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From: Peter Newman <peternewman@google.com>
Date: Thu, 4 Apr 2024 12:08:43 -0700
Message-ID: <CALPaoCheW=Jz2R3gMKcgwQe6ONDrRqu3tUxeg=A3USg6BC8buA@mail.gmail.com>
Subject: Re: [RFC PATCH v3 00/17] x86/resctrl : Support AMD Assignable
 Bandwidth Monitoring Counters (ABMC)
To: Babu Moger <babu.moger@amd.com>
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Hi Babu,

On Thu, Mar 28, 2024 at 6:07=E2=80=AFPM Babu Moger <babu.moger@amd.com> wro=
te:
>    The list follows the following format:
>
>        * Default CTRL_MON group:
>                "//<domain_id>=3D<assignment_flags>"
>
>        * Non-default CTRL_MON group:
>                "<CTRL_MON group>//<domain_id>=3D<assignment_flags>"
>
>        * Child MON group of default CTRL_MON group:
>                "/<MON group>/<domain_id>=3D<assignment_flags>"
>
>        * Child MON group of non-default CTRL_MON group:
>                "<CTRL_MON group>/<MON group>/<domain_id>=3D<assignment_fl=
ags>"
>
>        Assignment flags can be one of the following:
>
>         t  MBM total event is assigned
>         l  MBM local event is assigned
>         tl Both total and local MBM events are assigned
>         _  None of the MBM events are assigned
>
>         Examples:
>
>         # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
>         non_defult_group//0=3Dtl;1=3Dtl;2=3Dtl;3=3Dtl;4=3Dtl;5=3Dtl;6=3Dt=
l;7=3Dtl;
>         non_defult_group/non_default_mon1/0=3Dtl;1=3Dtl;2=3Dtl;3=3Dtl;4=
=3Dtl;5=3Dtl;6=3Dtl;7=3Dtl;
>         //0=3Dtl;1=3Dtl;2=3Dtl;3=3Dtl;4=3Dtl;5=3Dtl;6=3Dtl;7=3Dtl;
>         /default_mon1/0=3Dtl;1=3Dtl;2=3Dtl;3=3Dtl;4=3Dtl;5=3Dtl;6=3Dtl;7=
=3Dtl;
>
>         There are four groups and all the groups have local and total eve=
nt assigned.
>
>         "//" - This is a default CONTROL MON group
>
>         "non_defult_group//" - This is non default CONTROL MON group
>
>         "/default_mon1/"  - This is Child MON group of the defult group
>
>         "non_defult_group/non_default_mon1/" - This is child MON group of=
 the non default group
>
>         =3Dtl means both total and local events are assigned.

I recall there was supposed to be a way to perform the same update on
all domains together so that it isn't tedious to not do per-domain
customizations. (And also to avoid serializing programming all the
domains the same way.)


>
>  .../admin-guide/kernel-parameters.txt         |   2 +-
>  Documentation/arch/x86/resctrl.rst            | 144 ++++
>  arch/x86/include/asm/cpufeatures.h            |   1 +
>  arch/x86/include/asm/msr-index.h              |   2 +
>  arch/x86/kernel/cpu/cpuid-deps.c              |   3 +
>  arch/x86/kernel/cpu/resctrl/core.c            |  25 +-
>  arch/x86/kernel/cpu/resctrl/internal.h        |  56 +-
>  arch/x86/kernel/cpu/resctrl/monitor.c         |  24 +-
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c        | 714 +++++++++++++++++-
>  arch/x86/kernel/cpu/scattered.c               |   1 +
>  include/linux/resctrl.h                       |  12 +
>  11 files changed, 964 insertions(+), 20 deletions(-)
>
> --
> 2.34.1
>

This should be fine for me to get started with. I'll see if I can work
backwards from the patches adding the parsing code to see how I'll
work the software implementation in.

Thanks!
-Peter