Patchset adds performance stats reporting support for nvdimm. Added interface includes support for pmu register/unregister functions. A structure is added called nvdimm_pmu to be used for adding arch/platform specific data such as supported events, cpumask pmu event functions like event_init/add/read/del. User could use the standard perf tool to access perf events exposed via pmu.
Added implementation to expose IBM pseries platform nmem* device performance stats using this interface. Result from power9 pseries lpar with 2 nvdimm device: command:# perf list nmem nmem0/cchrhcnt/ [Kernel PMU event] nmem0/cchwhcnt/ [Kernel PMU event] nmem0/critrscu/ [Kernel PMU event] nmem0/ctlresct/ [Kernel PMU event] nmem0/ctlrestm/ [Kernel PMU event] nmem0/fastwcnt/ [Kernel PMU event] nmem0/hostlcnt/ [Kernel PMU event] nmem0/hostldur/ [Kernel PMU event] nmem0/hostscnt/ [Kernel PMU event] nmem0/hostsdur/ [Kernel PMU event] nmem0/medrcnt/ [Kernel PMU event] nmem0/medrdur/ [Kernel PMU event] nmem0/medwcnt/ [Kernel PMU event] nmem0/medwdur/ [Kernel PMU event] nmem0/memlife/ [Kernel PMU event] nmem0/noopstat/ [Kernel PMU event] nmem0/ponsecs/ [Kernel PMU event] nmem1/cchrhcnt/ [Kernel PMU event] nmem1/cchwhcnt/ [Kernel PMU event] nmem1/critrscu/ [Kernel PMU event] ... nmem1/noopstat/ [Kernel PMU event] nmem1/ponsecs/ [Kernel PMU event] Patch1: Introduces the nvdimm_pmu structure Patch2: Adds common interface to add arch/platform specific data includes supported events, pmu event functions. It also adds code for cpu hotplug support. Patch3: Add code in arch/powerpc/platform/pseries/papr_scm.c to expose nmem* pmu. It fills in the nvdimm_pmu structure with event attrs cpumask andevent functions and then registers the pmu by adding callbacks to register_nvdimm_pmu. Patch4: Sysfs documentation patch Changelog --- v3 -> v4 - Rebase code on top of current papr_scm code without any logical changes. - Added Acked-by tag from Peter Zijlstra and Reviewed by tag from Madhavan Srinivasan. - Link to the patchset v3: https://lkml.org/lkml/2021/6/17/605 v2 -> v3 - Added Tested-by tag. - Fix nvdimm mailing list in the ABI Documentation. - Link to the patchset v2: https://lkml.org/lkml/2021/6/14/25 v1 -> v2 - Fix hotplug code by adding pmu migration call incase current designated cpu got offline. As pointed by Peter Zijlstra. - Removed the retun -1 part from cpu hotplug offline function. - Link to the patchset v1: https://lkml.org/lkml/2021/6/8/500 Kajol Jain (4): drivers/nvdimm: Add nvdimm pmu structure drivers/nvdimm: Add perf interface to expose nvdimm performance stats powerpc/papr_scm: Add perf interface support powerpc/papr_scm: Document papr_scm sysfs event format entries Documentation/ABI/testing/sysfs-bus-papr-pmem | 31 ++ arch/powerpc/include/asm/device.h | 5 + arch/powerpc/platforms/pseries/papr_scm.c | 365 ++++++++++++++++++ drivers/nvdimm/Makefile | 1 + drivers/nvdimm/nd_perf.c | 230 +++++++++++ include/linux/nd.h | 46 +++ 6 files changed, 678 insertions(+) create mode 100644 drivers/nvdimm/nd_perf.c -- 2.26.2