Re: [PATCH v5 20/20] x86/resctrl: Introduce interface to modify assignment states of the groups

Peter Newman
2024-07-25T00:04:07Z

Hi Babu,

On Wed, Jul 3, 2024 at 2:51 PM Babu Moger <babu.moger@amd.com> wrote:
>
> Introduce the interface to enable events in ABMC mode.
>
> Events can be enabled or disabled by writing to file
> /sys/fs/resctrl/info/L3_MON/mbm_control
>
> Format is similar to the list format with addition of op-code for the
> assignment operation.
> "<CTRL_MON group>/<MON group>/<op-code><flags>"
>
> Format for specific type of groups:
>
> * Default CTRL_MON group:
> "//<domain_id><op-code><flags>"
>
> * Non-default CTRL_MON group:
> "<CTRL_MON group>//<domain_id><op-code><flags>"
>
> * Child MON group of default CTRL_MON group:
> "/<MON group>/<domain_id><op-code><flags>"
>
> * Child MON group of non-default CTRL_MON group:
> "<CTRL_MON group>/<MON group>/<domain_id><op-code><flags>"

Just a reminder, Reinette and I had discussed[1] omitting the
domain_id for performing the same operation on all domains.

I would really appreciate this, otherwise our most typical operations
could be really tedious and needlessly serialized.

# cat mbm_control
//0=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;8=tl;9=tl;10=tl;11=tl;12=tl;13=tl;14=tl;15=tl;16=tl;17=tl;18=tl;19=tl;20=tl;21=tl;22=tl;23=tl;24=tl;25=tl;26=tl;27=tl;28=tl;29=tl;30=tl;31=tl;
# echo '//-l' > mbm_control
-bash: echo: write error: Invalid argument
# cat ../last_cmd_status
Missing domain id

If you can't get to it in this series, I'll push a
scalability-oriented series after the basic assignment support is
merged.

Thanks!
-Peter

[1] https://lore.kernel.org/lkml/CALPaoChcJq5zoPchB2j0aM+nZpQe1xoo7w2QQUjtH+c58Yyxag@mail.gmail.com/