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 cpumask, nvdimm device pointer and pmu event functions like event_init/add/read/del. User could use the standard perf tool to access perf events exposed via pmu.
Interface also defines supported event list, config fields for the event attributes and their corresponding bit values which are exported via sysfs. Patch 3 exposes IBM pseries platform nmem* device performance stats using this interface. Result from power9 pseries lpar with 2 nvdimm device: Ex: List all event by perf list command:# perf list nmem nmem0/cache_rh_cnt/ [Kernel PMU event] nmem0/cache_wh_cnt/ [Kernel PMU event] nmem0/cri_res_util/ [Kernel PMU event] nmem0/ctl_res_cnt/ [Kernel PMU event] nmem0/ctl_res_tm/ [Kernel PMU event] nmem0/fast_w_cnt/ [Kernel PMU event] nmem0/host_l_cnt/ [Kernel PMU event] nmem0/host_l_dur/ [Kernel PMU event] nmem0/host_s_cnt/ [Kernel PMU event] nmem0/host_s_dur/ [Kernel PMU event] nmem0/med_r_cnt/ [Kernel PMU event] nmem0/med_r_dur/ [Kernel PMU event] nmem0/med_w_cnt/ [Kernel PMU event] nmem0/med_w_dur/ [Kernel PMU event] nmem0/mem_life/ [Kernel PMU event] nmem0/poweron_secs/ [Kernel PMU event] ... nmem1/mem_life/ [Kernel PMU event] nmem1/poweron_secs/ [Kernel PMU event] Patch1: Introduces the nvdimm_pmu structure Patch2: Adds common interface to add arch/platform specific data includes nvdimm device pointer, pmu data along with pmu event functions. It also defines supported event list and adds attribute groups for format, events and cpumask. 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 pmu name, capabilities, cpumask and event functions and then registers the pmu by adding callbacks to register_nvdimm_pmu. Patch4: Sysfs documentation patch Changelog --- Resend v5 -> v6 - No logic change, just a rebase to latest upstream and tested the patchset. - Link to the patchset Resend v5: https://lkml.org/lkml/2021/11/15/3979 v5 -> Resend v5 - Resend the patchset - Link to the patchset v5: https://lkml.org/lkml/2021/9/28/643 v4 -> v5: - Remove multiple variables defined in nvdimm_pmu structure include name and pmu functions(event_int/add/del/read) as they are just used to copy them again in pmu variable. Now we are directly doing this step in arch specific code as suggested by Dan Williams. - Remove attribute group field from nvdimm pmu structure and defined these attribute groups in common interface which includes format, event list along with cpumask as suggested by Dan Williams. Since we added static defination for attrbute groups needed in common interface, removes corresponding code from papr. - Add nvdimm pmu event list with event codes in the common interface. - Remove Acked-by/Reviewed-by/Tested-by tags as code is refactored to handle review comments from Dan. - Make nvdimm_pmu_free_hotplug_memory function static as reported by kernel test robot, also add corresponding Reported-by tag. - Link to the patchset v4: https://lkml.org/lkml/2021/9/3/45 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 docs: ABI: sysfs-bus-nvdimm: Document sysfs event format entries for nvdimm pmu Documentation/ABI/testing/sysfs-bus-nvdimm | 35 +++ arch/powerpc/include/asm/device.h | 5 + arch/powerpc/platforms/pseries/papr_scm.c | 225 ++++++++++++++ drivers/nvdimm/Makefile | 1 + drivers/nvdimm/nd_perf.c | 328 +++++++++++++++++++++ include/linux/nd.h | 41 +++ 6 files changed, 635 insertions(+) create mode 100644 drivers/nvdimm/nd_perf.c -- 2.31.1