Re: [PATCH 4/9] perf session: Create kernel maps in the constructor

From: Masami Hiramatsu
Date: Thu Jan 28 2010 - 11:29:18 EST


Arnaldo Carvalho de Melo wrote:
> Em Wed, Jan 27, 2010 at 06:17:58PM -0500, Masami Hiramatsu escreveu:
>> Arnaldo Carvalho de Melo wrote:
>>> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
>>>
>>> Removing one extra step needed in the tools that need this, fixing a bug
>>> in 'perf probe' where this was not being done.
>>
>> Thanks,
>> BTW, when O_WRONLY should be used? I guess I might misunderstand something
>> in builtin-probe.c, and it should use O_RDONLY ...
>
> O_RDONLY only when you have a perf.data file, O_WRONLY was thought for
> 'perf record', then for tools that want only to do symbol lookup it was
> reused...

Ah, so that is the mode for perf.data.

> I think we should have a proper enum and more clearly specify these
> semantics, as well as adding a MMAP mode so that we can lift the code
> now in perf top somehow.

Yeah, and if you can separate an interface only for handling symbols
from debug/elf binaries, it will be helpful for me too.

> But for now using O_WRONLY provides what 'perf probe' needs, I guess :-)

I think so ;-)

Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Thank you,

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division

e-mail: mhiramat@xxxxxxxxxx

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