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  1. 24 5月, 2017 7 次提交
    • N
      perf tools: Put caller above callee in --children mode · 7111ffff
      由 Namhyung Kim 提交于 
      The __hpp__sort_acc() sorts entries using callchain depth in order to
put callers above in children mode.  But it assumed the callchain order
was callee-first.  Now default (for children) is caller-first so the
order of entries is reverted.

For example, consider following case:

  $ perf report --no-children
  ..l
  # Overhead  Command  Shared Object        Symbol
  # ........  .......  ...................  ..........................
  #
      99.44%  a.out    a.out                [.] main
              |
              ---main
                 __libc_start_main
                 _start

Then children mode should show 'start' above '__libc_start_main' since
it's the caller (parent) of the __libc_start_main.  But it's reversed:

  # Children      Self  Command  Shared Object    Symbol
  # ........  ........  .......  ...............  .....................
  #
      99.61%     0.00%  a.out    libc-2.25.so     [.] __libc_start_main
      99.61%     0.00%  a.out    a.out            [.] _start
      99.54%    99.44%  a.out    a.out            [.] main

This patch fixes it.

  # Children      Self  Command  Shared Object    Symbol
  # ........  ........  .......  ...............  .....................
  #
      99.61%     0.00%  a.out    a.out            [.] _start
      99.61%     0.00%  a.out    libc-2.25.so     [.] __libc_start_main
      99.54%    99.44%  a.out    a.out            [.] main
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-8-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7111ffff
    • M
      perf report: Do not drop last inlined frame · 4d53b9d5
      由 Milian Wolff 提交于 
      The very last inlined frame, i.e. the one furthest away from the
non-inlined frame, was silently dropped. This is apparent when
comparing the output of `perf script` and `addr2line`:

~~~~~~
  $ perf script --inline
  ...
  a.out 26722 80836.309329:      72425 cycles:
                     21561 __hypot_finite (/usr/lib/libm-2.25.so)
                      ace3 hypot (/usr/lib/libm-2.25.so)
                       a4a main (a.out)
                           std::abs<double>
                           std::_Norm_helper<true>::_S_do_it<double>
                           std::norm<double>
                           main
                     20510 __libc_start_main (/usr/lib/libc-2.25.so)
                       bd9 _start (a.out)

  $ addr2line -a -f -i -e /tmp/a.out a4a | c++filt
  0x0000000000000a4a
  std::__complex_abs(doublecomplex )
  /usr/include/c++/6.3.1/complex:589
  double std::abs<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:597
  double std::_Norm_helper<true>::_S_do_it<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:654
  double std::norm<double>(std::complex<double> const&)
  /usr/include/c++/6.3.1/complex:664
  main
  /tmp/inlining.cpp:14
~~~~~

Note how `std::__complex_abs` is missing from the `perf script`
output. This is similarly showing up in `perf report`. The patch
here fixes this issue, and the output becomes:

~~~~~
  a.out 26722 80836.309329:      72425 cycles:
                     21561 __hypot_finite (/usr/lib/libm-2.25.so)
                      ace3 hypot (/usr/lib/libm-2.25.so)
                       a4a main (a.out)
                           std::__complex_abs
                           std::abs<double>
                           std::_Norm_helper<true>::_S_do_it<double>
                           std::norm<double>
                           main
                     20510 __libc_start_main (/usr/lib/libc-2.25.so)
                       bd9 _start (a.out)
~~~~~
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-7-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      4d53b9d5
    • M
      perf report: Always honor callchain order for inlined nodes · 28071f51
      由 Milian Wolff 提交于 
      So far, the inlined nodes where only reversed when we built perf
against libbfd. If that was not available, the addr2line fallback
code path was missing the inline_list__reverse call.

Now we always add the nodes in the correct order within
inline_list__append. This removes the need to reverse the list
and also ensures that all callers construct the list in the right
order.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-6-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      28071f51
    • N
      perf script: Add --inline option for debugging · 325fbff5
      由 Namhyung Kim 提交于 
      The --inline option is to show inlined functions in callchains.

For example:

  $ perf script
  a.out  5644 11611.467597:     309961 cycles:u:
                     790 main (/home/namhyung/tmp/perf/a.out)
                   20511 __libc_start_main (/usr/lib/libc-2.25.so)
                     8ba _start (/home/namhyung/tmp/perf/a.out)
  ...

