anymore. It looks
like the last place it was used went away in James's recent change:

https://lore.kernel.org/all/20220902154829.30399-19-james.morse@xxxxxxx

Are we supposed to be clearing arch_mbm_total now?

Thanks!
-Peter