Re: [PATCH v8 07/25] x86/resctrl: Introduce the interface to display monitor mode
From: Moger, Babu
Date: Thu Oct 10 2024 - 11:01:01 EST
Hi Tony,
Thanks for reviewing the patches.
On 10/9/24 17:42, Tony Luck wrote:
> On Wed, Oct 09, 2024 at 12:39:32PM -0500, Babu Moger wrote:
>> +"mbm_assign_mode":
>> + Reports the list of monitoring modes supported. The enclosed brackets
>> + indicate which mode is enabled.
>> + ::
>> +
>> + cat /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
>> + [mbm_cntr_assign]
>> + default
>> +
>> + "mbm_cntr_assign":
>> +
>> + In mbm_cntr_assign mode user-space is able to specify which control
>> + or monitor groups in resctrl should have a counter assigned using the
>> + 'mbm_assign_control' file. The number of counters available is described
>> + in the 'num_mbm_cntrs' file. Changing the mode may cause all counters on
>> + a resource to reset.
>> +
>> + The mode is useful on platforms which support more control and monitor
>> + groups than hardware counters, meaning 'unassigned' control or monitor
>> + groups will report 'Unavailable' or count the traffic in an unpredictable
>> + way.
>> +
>> + AMD Platforms with ABMC (Assignable Bandwidth Monitoring Counters) feature
>> + enable this mode by default so that counters remain assigned even when the
>> + corresponding RMID is not in use by any processor.
>> +
>> + "default":
>> +
>> + By default resctrl assumes each control and monitor group has a hardware
>> + counter. Hardware that does not support 'mbm_cntr_assign' mode will still
>> + allow more control or monitor groups than 'num_rmids' to be created. In
>
> Should that be s/num_rmids/num_mbm_cntrs/ ?
It is actually num_rmids here as in default mode, num_rmid_cntrs are not
available.
--
Thanks
Babu Moger