  $ perf script --inline
  a.out  5644 11611.467597:     309961 cycles:u:
                     790 main (/home/namhyung/tmp/perf/a.out)
                         std::__detail::_Adaptor<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul>, double>::operator()
                         std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >
                         std::uniform_real_distribution<double>::operator()<std::linear_congruential_engine<unsigned long, 16807ul, 0ul, 2147483647ul> >
                         main
                   20511 __libc_start_main (/usr/lib/libc-2.25.so)
                     8ba _start (/home/namhyung/tmp/perf/a.out)
  ...
Reviewed-and-tested-by: NMilian Wolff <milian.wolff@kdab.com>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-5-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      325fbff5
    • M
      perf report: Fix off-by-one for non-activation frames · 1982ad48
      由 Milian Wolff 提交于 
      As the documentation for dwfl_frame_pc says, frames that
are no activation frames need to have their program counter
decremented by one to properly find the function of the caller.

This fixes many cases where perf report currently attributes
the cost to the next line. I.e. I have code like this:

~~~~~~~~~~~~~~~
  #include <thread>
  #include <chrono>

  using namespace std;

  int main()
  {
    this_thread::sleep_for(chrono::milliseconds(1000));
    this_thread::sleep_for(chrono::milliseconds(100));
    this_thread::sleep_for(chrono::milliseconds(10));

    return 0;
  }
~~~~~~~~~~~~~~~

Now compile and record it:

~~~~~~~~~~~~~~~
  g++ -std=c++11 -g -O2 test.cpp
  echo 1 | sudo tee /proc/sys/kernel/sched_schedstats
  perf record \
    --event sched:sched_stat_sleep \
    --event sched:sched_process_exit \
    --event sched:sched_switch --call-graph=dwarf \
    --output perf.data.raw \
    ./a.out
  echo 0 | sudo tee /proc/sys/kernel/sched_schedstats
  perf inject --sched-stat --input perf.data.raw --output perf.data
~~~~~~~~~~~~~~~

Before this patch, the report clearly shows the off-by-one issue.
Most notably, the last sleep invocation is incorrectly attributed
to the "return 0;" line:

~~~~~~~~~~~~~~~
  Overhead  Source:Line
  ........  ...........

   100.00%  core.c:0
            |
            ---__schedule core.c:0
               schedule
               do_nanosleep hrtimer.c:0
               hrtimer_nanosleep
               sys_nanosleep
               entry_SYSCALL_64_fastpath .tmp_entry_64.o:0
               __nanosleep_nocancel .:0
               std::this_thread::sleep_for<long, std::ratio<1l, 1000l> > thread:323
               |
               |--90.08%--main test.cpp:9
               |          __libc_start_main
               |          _start
               |
               |--9.01%--main test.cpp:10
               |          __libc_start_main
               |          _start
               |
                --0.91%--main test.cpp:13
                          __libc_start_main
                          _start
~~~~~~~~~~~~~~~

With this patch here applied, the issue is fixed. The report becomes
much more usable:

~~~~~~~~~~~~~~~
  Overhead  Source:Line
  ........  ...........

   100.00%  core.c:0
            |
            ---__schedule core.c:0
               schedule
               do_nanosleep hrtimer.c:0
               hrtimer_nanosleep
               sys_nanosleep
               entry_SYSCALL_64_fastpath .tmp_entry_64.o:0
               __nanosleep_nocancel .:0
               std::this_thread::sleep_for<long, std::ratio<1l, 1000l> > thread:323
               |
               |--90.08%--main test.cpp:8
               |          __libc_start_main
               |          _start
               |
               |--9.01%--main test.cpp:9
               |          __libc_start_main
               |          _start
               |
                --0.91%--main test.cpp:10
                          __libc_start_main
                          _start
~~~~~~~~~~~~~~~

Similarly it works for signal frames:

~~~~~~~~~~~~~~~
  __noinline void bar(void)
  {
    volatile long cnt = 0;

    for (cnt = 0; cnt < 100000000; cnt++);
  }

  __noinline void foo(void)
  {
    bar();
  }

  void sig_handler(int sig)
  {
    foo();
  }

  int main(void)
  {
    signal(SIGUSR1, sig_handler);
    raise(SIGUSR1);

    foo();
    return 0;
  }
~~~~~~~~~~~~~~~~

Before, the report wrongly points to `signal.c:29` after raise():

~~~~~~~~~~~~~~~~
  $ perf report --stdio --no-children -g srcline -s srcline
  ...
   100.00%  signal.c:11
            |
            ---bar signal.c:11
               |
               |--50.49%--main signal.c:29
               |          __libc_start_main
               |          _start
               |
                --49.51%--0x33a8f
                          raise .:0
                          main signal.c:29
                          __libc_start_main
                          _start
~~~~~~~~~~~~~~~~

