Re: [RFC PATCH 01/19] x86,fs/resctrl: Add support for Global Bandwidth Enforcement (GLBE)

[Fenghua Yu <fenghuay@nvidia.com>]

Hi, Reinette,

 > What if, instead, it looks something like:
 >
 >info/
 >└── MB/
 >    └── resource_schemata/
 >        ├── GMB/
 >        │   ├── max:4096
 >        │   ├── min:1
 >        │   ├── resolution:1
 >        │   ├── scale:1
 >        │   ├── tolerance:0
 >        │   ├── type:scalar linear
 >        │   └── unit:GBps
 >        └── MB/
 >            ├── max:8192
 >            ├── min:1
 >            ├── resolution:8
 >            ├── scale:1
 >            ├── tolerance:0
 >            ├── type:scalar linear
 >            └── unit:GBps

May I have 2 comments?

1. This directory is for both info and control, right?

"info" is a read-only directory:
dr-xr-xr-x 8 root root 0 Feb 23 12:50 info

And its name suggests it's for info only as well.

Instead of mixing legal info and control together, is it better to add a 
new "control" or "config" directory in /sys/fs/resctrl for this control 
and info purpose?

2. This control method seems only handles global control for resources. 
But what if a control is per domain and per closid/partid?
For example, MPAM has a hardlimit control per mem bandwidth allocation 
domain per partid. When hardlimit is enabled, MPAM hardware enforces 
hard limit of MBW max. This can not be controlled globally.

For this kind of per partid per domain control, propose 
config_schemata/control_schemata file:

partition X/
	control_schemata (or config_schemata):
		MB_hardlimit: 0=0/1;1=0/1;...

Is this reasonable?

Thanks.

-Fenghua