Re: [PATCH v10 09/10] x86/resctrl: Add support for the files for MON groups only

From: Reinette Chatre
Date: Wed Sep 27 2023 - 14:35:21 EST


Hi Babu,

On 9/15/2023 3:42 PM, Babu Moger wrote:
> There are 3 types resctrl root files.

Considering patch #4, should this be "base"?

> 1. RFTYPE_BASE : Files common for both MON and CTRL groups
> 2. RFTYPE_BASE | RFTYPE_CTRL : Files only for CTRL groups

If (1) is accurate then I cannot see how (2) can be accurate.

> 3. RFTYPE_BASE | RFTYPE_MON : Files only for MON groups

Same here.

>
> Files only for the MON groups are not supported now. Add the
> support to create these files.

This is not accurate. Files "only for the MON groups" are
actually the only monitor files that *are* supported. The
problem being fixed here is that monitor files are
not supported for CTRL_MON groups.

I made an attempt at rewriting this commit message but I am
doing it quite quickly so please do improve it:

Files unique to monitoring groups have the
RFTYPE_MON flag. When a new monitoring group is created
the resctrl files with flags RFTYPE_BASE (files common
to all resource groups) and RFTYPE_MON (files unique
to monitoring groups) are created to support interacting with
the new monitoring group.

A resource group can support both monitoring and control,
also termed a CTRL_MON resource group. CTRL_MON groups should
get both monitoring and control resctrl files but that
is not the case. Only the RFTYPE_BASE and RFTYPE_CTRL files
are created for CTRL_MON groups. This is not a problem
because there are no monitoring specific files with the
RFTYPE_MON flag associated with resource groups.

A later patch introduces the first RFTYPE_MON file for
resource groups so fix resctrl file creation for CTRL_MON
groups to ensure that monitoring files, those with the
RFTYPE_MON flag, are also created.

> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---

I only have feedback about the changelog. The patch looks good to me.

Reinette