linux-stable.git/tools/perf/util/scripting-engines, branch linux-4.7.y

perf tools: Fix usage of max_stack sysctl

2016-05-20T14:43:56+00:00

We cannot limit processing stacks from the current value of the sysctl,
as we may be processing perf.data files, possibly from other machines.

Instead use the old PERF_MAX_STACK_DEPTH, the sysctl default, that can
be overriden using --max-stack or equivalent.

Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Brendan Gregg 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: He Kuang 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Milian Wolff 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Cc: Wang Nan 
Cc: Zefan Li 
Fixes: 4cb93446c587 ("perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack")
Link: http://lkml.kernel.org/n/tip-eqeutsr7n7wy0c36z24ytvii@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use SBUILD_ID_SIZE where applicable

2016-05-11T16:06:06+00:00

Use the existing SBUILD_ID_SIZE macro instead of the equivalent
BUILD_ID_SIZE * 2 + 1 expression for allocating a buffer for build-id
strings.

Signed-off-by: Masami Hiramatsu 
Cc: Ananth N Mavinakayanahalli 
Cc: Brendan Gregg 
Cc: Hemant Kumar 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20160511135159.23943.57120.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo

perf scripting python: Use Py_FatalError instead of die()

2016-05-11T15:24:57+00:00

It probably is equivalent, but that seems to be the "pythonic" way of
dieing? Anyway, one less die() in the tools/perf codebase.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Cc: Chris Phlipot 
Link: http://lkml.kernel.org/n/tip-nlzgepdv2818zs4e7faif9tu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Fix incorrect python db-export error message

2016-05-09T17:08:39+00:00

Fix the error message printed when attempting and failing to create the
call path root incorrectly references the call return process.

This change fixes the message to properly reference the failure to
create the call path root.

Signed-off-by: Chris Phlipot 
Cc: Adrian Hunter 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1462612620-25008-2-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Expose usage of the callchain db export via the python api

2016-05-06T16:00:54+00:00

This change allows python scripts to be able to utilize the recent
changes to the db export api allowing the export of call_paths derived
from sampled callchains. These call paths are also now associated with
the samples from which they were derived.

- This feature is enabled by setting "perf_db_export_callchains" to true

- When enabled, samples that have callchain information will have the
  callchains exported via call_path_table

- The call_path_id field is added to sample_table to enable association of
  samples with the corresponding callchain stored in the call paths
  table. A call_path_id of 0 will be exported if there is no
  corresponding callchain.

- When "perf_db_export_callchains" and "perf_db_export_calls" are both
  set to True, the call path root data structure will be shared. This
  prevents duplicating of data and call path ids that would result from
  building two separate call path trees in memory.

- The call_return_processor structure definition was relocated to the header
  file to make its contents visible to db-export.c. This enables the
  sharing of call path trees between the two features, as mentioned
  above.

This change is visible to python scripts using the python db export api.

The change is backwards compatible with scripts written against the
previous API, assuming that the scripts model the sample_table function
after the one in export-to-postgresql.py script by allowing for
additional arguments to be added in the future. ie. using *x as the
final argument of the sample_table function.

Signed-off-by: Chris Phlipot 
Acked-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1461831551-12213-6-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Refactor code to move call path handling out of thread-stack

2016-05-06T16:00:43+00:00

Move the call path handling code out of thread-stack.c and
thread-stack.h to allow other components that are not part of
thread-stack to create call paths.

Summary:

- Create call-path.c and call-path.h and add them to the build.

- Move all call path related code out of thread-stack.c and thread-stack.h
  and into call-path.c and call-path.h.

- A small subset of structures and functions are now visible through
  call-path.h, which is required for thread-stack.c to continue to
  compile.

This change is a prerequisite for subsequent patches in this change set
and by itself contains no user-visible changes.

Signed-off-by: Chris Phlipot 
Acked-by: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1461831551-12213-3-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack

2016-04-27T13:29:07+00:00

There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter 
Cc: Brendan Gregg 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Milian Wolff 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Start moving away from global per thread cursors

2016-04-14T17:48:07+00:00

The recent perf_evsel__fprintf_callchain() move to evsel.c added several
new symbol requirements to the python binding, for instance:

  # perf test -v python
  16: Try 'import perf' in python, checking link problems      :
  --- start ---
  test child forked, pid 18030
  Traceback (most recent call last):
    File "", line 1, in 
  ImportError: /tmp/build/perf/python/perf.so: undefined symbol:
  callchain_cursor
  test child finished with -1
  ---- end ----
  Try 'import perf' in python, checking link problems: FAILED!
  #

This would require linking against callchain.c to access to the global
callchain_cursor variables.

