Re: [PATCH v1 17/31] x86/resctrl: Move mbm_cfg_mask to struct rdt_resource

Dave Martin
2024-04-11T14:16:52Z

On Mon, Apr 08, 2024 at 08:21:24PM -0700, Reinette Chatre wrote:
> Hi James,
>
> On 3/21/2024 9:50 AM, James Morse wrote:
> > The mbm_cfg_mask field lists the bits that user-space can set when
> > configuring an event. This value is output via the last_cmd_status
> > file.
> >
> > Once the filesystem parts of resctrl are moved to live in /fs/, the
> > struct rdt_hw_resource is inaccessible to the filesystem code. Because
> > this value is output to user-space, it has to be accessible to the
> > filesystem code.
> >
> > Move it to struct rdt_resource.
> >
> > Signed-off-by: James Morse <james.morse@arm.com>
>
> ..
>
> > diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
> > index 975b80102fbe..8a7367d1ce45 100644
> > --- a/include/linux/resctrl.h
> > +++ b/include/linux/resctrl.h
> > @@ -140,6 +140,8 @@ struct resctrl_membw {
> > * @format_str: Per resource format string to show domain value
> > * @evt_list: List of monitoring events
> > * @fflags: flags to choose base and info files
> > + * @mbm_cfg_mask: Bandwidth sources that can be tracked when Bandwidth
> > + * Monitoring Event Configuration (BMEC) is supported.

[...]

> Reinette
>
> BMEC is an AMD term. If MPAM is planning to use this member then this comment
> should be made generic.

MPAM can (at least) filter reads and/or writes, and it looks like James
is expecting to support this.

However, it probably does make sense to keep the comments neutral in a
common header.

Would the following work?

* @ mbm_cfg_mask: Arch-specific event configuration flags

I think that's broad enough to cover all bases, but I'll wait for your
response.

Cheers
---Dave