On 2/25/22 11:25, Nageswara Sastry wrote:

quoted

On 17/02/22 10:03 pm, Kajol Jain wrote:

quoted

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

Tested these patches with the automated tests at
avocado-misc-tests/perf/perf_nmem.py
URL:
https://github.com/avocado-framework-tests/avocado-misc-tests/blob/master/perf/perf_nmem.py


1. On the system where target id and online id were different then not
seeing value in 'cpumask' and those tests failed.

Example:
Log from dmesg
...
papr_scm ibm,persistent-memory:ibm,pmemory@44100003: Region registered
with target node 1 and online node 0
...

Hi Nageswara Sastry,
        Thanks for testing the patch set. Yes you right, incase target
node id and online node id is different, it can happen when target
node is not online and hence can cause this issue, thanks for pointing
it.

Function dev_to_node will return node id for a given nvdimm device which
can be offline in some scenarios. We should use numa node id return by
numa_map_to_online_node function in that scenario. This function incase
given node is offline, it will lookup for next closest online node and
return that nodeid.

Can you try with below change and see, if you are still getting this
issue. Please let me know.

diff --git a/arch/powerpc/platforms/pseries/papr_scm.c

b/arch/powerpc/platforms/pseries/papr_scm.c
index bdf2620db461..4dd513d7c029 100644

--- a/arch/powerpc/platforms/pseries/papr_scm.c
+++ b/arch/powerpc/platforms/pseries/papr_scm.c

@@ -536,7 +536,7 @@ static void papr_scm_pmu_register(struct

papr_scm_priv *p)
                                 PERF_PMU_CAP_NO_EXCLUDE;

         /*updating the cpumask variable */
-       nodeid = dev_to_node(&p->pdev->dev);
+       nodeid = numa_map_to_online_node(dev_to_node(&p->pdev->dev));
         nd_pmu->arch_cpumask = *cpumask_of_node(nodeid);

Thanks,
Kajol Jain