linux-stable.git/tools/perf/util/map.c, branch v4.12.2

perf symbols: Allow user probes on versioned symbols

2017-05-02T21:23:11+00:00

Symbol versioning, as in glibc, results in symbols being defined as:

  @[@]

(Note that "@@" identifies a default symbol, if the symbol name is
repeated.)

perf is currently unable to deal with this, and is unable to create user
probes at such symbols:

  --
  $ nm /lib/powerpc64le-linux-gnu/libpthread.so.0 | grep pthread_create
  0000000000008d30 t __pthread_create_2_1
  0000000000008d30 T pthread_create@@GLIBC_2.17
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  probe-definition(0): pthread_create
  symbol:pthread_create file:(null) line:0 offset:0 return:0 lazy:(null)
  0 arguments
  Open Debuginfo file: /usr/lib/debug/lib/powerpc64le-linux-gnu/libpthread-2.19.so
  Try to find probe point from debuginfo.
  Probe point 'pthread_create' not found.
     Error: Failed to add events. Reason: No such file or directory (Code: -2)
  --

One is not able to specify the fully versioned symbol, either, due to
syntactic conflicts with other uses of "@" by perf:

  --
  $ /usr/bin/sudo perf probe -v -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create@@GLIBC_2.17
  probe-definition(0): pthread_create@@GLIBC_2.17
  Semantic error :SRC@SRC is not allowed.
  0 arguments
     Error: Command Parse Error. Reason: Invalid argument (Code: -22)
  --

This patch ignores versioning for default symbols, thus allowing probes to be
created for these symbols:

  --
  $ /usr/bin/sudo ./perf probe -x /lib/powerpc64le-linux-gnu/libpthread.so.0 pthread_create
  Added new event:
     probe_libpthread:pthread_create (on pthread_create in /lib/powerpc64le-linux-gnu/libpthread-2.19.so)

  You can now use it in all perf tools, such as:

           perf record -e probe_libpthread:pthread_create -aR sleep 1

  $ /usr/bin/sudo ./perf record -e probe_libpthread:pthread_create -aR ./test 2
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.052 MB perf.data (2 samples) ]
  $ /usr/bin/sudo ./perf script
               test  2915 [000] 19124.260729: probe_libpthread:pthread_create: (3fff99248d38)
               test  2916 [000] 19124.260962: probe_libpthread:pthread_create: (3fff99248d38)
  $ /usr/bin/sudo ./perf probe --del=probe_libpthread:pthread_create
  Removed event: probe_libpthread:pthread_create
  --

Committer note:

Change the variable storing the result of strlen() to 'int', to fix the build
on debian:experimental-x-mipsel, fedora:24-x-ARC-uClibc, ubuntu:16.04-x-arm,
etc:

  util/symbol.c: In function 'symbol__match_symbol_name':
  util/symbol.c:422:11: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if (len < versioning - name)
             ^

Signed-off-by: Paul A. Clarke 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Masami Hiramatsu 
Cc: David Ahern 
Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf str{filter,list}: Disentangle headers

2017-04-19T16:01:52+00:00

There are places where we just need a forward declaration, and others
were we need to include strlist.h and/or strfilter.h, reducing the
impact of changes in headers on the build time, do it.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-zab42gbiki88y9k0csorxekb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Move srcline definitions to separate header

2017-04-19T16:01:50+00:00

Out of util.h into a new file, srcline.h

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-ludnlm4djqcdjziekzr4s3u9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Enable sorting by srcline as key

2017-03-27T15:13:28+00:00

Often it is interesting to know how costly a given source line is in
total. Previously, one had to build these sums manually based on all
addresses that pointed to the same source line. This patch introduces
srcline as a sort key, which will do the aggregation for us.

Paired with the recent addition of showing inline frames, this makes
perf report much more useful for many C++ work loads.

The following shows the new feature in action. First, let's show the
status quo output when we sort by address. The result contains many hist
entries that generate the same output:

  ~~~~~~~~~~~~~~~~
  $ perf report --stdio --inline -g address
  # Children      Self  Command       Shared Object        Symbol
  # ........  ........  ............  ...................  .........................................
  #
      99.89%    35.34%  cpp-inlining  cpp-inlining         [.] main
            |
            |--64.55%--main complex:655
            |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
            |          /usr/include/c++/6.3.1/complex:664 (inline)
            |          |
            |          |--60.31%--hypot +20
            |          |          |
            |          |          |--8.52%--__hypot_finite +273
            |          |          |
            |          |          |--7.32%--__hypot_finite +411
...
             --35.34%--_start +4194346
                       __libc_start_main +241
                       |
                       |--6.65%--main random.tcc:3326
                       |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
                       |
                       |--2.70%--main random.tcc:3326
                       |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
                       |
                       |--1.69%--main random.tcc:3326
                       |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
  ...
  ~~~~~~~~~~~~~~~~

