Re: [PATCH v8 00/13] Support for AMD QoS new features

["Moger, Babu" <babu.moger@amd.com>]

Hi Reinette and Others,

I was planning to refresh the series later this week. I have one comment
from Peter Newman.  Let me know if you have any comments.

Thanks

Babu


On 11/4/22 14:59, Babu Moger wrote:
> New AMD processors can now support following QoS features.
>
> 1. Slow Memory Bandwidth Allocation (SMBA)
>    With this feature, the QOS enforcement policies can be applied
>    to the external slow memory connected to the host. QOS enforcement
>    is accomplished by assigning a Class Of Service (COS) to a processor
>    and specifying allocations or limits for that COS for each resource
>    to be allocated.
>
>    Currently, CXL.memory is the only supported "slow" memory device. With
>    the support of SMBA feature the hardware enables bandwidth allocation
>    on the slow memory devices.
>
> 2. Bandwidth Monitoring Event Configuration (BMEC)
>    The bandwidth monitoring events mbm_total_event and mbm_local_event 
>    are set to count all the total and local reads/writes respectively.
>    With the introduction of slow memory, the two counters are not enough
>    to count all the different types are memory events. With the feature
>    BMEC, the users have the option to configure mbm_total_event and
>    mbm_local_event to count the specific type of events.
>
>    Following are the bitmaps of events supported.
>    Bits    Description
>      6       Dirty Victims from the QOS domain to all types of memory
>      5       Reads to slow memory in the non-local NUMA domain
>      4       Reads to slow memory in the local NUMA domain
>      3       Non-temporal writes to non-local NUMA domain
>      2       Non-temporal writes to local NUMA domain
>      1       Reads to memory in the non-local NUMA domain
>      0       Reads to memory in the local NUMA domain
>
> This series adds support for these features.
>
> Feature description is available in the specification, "AMD64 Technology Platform Quality of Service Extensions, Revision: 1.03 Publication # 56375
> Revision: 1.03 Issue Date: February 2022".
>
> Link: https://www.amd.com/en/support/tech-docs/amd64-technology-platform-quality-service-extensions
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=206537
> ---
> v8:
>  Changes:
>  1. Removed init attribute for rdt_cpu_has to make it available for all the files.
>  2. Updated the change log for mon_features to correct the names of config files.
>  3. Changed configuration file name from mbm_total_config to mbm_total_bytes_config.
>     This is more consistant with other changes.
>  4. Added lock protection while reading/writing the config file.
>  5. Other few minor text changes. I have been missing few comments in last couple of
>     revisions. Hope I have addressed all of them this time.
>
> v7:
>  https://lore.kernel.org/lkml/166604543832.5345.9696970469830919982.stgit@bmoger-ubuntu/
>  Changes:
>  Not much of a change. Missed one comment from Reinette from v5. Corrected it now.
>  Few format corrections from Sanjaya.
>
> v6:
>  https://lore.kernel.org/lkml/166543345606.23830.3120625408601531368.stgit@bmoger-ubuntu/
>  Summary of changes:
>  1. Rebased on top of lastest tip tree. Fixed few minor conflicts.
>  2. Fixed format issue with scattered.c.
>  3. Removed config_name from the structure mon_evt. It is not required.
>  4. The read/write format for mbm_total_config and mbm_local_config will be same
>     as schemata format "id0=val0;id1=val1;...". This is comment from Fenghua.
>  5. Added more comments MSR_IA32_EVT_CFG_BASE writng.
>  5. Few text changes in resctrl.rst 
>  
> v5:
>   https://lore.kernel.org/lkml/166431016617.373387.1968875281081252467.stgit@bmoger-ubuntu/
>   Summary of changes.
>   1. Split the series into two. The first two patches are bug fixes. So, sent them separate.
>   2. The config files mbm_total_config and mbm_local_config are now under
>      /sys/fs/resctrl/info/L3_MON/. Removed these config files from mon groups.
>   3. Ran "checkpatch --strict --codespell" on all the patches. Looks good with few known exceptions.
>   4. Few minor text changes in resctrl.rst file. 
>
> v4:
>   https://lore.kernel.org/lkml/166257348081.1043018.11227924488792315932.stgit@bmoger-ubuntu/
>   Got numerios of comments from Reinette Chatre. Addressed most of them. 
>   Summary of changes.
>   1. Removed mon_configurable under /sys/fs/resctrl/info/L3_MON/.  
>   2. Updated mon_features texts if the BMEC is supported.
>   3. Added more explanation about the slow memory support.
>   4. Replaced smp_call_function_many with on_each_cpu_mask call.
>   5. Removed arch_has_empty_bitmaps
>   6. Few other text changes.
>   7. Removed Reviewed-by if the patch is modified.
>   8. Rebased the patches to latest tip.
>
> v3:
>   https://lore.kernel.org/lkml/166117559756.6695.16047463526634290701.stgit@bmoger-ubuntu/
>   a. Rebased the patches to latest tip. Resolved some conflicts.
>      https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
>   b. Taken care of feedback from Bagas Sanjaya.
>   c. Added Reviewed by from Mingo.
>   Note: I am still looking for comments from Reinette or Fenghua.
>
> v2:
>   https://lore.kernel.org/lkml/165938717220.724959.10931629283087443782.stgit@bmoger-ubuntu/
>   a. Rebased the patches to latest stable tree (v5.18.15). Resolved some conflicts.
>   b. Added the patch to fix CBM issue on AMD. This was originally discussed
>      https://lore.kernel.org/lkml/20220517001234.3137157-1-eranian@google.com/
>
> v1:
>   https://lore.kernel.org/lkml/165757543252.416408.13547339307237713464.stgit@bmoger-ubuntu/
>
> Babu Moger (13):
>       x86/cpufeatures: Add Slow Memory Bandwidth Allocation feature flag
>       x86/resctrl: Add a new resource type RDT_RESOURCE_SMBA
>       x86/cpufeatures: Add Bandwidth Monitoring Event Configuration feature flag
>       x86/resctrl: Include new features in command line options
>       x86/resctrl: Detect and configure Slow Memory Bandwidth Allocation
>       x86/resctrl: Remove the init attribute for rdt_cpu_has()
>       x86/resctrl: Introduce data structure to support monitor configuration
>       x86/resctrl: Add sysfs interface to read mbm_total_bytes_config
>       x86/resctrl: Add sysfs interface to read mbm_local_bytes_config
>       x86/resctrl: Add sysfs interface to write mbm_total_bytes_config
>       x86/resctrl: Add sysfs interface to write mbm_local_bytes_config
>       x86/resctrl: Replace smp_call_function_many() with on_each_cpu_mask()
>       Documentation/x86: Update resctrl.rst for new features
>
>
>  .../admin-guide/kernel-parameters.txt         |   2 +-
>  Documentation/x86/resctrl.rst                 | 139 +++++++-
>  arch/x86/include/asm/cpufeatures.h            |   2 +
>  arch/x86/kernel/cpu/cpuid-deps.c              |   1 +
>  arch/x86/kernel/cpu/resctrl/core.c            |  56 +++-
>  arch/x86/kernel/cpu/resctrl/ctrlmondata.c     |   2 +-
>  arch/x86/kernel/cpu/resctrl/internal.h        |  33 ++
>  arch/x86/kernel/cpu/resctrl/monitor.c         |   7 +
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c        | 304 ++++++++++++++++--
>  arch/x86/kernel/cpu/scattered.c               |   2 +
>  10 files changed, 515 insertions(+), 33 deletions(-)
>
> --
>
-- 
Thanks
Babu Moger