Re: [PATCH v4 2/2] perf report: Support interactive annotation of code without symbols

Jin, Yao
2020-02-27T00:05:32Z

On 2/26/2020 11:38 PM, Jiri Olsa wrote:
> On Tue, Feb 25, 2020 at 01:14:38PM +0800, Jin Yao wrote:
>> For perf report on stripped binaries it is currently impossible to do
>> annotation. The annotation state is all tied to symbols, but there are
>> either no symbols, or symbols are not covering all the code.
>>
>> We should support the annotation functionality even without symbols.
>>
>> This patch fakes a dummy symbol and the symbol name is the string of
>> address. After that, we just follow current annotation working flow.
>>
>> For example,
>>
>> 1. perf report
>>
>> Overhead Command Shared Object Symbol
>> 20.67% div libc-2.27.so [.] __random_r
>> 17.29% div libc-2.27.so [.] __random
>> 10.59% div div [.] 0x0000000000000628
>> 9.25% div div [.] 0x0000000000000612
>> 6.11% div div [.] 0x0000000000000645
>>
>> 2. Select the line of "10.59% div div [.] 0x0000000000000628" and ENTER.
>>
>> Annotate 0x0000000000000628
>> Zoom into div thread
>> Zoom into div DSO (use the 'k' hotkey to zoom directly into the kernel)
>> Browse map details
>> Run scripts for samples of symbol [0x0000000000000628]
>> Run scripts for all samples
>> Switch to another data file in PWD
>> Exit
>>
>> 3. Select the "Annotate 0x0000000000000628" and ENTER.
>>
>> Percent│
>> │
>> │
>> │ Disassembly of section .text:
>> │
>> │ 0000000000000628 <.text+0x68>:
>> │ divsd %xmm4,%xmm0
>> │ divsd %xmm3,%xmm1
>> │ movsd (%rsp),%xmm2
>> │ addsd %xmm1,%xmm0
>> │ addsd %xmm2,%xmm0
>> │ movsd %xmm0,(%rsp)
>>
>> Now we can see the dump of object starting from 0x628.
>>
>> We can also press hotkey 'a' on address in report view.
>> For branch mode, we only support the annotation for
>> "branch to" address.
>>
>> v4:
>> ---
>> 1. Support the hotkey 'a'. When we press 'a' on address,
>> now it supports the annotation.
>
> please move this to separate patch, AFAICS it's separate change
> and was broken before your change
>
> thanks,
> jirka
>

OK, I will move it to a separate patch.

Thanks
Jin Yao