With this patch in, the issue is fixed and we instead get:

~~~~~~~~~~~~~~~~
   100.00%  signal   signal            [.] bar
            |
            ---bar signal.c:11
               |
               |--50.49%--main signal.c:29
               |          __libc_start_main
               |          _start
               |
                --49.51%--0x33a8f
                          raise .:0
                          main signal.c:27
                          __libc_start_main
                          _start
~~~~~~~~~~~~~~~~

Note how this patch fixes this issue for both unwinding methods, i.e.
both dwfl and libunwind. The former case is straight-forward thanks
to dwfl_frame_pc(). For libunwind, we replace the functionality via
unw_is_signal_frame() for any but the very first frame.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-4-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1982ad48
    • M
      perf report: Fix memory leak in addr2line when called by addr2inlines · b21cc978
      由 Milian Wolff 提交于 
      When a filename was found in addr2line it was duplicated via strdup()
but never freed. Now we pass NULL and handle this gracefully in
addr2line.

Detected by Valgrind:

  ==16331== 1,680 bytes in 21 blocks are definitely lost in loss record 148 of 220
  ==16331==    at 0x4C2AF1F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
  ==16331==    by 0x672FA69: strdup (in /usr/lib/libc-2.25.so)
  ==16331==    by 0x52769F: addr2line (srcline.c:256)
  ==16331==    by 0x52769F: addr2inlines (srcline.c:294)
  ==16331==    by 0x52769F: dso__parse_addr_inlines (srcline.c:502)
  ==16331==    by 0x574D7A: inline__fprintf (hist.c:41)
  ==16331==    by 0x574D7A: ipchain__fprintf_graph (hist.c:147)
  ==16331==    by 0x57518A: __callchain__fprintf_graph (hist.c:212)
  ==16331==    by 0x5753CF: callchain__fprintf_graph.constprop.6 (hist.c:337)
  ==16331==    by 0x57738E: hist_entry__fprintf (hist.c:628)
  ==16331==    by 0x57738E: hists__fprintf (hist.c:882)
  ==16331==    by 0x44A20F: perf_evlist__tty_browse_hists (builtin-report.c:399)
  ==16331==    by 0x44A20F: report__browse_hists (builtin-report.c:491)
  ==16331==    by 0x44A20F: __cmd_report (builtin-report.c:624)
  ==16331==    by 0x44A20F: cmd_report (builtin-report.c:1054)
  ==16331==    by 0x4A49CE: run_builtin (perf.c:296)
  ==16331==    by 0x4A4CC0: handle_internal_command (perf.c:348)
  ==16331==    by 0x434371: run_argv (perf.c:392)
  ==16331==    by 0x434371: main (perf.c:530)
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-3-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      b21cc978
    • M
      perf report: Don't crash on invalid maps in `-g srcline` mode · 7d4df089
      由 Milian Wolff 提交于 
      I just hit a segfault when doing `perf report -g srcline`.
Valgrind pointed me at this code as the culprit:

  ==8359== Invalid read of size 8
  ==8359==    at 0x3096D9: map__rip_2objdump (map.c:430)
  ==8359==    by 0x2FC1A3: match_chain_srcline (callchain.c:645)
  ==8359==    by 0x2FC1A3: match_chain (callchain.c:700)
  ==8359==    by 0x2FC1A3: append_chain (callchain.c:895)
  ==8359==    by 0x2FC1A3: append_chain_children (callchain.c:846)
  ==8359==    by 0x2FF719: callchain_append (callchain.c:944)
  ==8359==    by 0x2FF719: hist_entry__append_callchain (callchain.c:1058)
  ==8359==    by 0x32FA06: iter_add_single_cumulative_entry (hist.c:908)
  ==8359==    by 0x33195C: hist_entry_iter__add (hist.c:1050)
  ==8359==    by 0x258F65: process_sample_event (builtin-report.c:204)
  ==8359==    by 0x30D60C: perf_session__deliver_event (session.c:1310)
  ==8359==    by 0x30D60C: ordered_events__deliver_event (session.c:119)
  ==8359==    by 0x310D12: __ordered_events__flush (ordered-events.c:210)
  ==8359==    by 0x310D12: ordered_events__flush.part.3 (ordered-events.c:277)
  ==8359==    by 0x30DD3C: perf_session__process_user_event (session.c:1349)
  ==8359==    by 0x30DD3C: perf_session__process_event (session.c:1475)
  ==8359==    by 0x30FC3C: __perf_session__process_events (session.c:1867)
  ==8359==    by 0x30FC3C: perf_session__process_events (session.c:1921)
  ==8359==    by 0x25A985: __cmd_report (builtin-report.c:575)
  ==8359==    by 0x25A985: cmd_report (builtin-report.c:1054)
  ==8359==    by 0x2B9A80: run_builtin (perf.c:296)
  ==8359==  Address 0x70 is not stack'd, malloc'd or (recently) free'd

