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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | STAT REPORT OPTIONS | STAT LIVE OPTIONS | SEE ALSO | COLOPHON |
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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 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).
-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.
--guestmount=<path>
Guest OS root file system mount directory. Users mount guest
OS root directories under <path> by a specific filesystem
access method, typically, sshfs. For example, start 2 guest
OS, 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 reads it to get guest
kernel symbols. Users copy it out from guest OS.
--guestmodules=<path>
Guest OS /proc/modules file copy. perf reads it to get guest
kernel module information. Users copy it out from guest OS.
--guestvmlinux=<path>
Guest OS kernel vmlinux.
--guest-code
Indicate that guest code can be found in the hypervisor
process, which is a common case for KVM test programs.
--stdio
Use the stdio interface.
-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), 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).
-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
[email protected]. This page was obtained from the
project's upstream Git repository
⟨http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git⟩
on 2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-13.) If you
discover any rendering problems in this HTML version 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
manual page), send a mail to [email protected]
perf 2023-03-15 PERF-KVM(1)
Pages that refer to this page: perf(1)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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