Re: [PATCH 0/2] x86/resctrl: Support wider MBM counters

From: Reinette Chatre
Date: Thu Apr 23 2020 - 12:40:32 EST


Hi Thomas and Borislav,

On 4/1/2020 10:51 AM, Reinette Chatre wrote:
> Memory Bandwidth Monitoring (MBM) is an Intel Resource Director
> Technology (RDT) feature that tracks Total and Local bandwidth
> generated which misses the L3 cache.
>
> The original Memory Bandwidth Monitoring (MBM) architectural
> definition defines counters of up to 62 bits and the first-generation
> MBM implementation uses 24 bit counters. Software is required to poll
> at 1 second or faster to ensure that data is retrieved before a counter
> rollover occurs more than once under worst conditions.
>
> As system bandwidths scale the software requirement is maintained with
> the introduction of a per-resource enumerable MBM counter width.
>
> This series adds support for the new enumerable MBM counter width.
>
> Details about the feature can be found in Chapter 9 of the most
> recent Intel ISE available from
> https://software.intel.com/sites/default/files/managed/c5/15/architecture-instruction-set-extensions-programming-reference.pdf
>
> Reinette Chatre (2):
> x86/resctrl: Maintain MBM counter width per resource
> x86/resctrl: Support CPUID enumeration of MBM counter width
>
> arch/x86/include/asm/processor.h | 1 +
> arch/x86/kernel/cpu/common.c | 5 +++++
> arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 8 ++++---
> arch/x86/kernel/cpu/resctrl/internal.h | 15 ++++++++++---
> arch/x86/kernel/cpu/resctrl/monitor.c | 27 ++++++++++++++++-------
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +-
> 6 files changed, 43 insertions(+), 15 deletions(-)
>


Would it be possible to consider this for inclusion in v5.8?

Thank you

Reinette

ps. Upon your consideration I am planning to follow up with same
the question for the next resctrl new feature series available
at:https://lore.kernel.org/lkml/cover.1586801373.git.reinette.chatre@xxxxxxxxx/

You could view outstanding resctrl changes at branch resctrl/next of
https://github.com/rchatre/linux.git