This patch fixes the issue.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
[ Remove dependency from another change ]
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yao Jin <yao.jin@linux.intel.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170524062129.32529-2-namhyung@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7d4df089
  3. 04 5月, 2017 3 次提交
  5. 03 5月, 2017 3 次提交
    • T
      perf config: Refactor a duplicated code for obtaining config file name · 4341ec6b
      由 Taeung Song 提交于 
      We were doing the same sequence to figure out what is the config
pathname to use, fix it by doing it before those two uses.
Signed-off-by: NTaeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1493209268-5543-2-git-send-email-treeze.taeung@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4341ec6b
    • P
      perf symbols: Allow user probes on versioned symbols · d8040645
      由 Paul Clarke 提交于 
      Symbol versioning, as in glibc, results in symbols being defined as:

  <real symbol>@[@]<version>

(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: NPaul A. Clarke <pc@us.ibm.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/c2b18d9c-17f8-9285-4868-f58b6359ccac@us.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      d8040645
    • A
      perf symbols: Accept symbols starting at address 0 · b843f62a
      由 Arnaldo Carvalho de Melo 提交于 
      That is the case of _text on s390, and we have some functions that return an
address, using address zero to report problems, oops.

This would lead the symbol loading routines to not use "_text" as the reference
relocation symbol, or the first symbol for the kernel, but use instead
"_stext", that is at the same address on x86_64 and others, but not on s390:

  [acme@localhost perf-4.11.0-rc6]$ head -15 /proc/kallsyms
  0000000000000000 T _text
  0000000000000418 t iplstart
  0000000000000800 T start
  000000000000080a t .base
  000000000000082e t .sk8x8
  0000000000000834 t .gotr
  0000000000000842 t .cmd
  0000000000000846 t .parm
  000000000000084a t .lowcase
  0000000000010000 T startup
  0000000000010010 T startup_kdump
  0000000000010214 t startup_kdump_relocated
  0000000000011000 T startup_continue
  00000000000112a0 T _ehead
  0000000000100000 T _stext
  [acme@localhost perf-4.11.0-rc6]$

Which in turn would make 'perf test vmlinux' to fail because it wouldn't find
the symbols before "_stext" in kallsyms.

Fix it by using the return value only for errors and storing the
address, when the symbol is successfully found, in a provided pointer
arg.

Before this patch:

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 40693
  Looking at the vmlinux_path (8 entries long)
  Using /usr/lib/debug/lib/modules/3.10.0-654.el7.s390x/vmlinux for symbols
  ERR : 0: _text not on kallsyms
  ERR : 0x418: iplstart not on kallsyms
  ERR : 0x800: start not on kallsyms
  ERR : 0x80a: .base not on kallsyms
  ERR : 0x82e: .sk8x8 not on kallsyms
  ERR : 0x834: .gotr not on kallsyms
  ERR : 0x842: .cmd not on kallsyms
  ERR : 0x846: .parm not on kallsyms
  ERR : 0x84a: .lowcase not on kallsyms
  ERR : 0x10000: startup not on kallsyms
  ERR : 0x10010: startup_kdump not on kallsyms
  ERR : 0x10214: startup_kdump_relocated not on kallsyms
  ERR : 0x11000: startup_continue not on kallsyms
  ERR : 0x112a0: _ehead not on kallsyms
  <SNIP warnings>
  test child finished with -1
  ---- end ----
  vmlinux symtab matches kallsyms: FAILED!
  [acme@localhost perf-4.11.0-rc6]$

After:

  [acme@localhost perf-4.11.0-rc6]$ tools/perf/perf test -v 1
   1: vmlinux symtab matches kallsyms            :
  --- start ---
  test child forked, pid 47160
  <SNIP warnings>
  test child finished with 0
  ---- end ----
  vmlinux symtab matches kallsyms: Ok
  [acme@localhost perf-4.11.0-rc6]$
Reported-by: NMichael Petlan <mpetlan@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-9x9bwgd3btwdk1u51xie93fz@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b843f62a
  7. 27 4月, 2017 4 次提交
  9. 26 4月, 2017 2 次提交
  11. 25 4月, 2017 12 次提交
  13. 24 4月, 2017 4 次提交
  15. 21 4月, 2017 4 次提交
  17. 20 4月, 2017 1 次提交