xref: /linux/tools/perf/Documentation/perf-kvm.txt (revision 55d0969c451159cff86949b38c39171cab962069)
1perf-kvm(1)
2===========
3
4NAME
5----
6perf-kvm - Tool to trace/measure kvm guest os
7
8SYNOPSIS
9--------
10[verse]
11'perf kvm' [--host] [--guest] [--guestmount=<path>
12	[--guestkallsyms=<path> --guestmodules=<path> | --guestvmlinux=<path>]]
13	{top|record|report|diff|buildid-list} [<options>]
14'perf kvm' [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
15	| --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat} [<options>]
16'perf kvm stat [record|report|live] [<options>]
17
18DESCRIPTION
19-----------
20There are a couple of variants of perf kvm:
21
22  'perf kvm [options] top <command>' to generates and displays
23  a performance counter profile of guest os in realtime
24  of an arbitrary workload.
25
26  'perf kvm record <command>' to record the performance counter profile
27  of an arbitrary workload and save it into a perf data file. We set the
28  default behavior of perf kvm as --guest, so if neither --host nor --guest
29  is input, the perf data file name is perf.data.guest. If --host is input,
30  the perf data file name is perf.data.kvm. If you want to record data into
31  perf.data.host, please input --host --no-guest. The behaviors are shown as
32  following:
33    Default('')         ->  perf.data.guest
34    --host              ->  perf.data.kvm
35    --guest             ->  perf.data.guest
36    --host --guest      ->  perf.data.kvm
37    --host --no-guest   ->  perf.data.host
38
39  'perf kvm report' to display the performance counter profile information
40  recorded via perf kvm record.
41
42  'perf kvm diff' to displays the performance difference amongst two perf.data
43  files captured via perf record.
44
45  'perf kvm buildid-list' to  display the buildids found in a perf data file,
46  so that other tools can be used to fetch packages with matching symbol tables
47  for use by perf report. As buildid is read from /sys/kernel/notes in os, then
48  if you want to list the buildid for guest, please make sure your perf data file
49  was captured with --guestmount in perf kvm record.
50
51  'perf kvm stat <command>' to run a command and gather performance counter
52  statistics.
53  Especially, perf 'kvm stat record/report' generates a statistical analysis
54  of KVM events. Currently, vmexit, mmio (x86 only) and ioport (x86 only)
55  events are supported. 'perf kvm stat record <command>' records kvm events
56  and the events between start and end <command>.
57  And this command produces a file which contains tracing results of kvm
58  events.
59
60  'perf kvm stat report' reports statistical data which includes events
61  handled sample, percent_sample, time, percent_time, max_t, min_t, mean_t.
62
63  'perf kvm stat live' reports statistical data in a live mode (similar to
64  record + report but with statistical data updated live at a given display
65  rate).
66
67OPTIONS
68-------
69-i::
70--input=<path>::
71        Input file name, for the 'report', 'diff' and 'buildid-list' subcommands.
72-o::
73--output=<path>::
74        Output file name, for the 'record' subcommand. Doesn't work with 'report',
75        just redirect the output to a file when using 'report'.
76--host::
77        Collect host side performance profile.
78--guest::
79        Collect guest side performance profile.
80
81:GMEXAMPLECMD: kvm --host --guest
82:GMEXAMPLESUBCMD: top
83include::guest-files.txt[]
84
85--stdio:: Use the stdio interface.
86
87-v::
88--verbose::
89	Be more verbose (show counter open errors, etc).
90
91STAT REPORT OPTIONS
92-------------------
93--vcpu=<value>::
94       analyze events which occur on this vcpu. (default: all vcpus)
95
96--event=<value>::
97       event to be analyzed. Possible values: vmexit, mmio (x86 only),
98       ioport (x86 only). (default: vmexit)
99-k::
100--key=<value>::
101       Sorting key. Possible values: sample (default, sort by samples
102       number), percent_sample (sort by sample percentage), time
103       (sort by average time), precent_time (sort by time percentage),
104       max_t (sort by maximum time), min_t (sort by minimum time), mean_t
105       (sort by mean time).
106-p::
107--pid=::
108    Analyze events only for given process ID(s) (comma separated list).
109
110STAT LIVE OPTIONS
111-----------------
112-d::
113--display::
114        Time in seconds between display updates
115
116-m::
117--mmap-pages=::
118        Number of mmap data pages (must be a power of two) or size
119        specification in bytes with appended unit character - B/K/M/G.
120        The size is rounded up to the nearest power-of-two page value.
121
122-a::
123--all-cpus::
124        System-wide collection from all CPUs.
125
126-p::
127--pid=::
128    Analyze events only for given process ID(s) (comma separated list).
129
130--vcpu=<value>::
131       analyze events which occur on this vcpu. (default: all vcpus)
132
133
134--event=<value>::
135       event to be analyzed. Possible values: vmexit,
136       mmio (x86 only), ioport (x86 only).
137       (default: vmexit)
138
139-k::
140--key=<value>::
141       Sorting key. Possible values: sample (default, sort by samples
142       number), time (sort by average time).
143
144--duration=<value>::
145       Show events other than HLT (x86 only) or Wait state (s390 only)
146       that take longer than duration usecs.
147
148--proc-map-timeout::
149	When processing pre-existing threads /proc/XXX/mmap, it may take
150	a long time, because the file may be huge. A time out is needed
151	in such cases.
152	This option sets the time out limit. The default value is 500 ms.
153
154SEE ALSO
155--------
156linkperf:perf-top[1], linkperf:perf-record[1], linkperf:perf-report[1],
157linkperf:perf-diff[1], linkperf:perf-buildid-list[1],
158linkperf:perf-stat[1]
159