perf-kvm.txt
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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 and ioport 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 time, samples, and so on.
'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.
-o::
--output=<path>::
Output file name.
--host::
Collect host side performance profile.
--guest::
Collect guest side performance profile.
--guestmount=<path>::
Guest os root file system mount directory. Users mounts guest os
root directories under <path> by a specific filesystem access method,
typically, sshfs. For example, start 2 guest os. The one's pid is 8888
and the other's is 9999.
#mkdir ~/guestmount; cd ~/guestmount
#sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/
#sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/
#perf kvm --host --guest --guestmount=~/guestmount top
--guestkallsyms=<path>::
Guest os /proc/kallsyms file copy. 'perf' kvm' reads it to get guest
kernel symbols. Users copy it out from guest os.
--guestmodules=<path>::
Guest os /proc/modules file copy. 'perf' kvm' reads it to get guest
kernel module information. Users copy it out from guest os.
--guestvmlinux=<path>::
Guest os kernel vmlinux.
-v::
--verbose::
Be more verbose (show counter open errors, etc).
STAT REPORT OPTIONS
-------------------
--vcpu=<value>::
analyze events which occures on this vcpu. (default: all vcpus)
--event=<value>::
event to be analyzed. Possible values: vmexit, mmio, ioport.
(default: vmexit)
-k::
--key=<value>::
Sorting key. Possible values: sample (default, sort by samples
number), time (sort by average 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 with appended unit character - B/K/M/G. The
size is rounded up to have nearest pages power of two 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 occures on this vcpu. (default: all vcpus)
--event=<value>::
event to be analyzed. Possible values: vmexit, mmio, ioport.
(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 that take longer than duration usecs.
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]