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  1. 19 Nov, 2014 16 commits
  3. 16 Nov, 2014 14 commits
  5. 12 Nov, 2014 1 commit
  7. 07 Nov, 2014 1 commit
  9. 06 Nov, 2014 4 commits
  11. 05 Nov, 2014 4 commits
    • Namhyung Kim's avatar
      perf tools: Make vmlinux short name more like kallsyms short name · 96d78059
      Namhyung Kim authored 
      The previous patch changed kernel dso name from '[kernel.kallsyms]' to
vmlinux.  However it might add confusion to old users accustomed to the
old name.  So change the short name to '[kernel.vmlinux]' to reduce such
confusion.

Before:
  # Overhead  Command         Shared Object            Symbol
  # ........  ..............  .......................  ...............................
  #
       9.83%  swapper         vmlinux                  [k] intel_idle
       4.10%  awk             libc-2.20.so             [.] __strcmp_sse2
       1.86%  sed             libc-2.20.so             [.] __strcmp_sse2
       1.78%  netctl-auto     libc-2.20.so             [.] __strcmp_sse2
       1.23%  netctl-auto     libc-2.20.so             [.] __mbrtowc
       1.21%  firefox         libxul.so                [.] 0x00000000024b62bd
       1.20%  swapper         vmlinux                  [k] cpuidle_enter_state
       1.03%  sleep           vmlinux                  [k] copy_user_generic_unrolled

After:
  # Overhead  Command         Shared Object            Symbol
  # ........  ..............  .......................  ...............................
  #
       9.83%  swapper         [kernel.vmlinux]         [k] intel_idle
       4.10%  awk             libc-2.20.so             [.] __strcmp_sse2
       1.86%  sed             libc-2.20.so             [.] __strcmp_sse2
       1.78%  netctl-auto     libc-2.20.so             [.] __strcmp_sse2
       1.23%  netctl-auto     libc-2.20.so             [.] __mbrtowc
       1.21%  firefox         libxul.so                [.] 0x00000000024b62bd
       1.20%  swapper         [kernel.vmlinux]         [k] cpuidle_enter_state
       1.03%  sleep           [kernel.vmlinux]         [k] copy_user_generic_unrolled
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1415063674-17206-9-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      96d78059
    • Namhyung Kim's avatar
      perf tools: Fix build-id matching on vmlinux · b837a8bd
      Namhyung Kim authored 
      There's a problem on finding correct kernel symbols when perf report
runs on a different kernel.  Although a part of the problem was solved
by the prior commit 0a7e6d1b ("perf tools: Check recorded kernel
version when finding vmlinux"), there's a remaining problem still.

When perf records samples, it synthesizes the kernel map using
machine__mmap_name() and ref_reloc_sym like "[kernel.kallsyms]_text".
You can easily see it using 'perf report -D' command.

After finishing record, it goes through the recorded events to find
maps/dsos actually used.  And then record build-id info of them.

During this process, it needs to load symbols in a dso and it'd call
dso__load_vmlinux_path() since the default value of the symbol_conf.
try_vmlinux_path is true.  However it changes dso->long_name to a real
path of the vmlinux file (e.g. /lib/modules/3.16.4/build/vmlinux) if one
is running on a custom kernel.

It resulted in that perf report reads the build-id of the vmlinux, but
cannot use it since it only knows about the [kernel.kallsyms] map.  It
then falls back to possible vmlinux paths by using the recorded kernel
version (in case of a recent version) or a running kernel silently.

Even with the recent tools, this still has a possibility of breaking
the result.  As the build directory is a symbolic link, if one built a
new kernel in the same directory with different source/config, the old
link to vmlinux will point the new file.  So it's absolutely needed to
use build-id when finding a kernel image.

In this patch, it's now changed to try to search a kernel dso in the
existing dso list which was constructed during build-id table parsing
so it'll always have a build-id.  If not found, search "[kernel.kallsyms]".

Before:

  $ perf report
  # Children      Self  Command  Shared Object      Symbol
  # ........  ........  .......  .................  ...............................
  #
      72.15%     0.00%  swapper  [kernel.kallsyms]  [k] set_curr_task_rt
      72.15%     0.00%  swapper  [kernel.kallsyms]  [k] native_calibrate_tsc
      72.15%     0.00%  swapper  [kernel.kallsyms]  [k] tsc_refine_calibration_work
      71.87%    71.87%  swapper  [kernel.kallsyms]  [k] module_finalize
   ...

After (for the same perf.data):

      72.15%     0.00%  swapper  vmlinux  [k] cpu_startup_entry
      72.15%     0.00%  swapper  vmlinux  [k] arch_cpu_idle
      72.15%     0.00%  swapper  vmlinux  [k] default_idle
      71.87%    71.87%  swapper  vmlinux  [k] native_safe_halt
   ...
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/20140924073356.GB1962@gmail.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1415063674-17206-8-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b837a8bd
    • Namhyung Kim's avatar
      perf record: Do not save pathname in ./debug/.build-id directory for vmlinux · 00dc8657
      Namhyung Kim authored 
      When perf record finishes a session, it pre-processes samples in order
to write build-id info from DSOs that had samples.

During this process it'll call map__load() for the kernel map, and it
ends up calling dso__load_vmlinux_path() which replaces dso->long_name.

But this function checks kernel's build-id before searching vmlinux path
so it'll end up with a cryptic name, the pathname for the entry in the
~/.debug cache, which can be confusing to users.

This patch adds a flag to skip the build-id check during record, so
that it'll have the original vmlinux path for the kernel dso->long_name,
not the entry in the ~/.debug cache.

Before:
  # perf record -va sleep 3
  mmap size 528384B
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.196 MB perf.data (~8545 samples) ]
  Looking at the vmlinux_path (7 entries long)
  Using /home/namhyung/.debug/.build-id/f0/6e17aa50adf4d00b88925e03775de107611551 for symbols

After:
  # perf record -va sleep 3
  mmap size 528384B
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.193 MB perf.data (~8432 samples) ]
  Looking at the vmlinux_path (7 entries long)
  Using /lib/modules/3.16.4-1-ARCH/build/vmlinux for symbols
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1415063674-17206-7-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      00dc8657
    • Namhyung Kim's avatar
      perf build-id: Move build-id related functions to util/build-id.c · e195fac8
      Namhyung Kim authored 
      It'd be better managing those functions in a separate place as
util/header.c file is already big.

It now exports following 3 functions to others:

  bool perf_session__read_build_ids(struct perf_session *session, bool with_hits);
  int perf_session__write_buildid_table(struct perf_session *session, int fd);
  int perf_session__cache_build_ids(struct perf_session *session);
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Link: http://lkml.kernel.org/r/545733E7.6010105@intel.com
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1415063674-17206-5-git-send-email-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e195fac8
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