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ed78f56e12
In case performance stats for an nvdimm are not available, reading the
'perf_stats' sysfs file returns an -ENOENT error. A better approach is
to make the 'perf_stats' file entirely invisible to indicate that
performance stats for an nvdimm are unavailable.
So this patch updates 'papr_nd_attribute_group' to add a 'is_visible'
callback implemented as newly introduced 'papr_nd_attribute_visible()'
that returns an appropriate mode in case performance stats aren't
supported in a given nvdimm.
Also the initialization of 'papr_scm_priv.stat_buffer_len' is moved
from papr_scm_nvdimm_init() to papr_scm_probe() so that it value is
available when 'papr_nd_attribute_visible()' is called during nvdimm
initialization.
Even though 'perf_stats' attribute is available since v5.9, there are
no known user-space tools/scripts that are dependent on presence of its
sysfs file. Hence I dont expect any user-space breakage with this
patch.
Fixes: 2d02bf835e ("powerpc/papr_scm: Fetch nvdimm performance stats from PHYP")
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210513092349.285021-1-vaibhav@linux.ibm.com
63 lines
2.2 KiB
Text
63 lines
2.2 KiB
Text
What: /sys/bus/nd/devices/nmemX/papr/flags
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Date: Apr, 2020
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KernelVersion: v5.8
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Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, nvdimm@lists.linux.dev,
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Description:
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(RO) Report flags indicating various states of a
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papr-pmem NVDIMM device. Each flag maps to a one or
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more bits set in the dimm-health-bitmap retrieved in
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response to H_SCM_HEALTH hcall. The details of the bit
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flags returned in response to this hcall is available
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at 'Documentation/powerpc/papr_hcalls.rst' . Below are
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the flags reported in this sysfs file:
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* "not_armed"
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Indicates that NVDIMM contents will not
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survive a power cycle.
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* "flush_fail"
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Indicates that NVDIMM contents
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couldn't be flushed during last
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shut-down event.
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* "restore_fail"
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Indicates that NVDIMM contents
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couldn't be restored during NVDIMM
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initialization.
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* "encrypted"
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NVDIMM contents are encrypted.
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* "smart_notify"
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There is health event for the NVDIMM.
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* "scrubbed"
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Indicating that contents of the
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NVDIMM have been scrubbed.
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* "locked"
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Indicating that NVDIMM contents cant
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be modified until next power cycle.
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What: /sys/bus/nd/devices/nmemX/papr/perf_stats
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Date: May, 2020
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KernelVersion: v5.9
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Contact: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>, nvdimm@lists.linux.dev,
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Description:
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(RO) Report various performance stats related to papr-scm NVDIMM
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device. This attribute is only available for NVDIMM devices
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that support reporting NVDIMM performance stats. Each stat is
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reported on a new line with each line composed of a
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stat-identifier followed by it value. Below are currently known
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dimm performance stats which are reported:
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* "CtlResCt" : Controller Reset Count
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* "CtlResTm" : Controller Reset Elapsed Time
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* "PonSecs " : Power-on Seconds
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* "MemLife " : Life Remaining
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* "CritRscU" : Critical Resource Utilization
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* "HostLCnt" : Host Load Count
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* "HostSCnt" : Host Store Count
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* "HostSDur" : Host Store Duration
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* "HostLDur" : Host Load Duration
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* "MedRCnt " : Media Read Count
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* "MedWCnt " : Media Write Count
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* "MedRDur " : Media Read Duration
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* "MedWDur " : Media Write Duration
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* "CchRHCnt" : Cache Read Hit Count
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* "CchWHCnt" : Cache Write Hit Count
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* "FastWCnt" : Fast Write Count
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