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| author | Vaibhav Jain <vaibhav@linux.ibm.com> | 2020-07-31 08:41:52 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-07-31 14:55:27 +0200 |
| commit | 2d02bf835e5731de632c8a13567905fa7c0da01c (patch) | |
| tree | dcf4f379102e0f71d3c4b18b5300fb64850a601b /Documentation/ABI | |
| parent | cpuidle: pseries: Fixup exit latency for CEDE(0) (diff) | |
| download | linux-2d02bf835e5731de632c8a13567905fa7c0da01c.tar.xz linux-2d02bf835e5731de632c8a13567905fa7c0da01c.zip | |
powerpc/papr_scm: Fetch nvdimm performance stats from PHYP
Update papr_scm.c to query dimm performance statistics from PHYP via
H_SCM_PERFORMANCE_STATS hcall and export them to user-space as PAPR
specific NVDIMM attribute 'perf_stats' in sysfs. The patch also
provide a sysfs ABI documentation for the stats being reported and
their meanings.
During NVDIMM probe time in papr_scm_nvdimm_init() a special variant
of H_SCM_PERFORMANCE_STATS hcall is issued to check if collection of
performance statistics is supported or not. If successful then a PHYP
returns a maximum possible buffer length needed to read all
performance stats. This returned value is stored in a per-nvdimm
attribute 'stat_buffer_len'.
The layout of request buffer for reading NVDIMM performance stats from
PHYP is defined in 'struct papr_scm_perf_stats' and 'struct
papr_scm_perf_stat'. These structs are used in newly introduced
drc_pmem_query_stats() that issues the H_SCM_PERFORMANCE_STATS hcall.
The sysfs access function perf_stats_show() uses value
'stat_buffer_len' to allocate a buffer large enough to hold all
possible NVDIMM performance stats and passes it to
drc_pmem_query_stats() to populate. Finally statistics reported in the
buffer are formatted into the sysfs access function output buffer.
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200731064153.182203-2-vaibhav@linux.ibm.com
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-papr-pmem | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-papr-pmem b/Documentation/ABI/testing/sysfs-bus-papr-pmem index 5b10d036a8d4..c1a67275c43f 100644 --- a/Documentation/ABI/testing/sysfs-bus-papr-pmem +++ b/Documentation/ABI/testing/sysfs-bus-papr-pmem @@ -25,3 +25,30 @@ Description: NVDIMM have been scrubbed. * "locked" : Indicating that NVDIMM contents cant be modified until next power cycle. + +What: /sys/bus/nd/devices/nmemX/papr/perf_stats +Date: May, 2020 +KernelVersion: v5.9 +Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, linux-nvdimm@lists.01.org, +Description: + (RO) Report various performance stats related to papr-scm NVDIMM + device. Each stat is reported on a new line with each line + composed of a stat-identifier followed by it value. Below are + currently known dimm performance stats which are reported: + + * "CtlResCt" : Controller Reset Count + * "CtlResTm" : Controller Reset Elapsed Time + * "PonSecs " : Power-on Seconds + * "MemLife " : Life Remaining + * "CritRscU" : Critical Resource Utilization + * "HostLCnt" : Host Load Count + * "HostSCnt" : Host Store Count + * "HostSDur" : Host Store Duration + * "HostLDur" : Host Load Duration + * "MedRCnt " : Media Read Count + * "MedWCnt " : Media Write Count + * "MedRDur " : Media Read Duration + * "MedWDur " : Media Write Duration + * "CchRHCnt" : Cache Read Hit Count + * "CchWHCnt" : Cache Write Hit Count + * "FastWCnt" : Fast Write Count
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