tools/perf/Documentation/perf-kvm.txt

   1 perf-kvm(1)
   2 ===========
   3
   4 NAME
   5 ----
   6 perf-kvm - Tool to trace/measure kvm guest os
   7
   8 SYNOPSIS
   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
  18 DESCRIPTION
  19 -----------
  20 There 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 time, samples, and so on.
  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
  67 OPTIONS
  68 -------
  69 -i::
  70 --input=<path>::
  71         Input file name.
  72 -o::
  73 --output=<path>::
  74         Output file name.
  75 --host::
  76         Collect host side performance profile.
  77 --guest::
  78         Collect guest side performance profile.
  79 --guestmount=<path>::
  80         Guest os root file system mount directory. Users mounts guest os
  81         root directories under <path> by a specific filesystem access method,
  82         typically, sshfs. For example, start 2 guest os. The one's pid is 8888
  83         and the other's is 9999.
  84         #mkdir ~/guestmount; cd ~/guestmount
  85         #sshfs -o allow_other,direct_io -p 5551 localhost:/ 8888/
  86         #sshfs -o allow_other,direct_io -p 5552 localhost:/ 9999/
  87         #perf kvm --host --guest --guestmount=~/guestmount top
  88 --guestkallsyms=<path>::
  89         Guest os /proc/kallsyms file copy. 'perf' kvm' reads it to get guest
  90         kernel symbols. Users copy it out from guest os.
  91 --guestmodules=<path>::
  92         Guest os /proc/modules file copy. 'perf' kvm' reads it to get guest
  93         kernel module information. Users copy it out from guest os.
  94 --guestvmlinux=<path>::
  95         Guest os kernel vmlinux.
  96 -v::
  97 --verbose::
  98         Be more verbose (show counter open errors, etc).
  99
 100 STAT REPORT OPTIONS
 101 -------------------
 102 --vcpu=<value>::
 103        analyze events which occur on this vcpu. (default: all vcpus)
 104
 105 --event=<value>::
 106        event to be analyzed. Possible values: vmexit, mmio (x86 only),
 107        ioport (x86 only). (default: vmexit)
 108 -k::
 109 --key=<value>::
 110        Sorting key. Possible values: sample (default, sort by samples
 111        number), time (sort by average time).
 112 -p::
 113 --pid=::
 114     Analyze events only for given process ID(s) (comma separated list).
 115
 116 STAT LIVE OPTIONS
 117 -----------------
 118 -d::
 119 --display::
 120         Time in seconds between display updates
 121
 122 -m::
 123 --mmap-pages=::
 124     Number of mmap data pages (must be a power of two) or size
 125     specification with appended unit character - B/K/M/G. The
 126     size is rounded up to have nearest pages power of two value.
 127
 128 -a::
 129 --all-cpus::
 130         System-wide collection from all CPUs.
 131
 132 -p::
 133 --pid=::
 134     Analyze events only for given process ID(s) (comma separated list).
 135
 136 --vcpu=<value>::
 137        analyze events which occur on this vcpu. (default: all vcpus)
 138
 139
 140 --event=<value>::
 141        event to be analyzed. Possible values: vmexit,
 142        mmio (x86 only), ioport (x86 only).
 143        (default: vmexit)
 144
 145 -k::
 146 --key=<value>::
 147        Sorting key. Possible values: sample (default, sort by samples
 148        number), time (sort by average time).
 149
 150 --duration=<value>::
 151        Show events other than HLT (x86 only) or Wait state (s390 only)
 152        that take longer than duration usecs.
 153
 154 --proc-map-timeout::
 155         When processing pre-existing threads /proc/XXX/mmap, it may take
 156         a long time, because the file may be huge. A time out is needed
 157         in such cases.
 158         This option sets the time out limit. The default value is 500 ms.
 159
 160 SEE ALSO
 161 --------
 162 linkperf:perf-top[1], linkperf:perf-record[1], linkperf:perf-report[1],
 163 linkperf:perf-diff[1], linkperf:perf-buildid-list[1],
 164 linkperf:perf-stat[1]