Hi Reinette,
On 8/16/24 16:34, Reinette Chatre wrote:
> Hi Babu,
>
> On 8/6/24 3:00 PM, Babu Moger wrote:
>> The ABMC feature provides an option to the user to assign a hardware
>
> Here and in all patches, when referring to resctrl fs please use the more
> generic "mbm_assign_cntr" mode to distinguish it from the
> hardware/architecture
> specific code that involves ABMC. Something like
>
> "The ABMC feature provides" -> ""mbm_cntr_assign" mode provides"
Sure.
>
> I also think that being explicit with this separation will help us to see
> gaps in interface between resctrl fs and arch.
Yes.
>
>> counter to an RMID and monitor the bandwidth as long as the counter is
>
> Please clarify the scope of this feature. Above mentions that a counter is
> assigned to an RMID but later it is mentioned that the counter is assigned
> to an event. Perhaps consistently mention that a counter is assigned to
> a RMID,event pair?
Yes.
"a counter is assigned to an RMID,event pair" gives more clarity.
Will changes it.
>
>> assigned. Number of assignments depend on number of monitoring counters
>> available.
>>
>> Provide the interface to display the number of monitoring counters
>> supported.
>>
>> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
>> ---
>> v6: No changes.
>>
>> v5: Changed the display name from num_cntrs to num_mbm_cntrs.
>> Updated the commit message.
>> Moved the patch after mbm_mode is introduced.
>>
>> v4: Changed the counter name to num_cntrs. And few text changes.
>>
>> v3: Changed the field name to mbm_assign_cntrs.
>>
>> v2: Changed the field name to mbm_assignable_counters from abmc_counte
>> ---
>> Documentation/arch/x86/resctrl.rst | 3 +++
>> arch/x86/kernel/cpu/resctrl/monitor.c | 2 ++
>> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++++++++
>> 3 files changed, 21 insertions(+)
>>
>> diff --git a/Documentation/arch/x86/resctrl.rst
>> b/Documentation/arch/x86/resctrl.rst
>> index d4ec605b200a..fe9f10766c4f 100644
>> --- a/Documentation/arch/x86/resctrl.rst
>> +++ b/Documentation/arch/x86/resctrl.rst
>> @@ -291,6 +291,9 @@ with the following files:
>> as long as there are enough RMID counters available to support
>> number
>> of monitoring groups.
>> +"num_mbm_cntrs":
>> + The number of monitoring counters available for assignment.
>> +
>> "max_threshold_occupancy":
>> Read/write file provides the largest value (in
>> bytes) at which a previously used LLC_occupancy
>> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c
>> b/arch/x86/kernel/cpu/resctrl/monitor.c
>> index 5e8706ab6361..83329cefebf7 100644
>> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
>> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
>> @@ -1242,6 +1242,8 @@ int __init rdt_get_mon_l3_config(struct
>> rdt_resource *r)
>> r->mon.num_mbm_cntrs = (ebx & 0xFFFF) + 1;
>> if (WARN_ON(r->mon.num_mbm_cntrs > 64))
>> r->mon.num_mbm_cntrs = 64;
>> +
>> + resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
>
> The arch code should not access the resctrl file flags. This should be
> moved to make
> the MPAM support easier. With the arch code setting
> r->mon.mbm_cntr_assignable the
> fs code can use that to set the flags. Something similar to below patch is
> needed:
> https://lore.kernel.org/lkml/20240802172853.22529-27-james.morse@xxxxxxx/
It is just moving the calls resctrl_file_fflags_init() to resctrl_init().
The rdt_resource fields are already setup here. Something like
https://lore.kernel.org/lkml/20240802172853.22529-20-james.morse@xxxxxxx/
I feel it is better done when MBAM fs/arch separation.
--
Thanks
Babu Moger
