Re: [PATCH v7 12/12] Documentation/x86: Update resctrl.rst for new features

Moger, Babu
2022-10-26T20:00:50Z

Hi Reinette,

On 10/25/22 18:50, Reinette Chatre wrote:
> Hi Babu,
>
> On 10/17/2022 3:27 PM, Babu Moger wrote:
>
> ...
>
>> +"mbm_total_config", "mbm_local_config":
>> + These files contain the current event configuration for the events
>> + mbm_total_bytes and mbm_local_bytes, respectively, when the
>> + Bandwidth Monitoring Event Configuration (BMEC) feature is supported.
>> + The event configuration settings are domain specific and will affect
>> + all the CPUs in the domain.
>> +
>> + Following are the types of events supported:
>> +
>> + ==== ========================================================
>> + Bits Description
>> + ==== ========================================================
>> + 6 Dirty Victims from the QOS domain to all types of memory
>> + 5 Reads to slow memory in the non-local NUMA domain
>> + 4 Reads to slow memory in the local NUMA domain
>> + 3 Non-temporal writes to non-local NUMA domain
>> + 2 Non-temporal writes to local NUMA domain
>> + 1 Reads to memory in the non-local NUMA domain
>> + 0 Reads to memory in the local NUMA domain
>> + ==== ========================================================
>> +
>> + By default, the mbm_total_bytes configuration is set to 0x7f to count
>> + all the event types and the mbm_local_bytes configuration is set to
>> + 0x15 to count all the local memory events.
>> +
>> + Examples:
>> +
>> + * To view the current configuration::
>> + ::
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> + 0=0x7f;1=0x7f;2=0x7f;3=0x7f
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> + 0=0x15;1=0x15;3=0x15;4=0x15
>> +
>> + * To change the mbm_total_bytes to count only reads on domain 0,
>> + the bits 0, 1, 4 and 5 needs to be set, which is 110011b in binary
>> + (in hexadecimal 0x33):
>> + ::
>> +
>> + # echo "0=0x33" > /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_total_config
>> + 0=0x33;1=0x7f;2=0x7f;3=0x7f
>> +
>> + * To change the mbm_local_bytes to count all the slow memory reads
>> + on domain 1, the bits 4 and 5 needs to be set, which is 110000b
>> + in binary (in hexadecimal 0x30):
>> + ::
>> +
>> + # echo "1=0x30" > /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> +
>> + # cat /sys/fs/resctrl/info/L3_MON/mbm_local_config
>> + 0=0x15;1=0x30;3=0x15;4=0x15
>>
> The code supports modifying multiple domains with one write. To help users
> understand this it may be useful to have one of these examples do so to show
> that and how it can be done.
Sure.
>
>> "max_threshold_occupancy":
>> Read/write file provides the largest value (in
>> @@ -464,6 +539,26 @@ Memory bandwidth domain is L3 cache.
>>
>> MB:<cache_id0>=bw_MBps0;<cache_id1>=bw_MBps1;...
>>
>> +Slow Memory bandwidth Allocation (SMBA)
> bandwidth -> Bandwidth?
ok
>
>> +---------------------------------------
>> +AMD hardwares support Slow Memory bandwidth Allocation (SMBA) feature.
> hardware -> hardware?
> bandwidth -> Bandwidth?

Sure. Thanks

Babu