Wei Li e6786f8686 perf annotate: Fix getting source line failure
[ Upstream commit 11db1ad451 ]

The output of "perf annotate -l --stdio xxx" changed since commit 425859ff0d
("perf annotate: No need to calculate notes->start twice") removed notes->start
assignment in symbol__calc_lines(). It will get failed in
find_address_in_section() from symbol__tty_annotate() subroutine as the
a2l->addr is wrong. So the annotate summary doesn't report the line number of
source code correctly.

Before fix:

  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ cat common_while_1.c
  void hotspot_1(void)
  {
	volatile int i;

	for (i = 0; i < 0x10000000; i++);
	for (i = 0; i < 0x10000000; i++);
	for (i = 0; i < 0x10000000; i++);
  }

  int main(void)
  {
	hotspot_1();

	return 0;
  }
  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ gcc common_while_1.c -g -o common_while_1

  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ sudo ./perf record ./common_while_1
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.488 MB perf.data (12498 samples) ]
  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ sudo ./perf annotate -l -s hotspot_1 --stdio

  Sorted summary for file /home/liwei/main_code/hulk_work/hulk/tools/perf/common_while_1
  ----------------------------------------------

   19.30 common_while_1[32]
   19.03 common_while_1[4e]
   19.01 common_while_1[16]
    5.04 common_while_1[13]
    4.99 common_while_1[4b]
    4.78 common_while_1[2c]
    4.77 common_while_1[10]
    4.66 common_while_1[2f]
    4.59 common_while_1[51]
    4.59 common_while_1[35]
    4.52 common_while_1[19]
    4.20 common_while_1[56]
    0.51 common_while_1[48]
   Percent |      Source code & Disassembly of common_while_1 for cycles:ppp (12480 samples, percent: local period)
  -----------------------------------------------------------------------------------------------------------------
         :
         :
         :
         :         Disassembly of section .text:
         :
         :         00000000000005fa <hotspot_1>:
         :         hotspot_1():
         :         void hotspot_1(void)
         :         {
    0.00 :   5fa:   push   %rbp
    0.00 :   5fb:   mov    %rsp,%rbp
         :                 volatile int i;
         :
         :                 for (i = 0; i < 0x10000000; i++);
    0.00 :   5fe:   movl   $0x0,-0x4(%rbp)
    0.00 :   605:   jmp    610 <hotspot_1+0x16>
    0.00 :   607:   mov    -0x4(%rbp),%eax
   common_while_1[10]    4.77 :   60a:   add    $0x1,%eax
   common_while_1[13]    5.04 :   60d:   mov    %eax,-0x4(%rbp)
   common_while_1[16]   19.01 :   610:   mov    -0x4(%rbp),%eax
   common_while_1[19]    4.52 :   613:   cmp    $0xfffffff,%eax
      0.00 :   618:   jle    607 <hotspot_1+0xd>
           :                 for (i = 0; i < 0x10000000; i++);
  ...

After fix:

  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ sudo ./perf record ./common_while_1
  [ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 0.488 MB perf.data (12500 samples) ]
  liwei@euler:~/main_code/hulk_work/hulk/tools/perf$ sudo ./perf annotate -l -s hotspot_1 --stdio

  Sorted summary for file /home/liwei/main_code/hulk_work/hulk/tools/perf/common_while_1
  ----------------------------------------------

   33.34 common_while_1.c:5
   33.34 common_while_1.c:6
   33.32 common_while_1.c:7
   Percent |      Source code & Disassembly of common_while_1 for cycles:ppp (12482 samples, percent: local period)
  -----------------------------------------------------------------------------------------------------------------
         :
         :
         :
         :         Disassembly of section .text:
         :
         :         00000000000005fa <hotspot_1>:
         :         hotspot_1():
         :         void hotspot_1(void)
         :         {
    0.00 :   5fa:   push   %rbp
    0.00 :   5fb:   mov    %rsp,%rbp
         :                 volatile int i;
         :
         :                 for (i = 0; i < 0x10000000; i++);
    0.00 :   5fe:   movl   $0x0,-0x4(%rbp)
    0.00 :   605:   jmp    610 <hotspot_1+0x16>
    0.00 :   607:   mov    -0x4(%rbp),%eax
   common_while_1.c:5    4.70 :   60a:   add    $0x1,%eax
    4.89 :   60d:   mov    %eax,-0x4(%rbp)
   common_while_1.c:5   19.03 :   610:   mov    -0x4(%rbp),%eax
   common_while_1.c:5    4.72 :   613:   cmp    $0xfffffff,%eax
    0.00 :   618:   jle    607 <hotspot_1+0xd>
         :                 for (i = 0; i < 0x10000000; i++);
    0.00 :   61a:   movl   $0x0,-0x4(%rbp)
    0.00 :   621:   jmp    62c <hotspot_1+0x32>
    0.00 :   623:   mov    -0x4(%rbp),%eax
   common_while_1.c:6    4.54 :   626:   add    $0x1,%eax
    4.73 :   629:   mov    %eax,-0x4(%rbp)
   common_while_1.c:6   19.54 :   62c:   mov    -0x4(%rbp),%eax
   common_while_1.c:6    4.54 :   62f:   cmp    $0xfffffff,%eax
  ...

Signed-off-by: Wei Li <liwei391@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 425859ff0d ("perf annotate: No need to calculate notes->start twice")
Link: http://lkml.kernel.org/r/20190221095716.39529-1-liwei391@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-05 22:33:03 +02:00
2019-04-05 22:32:59 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%