This is the re-worked version of this series that I promised to post yesterday. Check that e-mail for the arguments for this alternate approach. https://lore.kernel.org/all/ZbhLRDvZrxBZDv2j@agluck-desk3/ Apologies to Drew Fustini who I'd somehow dropped from later versions of this series. Drew: you had made a comment at one point that having different scopes within a single resource may be useful on RISC-V. Version 14 included that, but it's gone here. Maybe multiple resctrl "struct resource" for a single h/w entity like L3 as I'm doing in this version could work for you too? Patches 1-5 are almost completely rewritten based around the new idea to give CMT and MBM their own "resource" instead of sharing one with L3 CAT. This removes the need for separate domain lists, and thus most of the churn of the previous version of this series. Patches 6-8 are largely unchanged. But I removed all the Reviewed and Tested tags since they are now built on a completely different base. Patches are against tip x86/cache: fc747eebef73 ("x86/resctrl: Remove redundant variable in mbm_config_write_domain()") Re-work doesn't affect the v14 cover letter, so pasting it here: 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 monitoring features to be used. With the caveat that users must be aware that Linux may migrate tasks more frequently between SNC nodes than between "regular" NUMA nodes, so reading counters from all SNC nodes may be needed to get a complete picture of activity for tasks. Cache and memory bandwidth allocation features continue to operate at the scope of the L3 cache. Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> Tony Luck (8): x86/resctrl: Split the RDT_RESOURCE_L3 resource x86/resctrl: Move all monitoring functions to RDT_RESOURCE_L3_MON x86/resctrl: Prepare for non-cache-scoped resources x86/resctrl: Add helper function to look up domain_id from scope x86/resctrl: Add "NODE" as an option for resource 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 | 25 ++- include/linux/resctrl.h | 10 +- arch/x86/include/asm/msr-index.h | 1 + arch/x86/kernel/cpu/resctrl/internal.h | 3 + arch/x86/kernel/cpu/resctrl/core.c | 181 +++++++++++++++++++++- arch/x86/kernel/cpu/resctrl/monitor.c | 28 ++-- arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 6 +- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 12 +- 8 files changed, 236 insertions(+), 30 deletions(-) base-commit: fc747eebef734563cf68a512f57937c8f231834a -- 2.43.0
