Re: [PATCH v18 00/17] Add support for Sub-NUMA cluster (SNC) systems

[Maciej Wieczor-Retman]

On 2024-05-15 at 15:23:08 -0700, Tony Luck wrote:
>This series based on top of Linus upstream commit 33e02dc69afb ("Merge
>tag 'sound-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound")
>
>The Sub-NUMA cluster feature on some Intel processors partitions the CPUs
>that share an L3 cache into two or more sets. This plays havoc with the
>Resource Director Technology (RDT) monitoring features.  Prior to this
>patch Intel has advised that SNC and RDT are incompatible.
>
>Some of these CPUs support an MSR that can partition the RMID counters
>in the same way. This allows monitoring features to be used. Legacy
>monitoring files provide the sum of counters from each SNC node for
>backwards compatibility. Additional  files per SNC node provide details
>per node.
>
>Cache and memory bandwidth allocation features continue to operate at
>the scope of the L3 cache.
>
>Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
>
>---
>Changes since v17: https://lore.kernel.org/all/20240503203325.21512-1-tony.luck@xxxxxxxxx/
>
>Reinette: This is still using the per-domain display_id field as
>discussed. Would a better name make the intent clearer?
>
>Patch 7 in previous version included virtually all of the new changes.
>But that meant it was doing a lot of thinngs in a single patch
>(including reverting a dozen lines from patch 6!)
>
>So this series breaks patch 7 into nine pieces (0007..0015) for
>better documentation in commit comments of the changes, and hopefully
>easier review.
>
>Patches 0001 ... 0005:  Unchanged
>Patch 0006:             Dropped change that was reverted in v17.0007
>
>Next nine are the split of the original patch v17.0007
>Patch 0007:             Added bigger commit comment describing where
>                        this part of the series is heading and why.
>Patch 0008:             Added justification for new display_id field in struct rdt_mon_domain
>Patch 0009:             Split out a helper from mkdir_mondata_subdir()
>                        so real changes in patch 0011 are easier to see.
>Patch 0010:             Comment stealing a bit from union mon_data_bits.evtid
>Patch 0011:             Save display_id instead of a random d->id in
>                        meta data for monitor files that must sum SNC nodes
>                        Don't call mon_event_read() to initialize "sum" files
>Patch 0012:             Set domid for "sum" files to the display id, not
>			to whatever SNC domain ID is in use here. Don't
>			call mon_event_read() for "sum" files.
>Patch 0013:             No change (apart from being split out from old patch 7)
>Patch 0014:             Because of change in patch 0011 to save the
>                        display_id can no longer look up a domain using
>                        rdt_find_domain(). Instead search r->mon_domains
>                        for a match with d->display_id or d->hdr.id
>                        Drop extra arg to ___mon_event_count() also
>                        the "tmp" variable in __mon_event_count()
>Patch 0015:             Put #include <linux/cacheinfo.h> in alphabetical order
>			When SNC is disabled, keep the old check that
>			the current CPU is in the domain being read.
>			For the SNC case add comment about reading
>			monitor values from any CPU in the same L3 domain.
>
>Patch 0016:             Took alternate SNC detection algorithm from:
>                        https://lore.kernel.org/all/20240327200352.236835-11-tony.luck@xxxxxxxxx/
>                        as it is simpler. But merged in the sanity
>                        checks that make sense.
>			Converted the X86_MATCH*() usage to new model
>			that supports Intel families other than "6".
>Patch 0017:             No change
>
>
>Tony Luck (17):
>  x86/resctrl: Prepare for new domain scope
>  x86/resctrl: Prepare to split rdt_domain structure
>  x86/resctrl: Prepare for different scope for control/monitor
>    operations
>  x86/resctrl: Split the rdt_domain and rdt_hw_domain structures
>  x86/resctrl: Add node-scope to the options for feature scope
>  x86/resctrl: Introduce snc_nodes_per_l3_cache
>  x86/resctrl: Prepare for new Sub-NUMA (SNC) cluster monitor files
>  x86/resctrl: Add and initialize display_id field to struct
>    rdt_mon_domain
>  x86/resctrl: Add new fields to struct rmid_read for summation of
>    domains
>  x86/resctrl: Refactor mkdir_mondata_subdir() with a helper function
>  x86/resctrl: Allocate a new bit in union mon_data_bits
>  x86/resctrl: Create Sub-NUMA (SNC) monitor files
>  x86/resctrl: Handle removing directories in Sub-NUMA (SNC) mode
>  x86/resctrl: Sum monitor data acrss Sub-NUMA (SNC) nodes when needed
>  x86/resctrl: Fix RMID reading sanity check for Sub-NUMA (SNC) mode
>  x86/resctrl: Sub NUMA Cluster detection and enable
>  x86/resctrl: Update documentation with Sub-NUMA cluster changes
>
> Documentation/arch/x86/resctrl.rst        |  17 +
> include/linux/resctrl.h                   |  89 +++--
> arch/x86/include/asm/msr-index.h          |   1 +
> arch/x86/kernel/cpu/resctrl/internal.h    |  78 ++--
> arch/x86/kernel/cpu/resctrl/core.c        | 422 ++++++++++++++++++----
> arch/x86/kernel/cpu/resctrl/ctrlmondata.c |  70 ++--
> arch/x86/kernel/cpu/resctrl/monitor.c     | 106 ++++--
> arch/x86/kernel/cpu/resctrl/pseudo_lock.c |  26 +-
> arch/x86/kernel/cpu/resctrl/rdtgroup.c    | 267 +++++++++-----
> 9 files changed, 779 insertions(+), 297 deletions(-)
>
>
>base-commit: 33e02dc69afbd8f1b85a51d74d72f139ba4ca623
>-- 
>2.44.0
>

Tested-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>

-- 
Kind regards
Maciej Wieczór-Retman