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

Jiri Olsa
2020-02-26T15:38:27Z

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