linux/tools/perf/Documentation/perf-kvm.txt
Xiao Guangrong bcf6edcd6f perf kvm: Events analysis tool
Add 'perf kvm stat' support to analyze kvm vmexit/mmio/ioport smartly

Usage:
- kvm stat
  run a command and gather performance counter statistics, it is the alias of
  perf stat

- trace kvm events:
  perf kvm stat record, or, if other tracepoints are interesting as well, we
  can append the events like this:
  perf kvm stat record -e timer:* -a

  If many guests are running, we can track the specified guest by using -p or
  --pid, -a is used to track events generated by all guests.

- show the result:
  perf kvm stat report

The output example is following:
13005
13059

total 2 guests are running on the host

Then, track the guest whose pid is 13059:
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.253 MB perf.data.guest (~11065 samples) ]

See the vmexit events:

Analyze events for all VCPUs:

             VM-EXIT    Samples  Samples%     Time%         Avg time

         APIC_ACCESS        460    70.55%     0.01%     22.44us ( +-   1.75% )
                 HLT         93    14.26%    99.98% 832077.26us ( +-  10.42% )
  EXTERNAL_INTERRUPT         64     9.82%     0.00%     35.35us ( +-  14.21% )
   PENDING_INTERRUPT         24     3.68%     0.00%      9.29us ( +-  31.39% )
           CR_ACCESS          7     1.07%     0.00%      8.12us ( +-   5.76% )
      IO_INSTRUCTION          3     0.46%     0.00%     18.00us ( +-  11.79% )
       EXCEPTION_NMI          1     0.15%     0.00%      5.83us ( +-   -nan% )

Total Samples:652, Total events handled time:77396109.80us.

See the mmio events:

Analyze events for all VCPUs:

         MMIO Access    Samples  Samples%     Time%         Avg time

        0xfee00380:W        387    84.31%    79.28%      8.29us ( +-   3.32% )
        0xfee00300:W         24     5.23%     9.96%     16.79us ( +-   1.97% )
        0xfee00300:R         24     5.23%     7.83%     13.20us ( +-   3.00% )
        0xfee00310:W         24     5.23%     2.93%      4.94us ( +-   3.84% )

Total Samples:459, Total events handled time:4044.59us.

See the ioport event:

Analyze events for all VCPUs:

      IO Port Access    Samples  Samples%     Time%         Avg time

         0xc050:POUT          3   100.00%   100.00%     13.75us ( +-  10.83% )

Total Samples:3, Total events handled time:41.26us.

And, --vcpu is used to track the specified vcpu and --key is used to sort the
result:

Analyze events for VCPU 0:

             VM-EXIT    Samples  Samples%     Time%         Avg time

                 HLT         27    13.85%    99.97% 405790.24us ( +-  12.70% )
  EXTERNAL_INTERRUPT         13     6.67%     0.00%     27.94us ( +-  22.26% )
         APIC_ACCESS        146    74.87%     0.03%     21.69us ( +-   2.91% )
      IO_INSTRUCTION          2     1.03%     0.00%     17.77us ( +-  20.56% )
           CR_ACCESS          2     1.03%     0.00%      8.55us ( +-   6.47% )
   PENDING_INTERRUPT          5     2.56%     0.00%      6.27us ( +-   3.94% )

Total Samples:195, Total events handled time:10959950.90us.

Signed-off-by: Dong Hao <haodong@linux.vnet.ibm.com>
Signed-off-by: Runzhen Wang <runzhen@linux.vnet.ibm.com>
[ Dong Hao <haodong@linux.vnet.ibm.com>
  Runzhen Wang <runzhen@linux.vnet.ibm.com>:
     - rebase it on current acme's tree
     - fix the compiling-error on i386 ]
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Runzhen Wang <runzhen@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1347870675-31495-4-git-send-email-haodong@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2012-09-21 12:51:22 -03:00

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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}
'perf kvm' [--host] [--guest] [--guestkallsyms=<path> --guestmodules=<path>
| --guestvmlinux=<path>] {top|record|report|diff|buildid-list|stat}
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. If both
--host and --guest are input, the perf data file name is perf.data.kvm.
If there is no --host but --guest, the file name is perf.data.guest.
If there is no --guest but --host, the file name is 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.
'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.
OPTIONS
-------
-i::
--input=::
Input file name.
-o::
--output::
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.
STAT REPORT OPTIONS
-------------------
--vcpu=<value>::
analyze events which occures on this vcpu. (default: all vcpus)
--events=<value>::
events 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).
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]