Re: [RFC PATCH perf/core v2 00/16] perf-probe --cache and SDT support

[Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>]

On 2015/07/28 0:16, Arnaldo Carvalho de Melo wrote:
> Em Mon, Jul 27, 2015 at 11:03:20PM +0900, Namhyung Kim escreveu:
>> On Fri, Jul 24, 2015 at 12:52:37PM -0300, Arnaldo Carvalho de Melo wrote:
>>>> If we agreed to extend the event format, I'd like to keep it simple
>>>> and to make it optional to add more info (separated by colon?).
>>>
>>> Reading this again after writing what is below: my suggestion is to use
>>> @, see rationale below.
>>
>> I'm fine with using @.
>  
>>> I would show what desambiguates them in non verbose mode, i.e., the
>>> above would be:
>>>
>>>    $ perf list sdt_foo:bar
>>>
>>>    sdt_foo:bar:dir1/libfoo1.so   [User SDT event]
>>>    sdt_foo:bar:dir2/libfoo1.so   [User SDT event]
>>>    sdt_foo:bar:libfoo2.so        [User SDT event]
>>
>> Then it should use @ here too.
> 
> Right.
>  
> <SNIP>
> 
>>> 	That would be something like this:
> 
>>>     perf record -e sdt_foo:bar@0x1234
> 
>>> 	Because in this case the 'at' meaning of '@' makes sense, i.e.
>>> use the std_foo:bar event at the DSO with a 0x1234 buildid?
>>
>> IMHO @ looks perfect for pathnames but I don't know about build-id as
>> it can be thought as some address.  Anyway I still think @ is a good
>> choice though. ;-)
> 
> Yeah, perhaps we need further clarification? I.e. something like:
> 
> 	sdt_foo:bar:libfoo1.so@buildid(0x1234)
> 
> Or something else, perhaps shorter, that clarifies that it is a buildid?

Hmm, Do we really need such additional buildid? Even though, I think
the build id should have different delimiter, like '%', as below.

sdt_foo:bar@libfoo1.so%buildid


Thank you,

-- 
Masami HIRAMATSU
Linux Technology Research Center, System Productivity Research Dept.
Center for Technology Innovation - Systems Engineering
Hitachi, Ltd., Research & Development Group
E-mail: masami.hiramatsu.pt@hitachi.com