linux-toradex.git/tools/perf/Documentation, branch v3.7.4

perf trace: New tool

2012-09-26T23:42:23+00:00

Initially should look loosely like the venerable 'strace' tool, but
using the infrastructure in the perf tools to allow tracing extra
targets:

  [acme@sandy linux]$ perf trace --hell
  Error: unknown option `hell'

   usage: perf trace 

      -p, --pid        trace events on existing process id
          --tid        trace events on existing thread id
          --all-cpus        system-wide collection from all CPUs
          --cpu        list of cpus to monitor
          --no-inherit      child tasks do not inherit counters
          --mmap-pages   number of mmap data pages
          --uid       user to profile

  [acme@sandy linux]$

Those should have the same semantics as when using with 'perf record'.

It gets stuck sometimes, but hey, it works sometimes too!

In time it should support perf.data based workloads, i.e. it should have
a:
	-o filename

Command line option that will produce a perf.data file that can then be
used with 'perf trace' or any of the other perf tools (script, report,
etc).

It will also eventually have the set of functionalities described in the
previous 'trace' prototype by Thomas Gleixner:

   "Announcing a new utility: 'trace'"
   http://lwn.net/Articles/415728/

Also planned is to have some of the features suggested in the comments
of that LWN article.

Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Mike Galbraith 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Steven Rostedt 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/n/tip-v9x3q9rv4caxtox7wtjpchq5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf kvm: Events analysis tool

2012-09-21T15:51:22+00:00

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 
Signed-off-by: Runzhen Wang 
[ Dong Hao 
  Runzhen Wang :
     - rebase it on current acme's tree
     - fix the compiling-error on i386 ]
Signed-off-by: Xiao Guangrong 
Acked-by: David Ahern 
Cc: Avi Kivity 
Cc: David Ahern 
Cc: Ingo Molnar 
Cc: Marcelo Tosatti 
Cc: kvm@vger.kernel.org
Cc: Runzhen Wang 
Link: http://lkml.kernel.org/r/1347870675-31495-4-git-send-email-haodong@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Make diff command work with evsel hists

2012-09-08T00:44:02+00:00

Putting 'perf diff' command back on track with the 'latest'
evsel hists changes. Each evsel has its own 'hists' object
gathering stats for the particular event.

While currently counts are accumulated for the whole session
regardless of the events diversification within compared
sessions.

The 'perf diff' command now outputs all matching events within
compared sessions (with event name specified). The per event
diff output stays the same.

  $ ./perf diff
  # Event 'cycles'
  #
  # Baseline  Delta          Shared Object                          Symbol
  # ........ ..........  .................  ..............................
  #
       0.00%    +15.14%  [kernel.kallsyms]  [k] __wake_up
       0.00%    +13.38%  [kernel.kallsyms]  [k] ext4fs_dirhash

... SNIP

       0.00%     +0.42%  [kernel.kallsyms]  [k] local_clock
       0.17%     -0.05%  [kernel.kallsyms]  [k] native_write_msr_safe

  # Event 'faults'
  #
  # Baseline  Delta          Shared Object                          Symbol
  # ........ ..........  .................  ..............................
  #
       0.00%    +79.12%  ld-2.15.so         [.] _dl_relocate_object
       0.00%    +11.62%  ld-2.15.so         [.] openaux

Signed-off-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Corey Ashford 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Namhyung Kim 
Cc: Paul E. McKenney 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1346946426-13496-2-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow user to indicate path to objdump in command line

2012-09-05T22:41:55+00:00

When analyzing perf data from hosts of other architecture than one of
the local host it's useful to call objdump that is part of a toolchain
for that architecture. Instead of calling regular objdump, call one that
user specified in command line.

Signed-off-by: Maciek Borzecki 
Acked-by: David Ahern 
Link: http://lkml.kernel.org/r/1346754750.16299.3.camel@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo

perf script perl/python: Fix libexec scripts path in Documentation

2012-08-20T12:30:36+00:00

The libexec path is /libexec/perf-core/scripts/*/Perf-Trace-Util.

Signed-off-by: David Ahern 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/1345391182-71825-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Add description of JIT interface

2012-08-13T17:55:02+00:00

Add a description of the JIT interface in the perf symbol resolution
code. I reverse engineered the format from the source.

Signed-off-by: Andi Kleen 
Acked-by: Pekka Enberg 
Cc: Pekka Enberg 
Link: http://lkml.kernel.org/r/1344526260-18721-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo

perf list: Document precise event sampling for AMD IBS

2012-08-08T15:42:21+00:00

Updating man perf-list.

Signed-off-by: Robert Richter 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/1344361396-7237-7-git-send-email-robert.richter@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf list: Update documentation about raw event setup

2012-08-08T15:41:53+00:00

It was missing that only certain bit fields are passed to the config
value which confused users. Updating it.

Signed-off-by: Robert Richter 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/1344361396-7237-6-git-send-email-robert.richter@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix version file for perf documentation with OUTPUT variable set

2012-08-08T15:36:49+00:00

Fixes the following:

 + make OUTPUT=/.../.build/perf-user/ DESTDIR=/.../.install/perf-user/ man install-man
 make -C Documentation man
 make[1]: Entering directory `/.../.source/linux.perf/tools/perf/Documentation'
 make[2]: Entering directory `/.../.source/linux.perf/tools/perf'
 make[2]: *** No rule to make target `PERF-VERSION-FILE'.  Stop.

Signed-off-by: Robert Richter 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/1344361396-7237-2-git-send-email-robert.richter@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf bench: Fix confused variable namings and descriptions in mem subsystem

2012-07-02T17:35:45+00:00

As Namhyung Kim pointed, there are confused namings and descriptions of words
"cycle" and "clock" in mem-memset.c and mem-memcpy.c.

With the option "-c" (or "--clock", now renamed as "--cycle"), mem subsystem
measures cost of memset() and memcpy() with cpu-cycles event.

But current mem subsystem source code contains lots of confused variable
namings and descriptions with "clock" (e.g. the variable use_clock). This is a
very bad style because there is another software event named "cpu-clock". This
patch replaces wrong usage of "clock" to "cycle".

v2: modified Documentation/perf-bench.txt for the descriptions of
--cycle option

Signed-off-by: Hitoshi Mitake 
Cc: Ingo Molnar 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/1341236777-18457-1-git-send-email-h.mitake@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo