Re: [PATCH][v3] x86/resctrl: Add task resctrl information display

From: Thomas Gleixner
Date: Wed Nov 20 2019 - 06:23:07 EST


On Wed, 20 Nov 2019, Chen Yu wrote:
> Monitoring tools that want to find out which resctrl CTRL
> and MONITOR groups a task belongs to must currently read
> the "tasks" file in every group until they locate the process
> ID.
>
> Add an additional file /proc/{pid}/resctrl to provide this
> information.
>
> For example:
> cat /proc/1193/resctrl
> CTRL_MON:/ctrl_grp0
> MON:/ctrl_grp0/mon_groups/mon_grp0

The formatting is quite ugly and I don't see why this needs to be multiple
lines and have these uppercase prefixes.

A task can only be part of one control group and of one monitoring group
which is associated to the control group. So just providing:

1) ""
2) "/"
3) "/mon_groups/mon0"
4) "/group0"
5) "/group0/mon_groups/mon1"

is simple and clear enough, i.e.:

#1: Resctrl is not available

#2: Task is part of the root group, task not associated to any monitoring
group

#3: Task is part of the root group and monitoring group mon0

#4: Task is part of control group group0, task not associated to any
monitoring group

#5: Task is part of control group group0 and monitoring group mon1

Hmm?

Thanks,

tglx