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 CPU support an MSR that can partition the RMID counters in the same way. This allows for monitoring features to be used (with the caveat that memory accesses between different SNC NUMA nodes may still not be counted accurately. Note that this patch series improves resctrl reporting considerably on systems with SNC enabled, but there will still be some anomalies for processes accessing memory from other sub-NUMA nodes. Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> --- Please ignore v7 posting. There was some glitch in how I created the patches with "git format-patch" that meant part 0004 would not apply. Changes since v6: * Fixed spelling of "accurately" in cover letter. * Applied changes from Peter Newman's review Link: https://lore.kernel.org/r/CALPaoChB5ryT96ZZBQb6+3=xO+A0uR-ToN0TWqUjLJ7bgi==Rg@xxxxxxxxxxxxxx (and follow-on posts against other patches in the v6 series). See comments in indivdual patches for specific details. Added Peter's "Reviewed-by" to parts 4-7.q Tony Luck (8): 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: Sub NUMA Cluster detection and enable x86/resctrl: Update documentation with Sub-NUMA cluster changes Documentation/arch/x86/resctrl.rst | 23 +- include/linux/resctrl.h | 85 +++-- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kernel/cpu/resctrl/internal.h | 66 ++-- arch/x86/kernel/cpu/resctrl/core.c | 400 +++++++++++++++++----- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 58 ++-- arch/x86/kernel/cpu/resctrl/monitor.c | 58 ++-- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 14 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 132 +++---- 9 files changed, 591 insertions(+), 246 deletions(-) base-commit: 6465e260f48790807eef06b583b38ca9789b6072 -- 2.41.0
