Re: [PATCH v1 29/31] fs/resctrl: Add boiler plate for external resctrl code

Dave Martin
2024-04-12T16:23:42Z

Hi Babu,

[see below]

On Thu, Apr 11, 2024 at 10:42:48AM -0700, Reinette Chatre wrote:
> Hi Dave,
>
> On 4/11/2024 7:27 AM, Dave Martin wrote:
> > On Mon, Apr 08, 2024 at 08:41:04PM -0700, Reinette Chatre wrote:
> >> Hi James,
> >>
> >> On 3/21/2024 9:51 AM, James Morse wrote:
> >>> Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
> >>> for the common parts of the resctrl interface and make X86_CPU_RESCTRL
> >>> depend on this.
> >>>
> >>> Signed-off-by: James Morse <james.morse@arm.com>

[...]

> >>> diff --git a/fs/resctrl/Kconfig b/fs/resctrl/Kconfig
> >>> new file mode 100644
> >>> index 000000000000..36a1ddbe6c21
> >>> --- /dev/null
> >>> +++ b/fs/resctrl/Kconfig
> >>
> >> Could you please review the contents of this file for
> >> appropriate line length and consistent tab usage?
> >
> > Noted.
> >
> >>> @@ -0,0 +1,23 @@
> >>> +config RESCTRL_FS
> >>> + bool "CPU Resource Control Filesystem (resctrl)"
> >>> + depends on ARCH_HAS_CPU_RESCTRL
> >>> + select KERNFS
> >>> + select PROC_CPU_RESCTRL if PROC_FS
> >>> + help
> >>> + Resctrl is a filesystem interface
> >>> + to control allocation and
> >>> + monitoring of system resources
> >>> + used by the CPUs.
> >
> > (Not quite a haiku, but I don't know how many syllables "resctrl"
> > counts as...)
> >
> > Since this is the Kconfig user's primary knob for enabling resctrl,
> > maybe flesh this out and make it a bit more generic and newbie-friendly?
> > Something like:
> >
> > Some architectures provide hardware facilities to group tasks and
> > monitor and control their usage of memory system resources such as
> > caches and memory bandwidth. Examples of such facilities include
> > Intel's Resource Director Technology (Intel(R) RDT) and AMD's
> > Platform Quality of Service (AMD QoS).
>
> Nit: We should double check with AMD how they want to refer to their
> feature. Their contribution to the resctrl docs used the term you provide
> but their spec uses PQOS.

Babu, do you have a view on this?

Initially I just pasted this across from the existing text in
resctrl.rst and arch/x86/Kconfig.

Looking at the AMD's spec though, I'd probably follow Reinette's
suggestion and go for:

[...] AMD's Platform Quality of Service (PQOS)

but I'm happy to take your recommendation if you think AMD would prefer
different text here.

Cheers
---Dave