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  1. 29 10月, 2014 1 次提交
    • A
      perf tools: Add support for 32-bit compatibility VDSOs · f6832e17
      由 Adrian Hunter 提交于 
      'perf record' post-processes the event stream  to create a list of
build-ids for object files for which sample events have been recorded.
That results in those object files being recorded in the build-id cache.

In the case of VDSO, perf tools reads it from memory and copies it into
a temporary file, which as decribed above, gets added to the build-id
cache.

Then when the perf.data file is processed by other tools, the build-id
of VDSO is listed in the perf.data file and the VDSO can be read from
the build-id cache.  In that case the name of the map, the short name of
the DSO, and the entry in the build-id cache are all "[vdso]".

However, in the 64-bit case, there also can be 32-bit compatibility
VDSOs.

A previous patch added programs "perf-read-vdso32" and "perf
read-vdsox32".

This patch uses those programs to read the correct VDSO for a thread and
create a temporary file just as for the 64-bit VDSO.

The map name and the entry in the build-id cache are still "[vdso]" but
the DSO short name becomes "[vdso32]" and "[vdsox32]" respectively.
Signed-off-by: NAdrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1414061124-26830-16-git-send-email-adrian.hunter@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      f6832e17
  3. 24 7月, 2014 4 次提交
  5. 11 9月, 2012 1 次提交
    • J
      perf tools: Back [vdso] DSO with real data · 7dbf4dcf
      由 Jiri Olsa 提交于 
      Storing data for VDSO shared object, because we need it for the post
unwind processing.

The VDSO shared object is same for all process on a running system, so
it makes no difference when we store it inside the tracer - perf.

When [vdso] map memory is hit, we retrieve [vdso] DSO image and store it
into temporary file.

During the build-id processing phase, the [vdso] DSO image is stored in
build-id db, and build-id reference is made inside perf.data. The
build-id vdso file object is called '[vdso]'. We don't use temporary
file name which gets removed when record is finished.

During report phase the vdso build-id object is treated as any other
build-id DSO object.

Adding following API for vdso object:

  bool is_vdso_map(const char *filename)
    - returns true if the filename matches vdso map name

  struct dso *vdso__dso_findnew(struct list_head *head)
    - find/create proper vdso DSO object

  vdso__exit(void)
    - removes temporary VDSO image if there's any

This change makes backtrace dwarf post unwind possible from [vdso] maps.

Following output is current report of [vdso] sample dwarf backtrace:

  # Overhead  Command      Shared Object                         Symbol
  # ........  .......  .................  .............................
  #
      99.52%       ex  [vdso]             [.] 0x00007fff3ace89af
                   |
                   --- 0x7fff3ace89af

Following output is new report of [vdso] sample dwarf backtrace:

  # Overhead  Command      Shared Object                         Symbol
  # ........  .......  .................  .............................
  #
      99.52%       ex  [vdso]             [.] 0x00000000000009af
                   |
                   --- 0x7fff3ace89af
                       main
                       __libc_start_main
                       _start
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1347295819-23177-5-git-send-email-jolsa@redhat.com
[ committer note: s/ALIGN/PERF_ALIGN/g to cope with the android build changes ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      7dbf4dcf