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SubjectRe: [PATCH v3 2/2] Support interactive annotation of code without symbols
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On 2/24/20 7:21 PM, Jiri Olsa wrote:
> On Mon, Feb 24, 2020 at 06:55:12PM +0530, Ravi Bangoria wrote:
>> Hi Jin,
>>
>> On 2/24/20 7:52 AM, 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 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.
>>
>> If I press 'a' on address, it's not annotating. But if I annotate
>> by pressing enter, like you explained, it works. Is it intentional?
>
> I saw that too, but I thought it's unrelated issue,
> because we played with that just recently
>
> if you go through the 'enter' way and back, then the
> next time 'a' works ;-)

Yes.

I liked the series so I was trying out the patches. Just reporting issues I found...

jump/call arrows are also screwed up.. Like jump instruction is showing call arrows.
But these all are minor issues and can be fixed later on. I don't mind ;)

Ravi

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