linux-stable.git/tools/perf/Documentation/perf-diff.txt, branch linux-5.4.y

perf diff: Documentation -c cycles option

2019-07-02T16:20:51+00:00

Documentation the new computation selection 'cycles'.

 v4:
 ---
 Change the column 'Block cycles diff [start:end]' to
 '[Program Block Range] Cycles Diff'

Signed-off-by: Jin Yao 
Reviewed-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1561713784-30533-8-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf time-utils: Add support for multiple explicit time intervals

2019-06-10T19:20:13+00:00

Currently only a single explicit time range is accepted. Add support for
multiple ranges separated by spaces, which requires the string to be
quoted. Update the time utils test accordingly.

Signed-off-by: Adrian Hunter 
Cc: Jin Yao 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/20190604130017.31207-20-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf time-utils: Fix --time documentation

2019-06-10T19:20:12+00:00

Correct some punctuation and spelling and correct the format to show
that the time resolution is nanoseconds not microseconds.

Signed-off-by: Adrian Hunter 
Cc: Jin Yao 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/20190604130017.31207-16-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --pid/--tid filter options

2019-03-06T21:06:16+00:00

Using the existing symbol_conf.pid_list_str and symbol_conf.tid_list_str
logic.

For example:

  perf diff --tid 13965

It'll only diff the samples for thread 13965.

Signed-off-by: Jin Yao 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1551791143-10334-4-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --cpu filter option

2019-03-06T21:05:21+00:00

To improve 'perf diff', implement a --cpu filter option.

Multiple CPUs can be provided as a comma-separated list with no space:
0,1.  Ranges of CPUs are specified with -: 0-2. Default is to report
samples on all CPUs.

For example,

  perf diff --cpu 0,1

It only diff the samples for CPU0 and CPU1.

Signed-off-by: Jin Yao 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1551791143-10334-3-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Support --time filter option

2019-03-06T21:03:23+00:00

To improve 'perf diff', implement a --time filter option to diff the
samples within given time window.

It supports time percent with multiple time ranges. The time string
format is 'a%/n,b%/m,...' or 'a%-b%,c%-%d,...'.

For example:

Select the second 10% time slice to diff:

  perf diff --time 10%/2

Select from 0% to 10% time slice to diff:

  perf diff --time 0%-10%

Select the first and the second 10% time slices to diff:

  perf diff --time 10%/1,10%/2

Select from 0% to 10% and 30% to 40% slices to diff:

  perf diff --time 0%-10%,30%-40%

It also supports analysing samples within a given time window
,.

Times have the format seconds.microseconds.

If 'start' is not given (i.e., time string is ',x.y') then analysis starts at
the beginning of the file.

If the stop time is not given (i.e, time string is 'x.y,') then analysis
goes to end of file.

Time string is 'a1.b1,c1.d1:a2.b2,c2.d2'. Use ':' to separate timestamps for
different perf.data files.

For example, we get the timestamp information from perf script.

  perf script -i perf.data.old

    mgen 13940 [000]  3946.361400: ...

  perf script -i perf.data

    mgen 13940 [000]  3971.150589 ...

  perf diff --time 3946.361400,:3971.150589,

It analyzes the perf.data.old from the timestamp 3946.361400 to the end of
perf.data.old and analyzes the perf.data from the timestamp 3971.150589 to the
end of perf.data.

 v4:
 ---
 Update abstime_str_dup(), let it return error if strdup
 is failed, and update __cmd_diff() accordingly.

Signed-off-by: Jin Yao 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1551791143-10334-2-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add -q/--quiet option

2017-02-20T14:47:08+00:00

The -q/--quiet option is to suppress any message.  Sometimes users just
want to see the numbers and it can be used for that case.

Committer notes:

Before:

  # perf diff | head -10
  Failed to open /tmp/perf-6678.map, continuing without symbols
  Failed to open /tmp/perf-6678.map, continuing without symbols
  Failed to open /tmp/perf-2646.map, continuing without symbols
  # Event 'cycles'
  #
  # Baseline  Delta Abs  Shared Object               Symbol
  # ........  .........  ..........................  ............................................
  #
       5.36%     -1.76%  [kernel.vmlinux]            [k] intel_idle
       2.80%     +1.48%  firefox                     [.] 0x00000000000101fe
      57.12%     -1.25%  libxul.so                   [.] 0x00000000009bea92
       1.36%     -1.11%  [kernel.vmlinux]            [k] __schedule
       4.26%     -1.00%  perf-6678.map               [.] 0x00007fac4b0e9320

After:

  # perf diff -q | head -10
       5.36%     -1.76%  [kernel.vmlinux]            [k] intel_idle
       2.80%     +1.48%  firefox                     [.] 0x00000000000101fe
      57.12%     -1.25%  libxul.so                   [.] 0x00000000009bea92
       1.36%     -1.11%  [kernel.vmlinux]            [k] __schedule
       4.26%     -1.00%  perf-6678.map               [.] 0x00007fac4b0e9320
       1.86%     +0.95%  [kernel.vmlinux]            [k] update_blocked_averages
       0.80%     -0.70%  [kernel.vmlinux]            [k] native_sched_clock
       0.74%     -0.58%  [kernel.vmlinux]            [k] native_write_msr
       0.76%     -0.56%  qemu-system-x86_64          [.] 0x00000000002395c0
                 +0.54%  libpulsecommon-10.0.so      [.] 0x000000000002d91b
  #

Signed-off-by: Namhyung Kim 
Suggested-and-Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170217081742.17417-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Change default setting to "delta-abs"

2017-02-13T17:29:38+00:00

The "delta-abs" compute method will show most changed entries on top.
So users can easily see how much effect between the data.  Note that it
also changes the default of -o option to 1 in order to apply the compute
method.  To see original-style (sorted by baseline) use -o 0 option.

Signed-off-by: Namhyung Kim 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20170210161856.18422-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add diff.compute config option

2017-02-13T17:29:37+00:00

The diff.compute config variable is to set the default compute method of
perf diff command (-c option).  Possible values 'delta' (default),
'delta-abs', 'ratio' and 'wdiff'.

Signed-off-by: Namhyung Kim 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Taeung Song 
Link: http://lkml.kernel.org/r/20170210073614.24584-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Add diff.order config option

2017-02-13T17:29:37+00:00

In many cases, I need to look at differences between two data so I often
used the -o option to sort the result base on the difference first.
It'd be nice to have a config option to set it by default.

The diff.order config option is to set the default value of -o/--order
option.

Signed-off-by: Namhyung Kim 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Taeung Song 
Link: http://lkml.kernel.org/r/20170210073614.24584-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo