V2 upstream submission available from: https://lore.kernel.org/lkml/cover.1586801373.git.reinette.cha...@intel.com
Changes since V2: - Rebase on top of recently merged series "x86/resctrl: Support wider MBM counters". Small change needed to take into account asm/resctrl_sched.h -> asm/resctrl.h name change. - Fix rST formatting of documentation (resctrl_ui.rst) describing new "thread_throttle_mode" resctrl file. - Use boot_cpu_has() instead of static_cpu_has() when determining what to display to user (slow path). V1 upstream submission available from: https://lore.kernel.org/lkml/cover.1585765499.git.reinette.cha...@intel.com A notable change since V1 is the inclusion of two additional patches from Fenghua Yu that introduce the new per-thread MBA feature. These changes are added to this series because they are small and closely related to the original submission. The per-thread MBA feature is a hardware advancement that requires no software interface changes. The patches added just enumerate the feature and expose it to userspace by showing "per-thread" in the new resctrl file "thread_throttle_mode" to help user applications fine tune performance. There are currently a few resctrl changes outstanding for upstream inclusion. To support their consideration all outstanding resctrl patches can be viewed at https://github.com/rchatre/linux.git (branch resctrl/next) Changes since V1 (also documented within patches to which they apply): - Rebased on top of James Morse's CDP fix (https://lore.kernel.org/lkml/20200221162105.154163-1-james.mo...@arm.com) - Remove RF_UNINITIALIZED (having uninitialized be represented with ones creates too much confusion), replace with an explicit check of rft->fflags in rdtgroup_add_files() (Fenghua Yu) - Rename MBA_THREAD_THROTTLE_MODE to MBA_THROTTLE_MODE_MASK to clarify its use as a mask (Tony Luck) - Introduce explicit MBA_THROTTLE_MODE_MAX instead of implying it is the opposite of min and use these values (min and max) explicitly whenever testing/setting the throttle mode value (Tony Luck) - Add __init attribute to thread_throttle_mode_init_intel_rw() and thread_throttle_mode_init_intel_ro() since they are only needed during initialization (Fenghua Yu) - Remove MBA_CFG MSR reads and error checking so that the patch is simpler and easier to review (Fenghua Yu) - Ensure CPU hotplug lock is taken when writing register on multiple CPUs (Fenghua Yu) - Use CPU mask already maintained as part of domains to determine which CPUs to update MBA register on (Fenghua Yu) - Maintain MBA configuration register contents to support use case when not all CPUs of a package are online when configuration is set from user space - Use seq_puts() instead of seq_printf() when simple strings are printed - Set MBA configuration to default when resctrl is unmounted - Complete rewrite of "thread_throttle_mode" documentation (Tony Luck) - Remove unnecessary checks on user input (Andy Shevchenko) - Change code style surrounding usage of sysfs_match_string() (Andy Shevchenko) >From V1 submission: The first patch in this series introduces a new resctrl file, "thread_throttle_mode", on Intel systems that exposes to the user how per-thread values are allocated to a core. This is added in support of newer Intel systems that can be configured to allocate either maximum or minimum throttling of the per-thread CLOS values to the core. Details about the feature can be found in the commit description and in Chapter 9 of the most recent Intel ISE available from https://software.intel.com/sites/default/files/managed/c5/15/architecture-instruction-set-extensions-programming-reference.pdf The first patch parses user input with the appropriate sysfs API that has not previously been used in resctrl. The second (later in the fourth) patch is added as a subsequent cleanup that switches existing resctrl string parsing code to also use this appropriate API. Fenghua Yu (2): x86/resctrl: Enumerate per-thread MBA x86/resctrl: Enable per-thread MBA Reinette Chatre (2): x86/resctrl: Enable user to view and select thread throttling mode x86/resctrl: Use appropriate API for strings terminated by newline Documentation/x86/resctrl_ui.rst | 22 ++- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/cpuid-deps.c | 1 + arch/x86/kernel/cpu/resctrl/core.c | 32 ++++ arch/x86/kernel/cpu/resctrl/internal.h | 13 ++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 231 +++++++++++++++++++++++-- arch/x86/kernel/cpu/scattered.c | 1 + 7 files changed, 283 insertions(+), 18 deletions(-) -- 2.21.0
