Re: [RFC PATCH v3 00/17] x86/resctrl : Support AMD Assignable Bandwidth Monitoring Counters (ABMC)

Peter Newman
2024-04-04T19:08:55Z

Hi Babu,

On Thu, Mar 28, 2024 at 6:07 PM Babu Moger <babu.moger@amd.com> wrote:
> The list follows the following format:
>
> * Default CTRL_MON group:
> "//<domain_id>=<assignment_flags>"
>
> * Non-default CTRL_MON group:
> "<CTRL_MON group>//<domain_id>=<assignment_flags>"
>
> * Child MON group of default CTRL_MON group:
> "/<MON group>/<domain_id>=<assignment_flags>"
>
> * Child MON group of non-default CTRL_MON group:
> "<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"
>
> 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=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;
> non_defult_group/non_default_mon1/0=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;
> //0=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;
> /default_mon1/0=tl;1=tl;2=tl;3=tl;4=tl;5=tl;6=tl;7=tl;
>
> There are four groups and all the groups have local and total event 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
>
> =tl 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