Since lots of functions already receive as a parameter a
callchain_cursor struct pointer, make that be the case for some more
function so that we can start phasing out usage of yet another global
variable.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-djko3097eyg2rn66v2qcqfvn@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf script perl: Do error checking on new backtrace routine

2016-04-06T13:44:28+00:00

This ended up triggering these warnings when building on Ubuntu 12.04.5:

  util/scripting-engines/trace-event-perl.c: In function 'perl_process_callchain':
  util/scripting-engines/trace-event-perl.c:293:4: error: value computed is not used [-Werror=unused-value]
  util/scripting-engines/trace-event-perl.c:294:4: error: value computed is not used [-Werror=unused-value]
  util/scripting-engines/trace-event-perl.c:295:4: error: value computed is not used [-Werror=unused-value]
  util/scripting-engines/trace-event-perl.c:297:4: error: value computed is not used [-Werror=unused-value]
  util/scripting-engines/trace-event-perl.c:309:4: error: value computed is not used [-Werror=unused-value]
  cc1: all warnings being treated as errors
  mv: cannot stat `/tmp/build/perf/util/scripting-engines/.trace-event-perl.o.tmp': No such file or directory
  make[4]: *** [/tmp/build/perf/util/scripting-engines/trace-event-perl.o] Error 1

Fix it by doing error checking when building the perl data structures
related to callchains.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Dima Kogan 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Fixes: f7380c12ec6c ("perf script perl: Perl scripts now get a backtrace, like the python ones")
Signed-off-by: Arnaldo Carvalho de Melo

perf script perl: Perl scripts now get a backtrace, like the python ones

2016-03-30T14:14:09+00:00

We have some infrastructure to use perl or python to analyze logs
generated by perf.  Prior to this patch, only the python tools had
access to backtrace information.  This patch makes this information
available to perl scripts as well.  Example:

  Let's look at malloc() calls made by the seq utility.  First we
  create a probe point:

      $ perf probe -x /lib/x86_64-linux-gnu/libc.so.6 malloc
      Added new events:
      ...

  Now we run seq, while monitoring malloc() calls with perf

      $ perf record --call-graph=dwarf -e probe_libc:malloc seq 5
      1
      2
      3
      4
      5
      [ perf record: Woken up 1 times to write data ]
      [ perf record: Captured and wrote 0.064 MB perf.data (6 samples) ]

  We can use perf to look at its log to see the malloc calls and the backtrace

      $ perf script
      seq 14195 [000] 1927993.748254: probe_libc:malloc: (7f9ff8edd320) bytes=0x22
                  7f9ff8edd320 malloc (/lib/x86_64-linux-gnu/libc-2.22.so)
                  7f9ff8e8eab0 set_binding_values.part.0 (/lib/x86_64-linux-gnu/libc-2.22.so)
                  7f9ff8e8eda1 __bindtextdomain (/lib/x86_64-linux-gnu/libc-2.22.so)
                        401b22 main (/usr/bin/seq)
                  7f9ff8e82610 __libc_start_main (/lib/x86_64-linux-gnu/libc-2.22.so)
                        402799 _start (/usr/bin/seq)
      ...

  We can also use the scripting facilities.  We create a skeleton perl
  script that simply prints out the events

      $ perf script -g perl
      generated Perl script: perf-script.pl

  We can then use this script to see the malloc() calls with a
  backtrace.  Prior to this patch, the backtrace was not available to
  the perl scripts.

      $ perf script -s perf-script.pl
      probe_libc::malloc  0 1927993.748254260  14195 seq   __probe_ip=140325052863264, bytes=34
              [7f9ff8edd320] malloc
              [7f9ff8e8eab0] set_binding_values.part.0
              [7f9ff8e8eda1] __bindtextdomain
              [401b22] main
              [7f9ff8e82610] __libc_start_main
              [402799] _start
      ...

Tested-by: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/87mvphzld0.fsf@secretsauce.net
Signed-off-by: Dima Kogan