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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | STAT REPORT OPTIONS | STAT LIVE OPTIONS | SEE ALSO | COLOPHON |
PERF-KVM(1) perf Manual PERF-KVM(1)
perf-kvm - Tool to trace/measure kvm guest os
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>]
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 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).
-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).
--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).
-p, --pid=
Analyze events only for given process ID(s) (comma separated
list).
-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 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.
perf-top(1), perf-record(1), perf-report(1), perf-diff(1),
perf-buildid-list(1), perf-stat(1)
This page is part of the perf (Performance analysis tools for Linux
(in Linux source tree)) project. Information about the project can
be found at ⟨https://perf.wiki.kernel.org/index.php/Main_Page⟩. If
you have a bug report for this manual page, send it to
linux-kernel@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git⟩ on
2017-07-05. If you discover any rendering problems in this HTML ver‐
sion of the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original man‐
ual page), send a mail to man-pages@man7.org
perf 02/18/2017 PERF-KVM(1)