Re: [PATCH -tip 6/7] perf bts trace: print function+offset

Peter Zijlstra
2010-12-03T13:00:45Z

On Fri, 2010-12-03 at 13:00 +0900, Akihiro Nagai wrote:
> Provide the function to print function+offset.
> And, set it as the default behavior of 'perf bts trace'.
> To use this function, users can also specify the option '-s' or '--symbol'.
>
> Example: 'perf bts -as trace'
> This command prints address and function+offset.
>
> Output sample:
> address function+offset
> 0xffffffff8146fe0e irq_return+0x0 => 0x00007fd4038e3b20 _start+0x0
> ...
> 0x000000380661ee79 __libc_start_main+0xf9 => 0x00000000004035c3 main+0x0
> 0xffffffff8146ef4e irq_return+0x0 => 0x00000000004035c3 main+0x0
> 0x00000000004035e8 main+0x25 => 0x000000000040bca0 set_program_name+0x0
> 0xffffffff8146ef4e irq_return+0x0 => 0x000000000040bca0 set_program_name+0x0
> 0x000000000040bcae set_program_name+0xe => 0x00000000004023d0 strrchr@plt+0x0
> 0x00000000004023d0 strrchr@plt+0x0 => 0x00000000004023d6 strrchr@plt+0x6
> ...
> 0x0000000000403e0c main+0x849 => 0x00000000004021f0 exit@plt+0x0
> 0x00000000004021f0 exit@plt+0x0 => 0x00000000004021f6 exit@plt+0x6
> 0x00000000004021fb exit@plt+0xb => 0x00000000004020d0 _init+0x18
> 0x00000000004020d6 _init+0x1e => 0x00000038062149d0 _dl_runtime_resolve+0x0

What would be very nice output is something like a source-code browser
(tig might have something worth borrowing) and annotating the output
using the bts output.

You could for example darken the code that didn't get any coverage, and
print a percentage for each conditional statement.

That way you can easily see how your code is traversed.