Re: [PATCH v7 4/8] x86/resctrl: Add comments on RFTYPE flags hierarchy

From: Moger, Babu
Date: Thu Aug 17 2023 - 13:08:53 EST


Hi Reinette,

On 8/17/23 10:37, Reinette Chatre wrote:
> Hi Babu,
>
> On 8/17/2023 7:20 AM, Moger, Babu wrote:
>
>> Yea. We can go with it. How about adding a little note about directories?
>> That might be easy to compare directory structure on a systems with these
>> flags. Something like this.
>
>
> Thank you for improving it.
>
>> + *
>> + * RESCTRL filesystem has two main components
>> + * a. info
>> + * b. base
>> + *
>> + * /sys/fs/resctrl/
>> + * |
>> + * --> info (Top level directory named "info". Contains files that
>> + * | provide details on control and monitoring resources.)
>> + * |
>> + * --> base (Root directory associated with default resource group
>> + * as well as directories created by user for MON and CTRL
>> + * groups. Contains files to interact with MON and CTRL
>> + * groups.)
>> + *
>> + * Note: resctrl does not use flags for directories. Directories are
>> + * created based on the resource type. Added directories below
>> + * for better understanding.
>
> This is very helpful. How about a more specific "resctrl uses flags for
> files, not for directories. Directories are ..."
>
Sure.

>> + *
>> + * info directory structure
>> + * ------------------------------------------------------------------
>> + * --> RFTYPE_INFO
>> + * directory: info
>
> directory -> Directory ? (for all directory/directories instances)

Sure.

>
>> + * --> RFTYPE_TOP (Files in top level of info directory)
>> + * Files: last_cmd_status
>
> (nitpick) Considering the directory vs directories, maybe this can be "File:"
> until more files are added.

Yes.

>
>> + *
>> + * --> RFTYPE_MON (Files for all monitoring resources)
>> + * directory: L3_MON
>
> Should this not be below RFTYPE_RES_CACHE?

This is kind of odd. I know why you are saying it. Wouldn't it confuse the
user? Then, it feels like mon_features and num_rmids don't belong L3_MON.


>> + * Files: mon_features, num_rmids
>
>
>
>> + *
>> + * --> RFTYPE_RES_CACHE (Files for cache monitoring
>> resources)
>> + * Files: max_threshold_occupancy,
>> + * mbm_total_bytes_config,
>> + * mbm_local_bytes_config
>> + *
>> + * --> RFTYPE_CTRL (Files for all control resources)
>> + * Files: num_closids
>
> Maybe this should just be "File:" for now?

Sure.

>
>> + *
>> + * --> RFTYPE_RES_CACHE (Files for cache control
>> resources)
>> + * directories: L2,L3
>
> Please add a space after the comma.

Sure

>
>> + * Files: bit_usage, cbm_mask, min_cbm_bits,
>> + * shareable_bits
>
> The extra indent is not clear to me. Did you do it to represent
> a hierarchy or just to line up the ":"?

This is to line up with :. I can fix it.

Just wondering how do you notice these tabs? My linux diff does not show
any difference. Are you using any utilities to see these tabs?

>
>
>> + *
>> + * --> RFTYPE_RES_MB (Files for memory control resources)
>> + * directories: MB,SMBA
>
> Space after comma here also.

Sure.

>
>> + * Files: bandwidth_gran, delay_linear,
>> + * min_bandwidth, thread_throttle_mode
>> + *
>> + * base directory structure
>> + * ------------------------------------------------------------------
>> + * --> RFTYPE_BASE (Files common for both MON and CTRL groups)
>> + * Files: cpus, cpus_list, tasks
>> + *
>> + * --> RFTYPE_CTRL (Files only for CTRL group)
>> + * Files: mode, schemata, size
>>
>>
>
> Thank you very much.
>
> Reinette

--
Thanks
Babu Moger