perf-kvm(1)
===========
NAME
----
perf-kvm - Tool to trace/measure kvm guest os
SYNOPSIS
--------
[verse]
'perf kvm' [--host] [--guest] [--guestmount=<path>
[--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
{top|record|report|diff|buildid-list} [<options>]
'perf kvm' [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
| --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>]
'perf kvm stat [record|report|live] [<options>]
DESCRIPTION
-----------
There are a couple of variants of perf kvm:
'perf kvm [options] top <command>' to generates and displays
a performance counter profile of guest os in realtime
of an arbitrary workload.
'perf kvm record <command>' to record the performance counter profile
of an arbitrary workload and save it into a perf data file. We set the
default behavior of perf kvm as --guest, so if neither --host nor --guest
is input, the perf data file name is perf.data.guest. If --host is input,
the perf data file name is perf.data.kvm. If you want to record data into
perf.data.host, please input --host --no-guest. The behaviors are shown as
following:
Default('') -> perf.data.guest
--host -> perf.data.kvm
--guest -> perf.data.guest
--host --guest -> perf.data.kvm
--host --no-guest -> perf.data.host
'perf kvm report' to display the performance counter profile information
recorded via perf kvm record.
'perf kvm diff' to displays the performance difference amongst two perf.data
files captured via perf record.
'perf kvm buildid-list' to display the buildids found in a perf data file,
so that other tools can be used to fetch packages with matching symbol tables
for use by perf report. As buildid is read from /sys/kernel/notes in os, then
if you want to list the buildid for guest, please make sure your perf data file
was captured with --guestmount in perf kvm record.
'perf kvm stat <command>' to run a command and gather performance counter
statistics.
Especially, perf 'kvm stat record/report' generates a statistical analysis
of KVM events. Currently, vmexit, mmio (x86 only) and ioport (x86 only)
events are supported. 'perf kvm stat record <command>' records kvm events
and the events between start and end <command>.
And this command produces a file which contains tracing results of kvm
events.
'perf kvm stat report' reports statistical data which includes events
handled sample, percent_sample, time, percent_time, max_t, min_t, mean_t.
'perf kvm stat live' reports statistical data in a live mode (similar to
record + report but with statistical data updated live at a given display
rate).
OPTIONS
-------
-i::
--input=<path>::
Input file name, for the 'report', 'diff' and 'buildid-list' subcommands.
-o::
--output=<path>::
Output file name, for the 'record' subcommand. Doesn't work with 'report',
just redirect the output to a file when using 'report'.
--host::
Collect host side performance profile.
--guest::
Collect guest side performance profile.
:GMEXAMPLECMD: kvm --host --guest
:GMEXAMPLESUBCMD: top
include::guest-files.txt[]
--stdio:: Use the stdio interface.
-v::
--verbose::
Be more verbose (show counter open errors, etc).
STAT REPORT OPTIONS
-------------------
--vcpu=<value>::
analyze events which occur on this vcpu. (default: all vcpus)
--event=<value>::
event to be analyzed. Possible values: vmexit, mmio (x86 only),
ioport (x86 only). (default: vmexit)
-k::
--key=<value>::
Sorting key. Possible values: sample (default, sort by samples
number), percent_sample (sort by sample percentage), time
(sort by average time), precent_time (sort by time percentage),
max_t (sort by maximum time), min_t (sort by minimum time), mean_t
(sort by mean time).
-p::
--pid=::
Analyze events only for given process ID(s) (comma separated list).
STAT LIVE OPTIONS
-----------------
-d::
--display::
Time in seconds between display updates
-m::
--mmap-pages=::
Number of mmap data pages (must be a power of two) or size
specification in bytes with appended unit character - B/K/M/G.
The size is rounded up to the nearest power-of-two page value.
-a::
--all-cpus::
System-wide collection from all CPUs.
-p::
--pid=::
Analyze events only for given process ID(s) (comma separated list).
--vcpu=<value>::
analyze events which occur on this vcpu. (default: all vcpus)
--event=<value>::
event to be analyzed. Possible values: vmexit,
mmio (x86 only), ioport (x86 only).
(default: vmexit)
-k::
--key=<value>::
Sorting key. Possible values: sample (default, sort by samples
number), time (sort by average time).
--duration=<value>::
Show events other than HLT (x86 only) or Wait state (s390 only)
that take longer than duration usecs.
--proc-map-timeout::
When processing pre-existing threads /proc/XXX/mmap, it may take
a long time, because the file may be huge. A time out is needed
in such cases.
This option sets the time out limit. The default value is 500 ms.
SEE ALSO
--------
linkperf:perf-top[1], linkperf:perf-record[1], linkperf:perf-report[1],
linkperf:perf-diff[1], linkperf:perf-buildid-list[1],
linkperf:perf-stat[1]
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