With this patch and `-g srcline` we instead get the following output:

  ~~~~~~~~~~~~~~~~
  $ perf report --stdio --inline -g srcline
  # Children      Self  Command       Shared Object        Symbol
  # ........  ........  ............  ...................  .........................................
  #
      99.89%    35.34%  cpp-inlining  cpp-inlining         [.] main
            |
            |--64.55%--main complex:655
            |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
            |          /usr/include/c++/6.3.1/complex:664 (inline)
            |          |
            |          |--64.02%--hypot
            |          |          |
            |          |           --59.81%--__hypot_finite
            |          |
            |           --0.53%--cabs
            |
             --35.34%--_start
                       __libc_start_main
                       |
                       |--12.48%--main random.tcc:3326
                       |          /home/milian/projects/kdab/rnd/hotspot/tests/test-clients/cpp-inlining/main.cpp:39 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1809 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:1818 (inline)
                       |          /usr/include/c++/6.3.1/bits/random.h:185 (inline)
  ...
  ~~~~~~~~~~~~~~~~

Signed-off-by: Milian Wolff 
Cc: Jiri Olsa 
Cc: Yao Jin 
Link: http://lkml.kernel.org/r/20170318214928.9047-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Convert map_groups.refcnt from atomic_t to refcount_t

2017-03-03T22:07:15+00:00

The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: David Windsor 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Kook 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andrew Morton 
Cc: David Windsor 
Cc: Greg Kroah-Hartman 
Cc: Hans Liljestrand 
Cc: Jiri Olsa 
Cc: Kees Kook 
Cc: Mark Rutland 
Cc: Matija Glavinic Pecotic 
Cc: Peter Zijlstra 
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-7-git-send-email-elena.reshetova@intel.com
[ Did the missing conversion of tests/thread-mg-share.c too ]
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Convert map.refcnt from atomic_t to refcount_t

2017-03-03T22:07:15+00:00

The refcount_t type and corresponding API should be used instead of
atomic_t when the variable is used as a reference counter.

This allows to avoid accidental refcounter overflows that might lead to
use-after-free situations.

Signed-off-by: Elena Reshetova 
Signed-off-by: David Windsor 
Signed-off-by: Hans Liljestrand 
Signed-off-by: Kees Kook 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andrew Morton 
Cc: David Windsor 
Cc: Greg Kroah-Hartman 
Cc: Hans Liljestrand 
Cc: Jiri Olsa 
Cc: Kees Kook 
Cc: Mark Rutland 
Cc: Matija Glavinic Pecotic 
Cc: Peter Zijlstra 
Cc: alsa-devel@alsa-project.org
Link: http://lkml.kernel.org/r/1487691303-31858-6-git-send-email-elena.reshetova@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: dso->name is an array, no need to check it against NULL

2017-02-13T20:22:35+00:00

As it will always evaluate to 'true', as reported by clang:

  util/map.c:390:36: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
          if (map && map->dso && (map->dso->name || map->dso->long_name)) {
                                  ~~~~~~~~~~^~~~ ~~
  util/map.c:393:22: error: address of array 'map->dso->name' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion]
                  else if (map->dso->name)
                     ~~  ~~~~~~~~~~^~~~

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: http://lkml.kernel.org/n/tip-x8cu007cly40kfp8xnpi9kya@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf hists browser: Dynamically change verbosity level

2016-10-24T14:07:42+00:00

Here is a small patch which tries to fulfill a point in the perf todo
list:

* Make pressing 'V' multiple times to go on cycling thru various
  verbosity levels in 'perf top', so that info that is present in
  'perf top -v' can be obtained without having to restart the tool
  (acme).

After a small grep in the code, the max verbosity level seems 3; so,
we cycle at 4; I did not dare define a MAX_VERBOSE_LEVEL constant.

Signed-off-by: Alexis Berlemont 
Suggested-and-Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20161012214823.14324-2-alexis.berlemont@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Do hugetlb handling in more systems

2016-09-13T18:26:30+00:00

The csets:

  0ac3348e5024 ("perf tools: Recognize hugetlb mapping as anon mapping")
  d7e404af115b ("perf record: Mark MAP_HUGETLB when synthesizing mmap events")

Added code conditional on MAP_HUGETLB, to make it build in older systems
where that define wasn't available. Now that we grabbed copies of
uapi/linux/mmap.h to have all those definitions in tools/, use it so
that we can support building the tools for older systems (without the
MAP_HUGETLB define in its libc headers) using new kernels that support
such maps.

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Cc: Zefan Li 
Link: http://lkml.kernel.org/n/tip-wv6oqbfkpxbix4umj2kcfmaz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Recognize hugetlb mapping as anon mapping

2016-09-08T15:28:06+00:00

Hugetlbfs mapping should be recognized as anon mapping so user has a
chance to create /tmp/perf-.map file for symbol resolving. This
patch utilizes MAP_HUGETLB to identify hugetlb mapping.

After this patch, if perf is started before a program starts using huge
pages (so perf gets MMAP2 events from kernel), perf is able to recognize
hugetlb mapping as anon mapping.

Signed-off-by: Wang Nan 
Cc: He Kuang 
Cc: Nilay Vaish 
Cc: Zefan Li 
Link: http://lkml.kernel.org/r/1473137909-142064-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Hou Pengyang 
Signed-off-by: Arnaldo Carvalho de Melo