Re: how to get a kernel callgraph starting from a syscall

[Francis Moreau <francis.moro@gmail.com>]

On Thu, Apr 21, 2011 at 5:23 PM, David Ahern <dsahern@gmail.com> wrote:
>
>
> On 04/21/11 01:46, Francis Moreau wrote:
>> Hello,
>>
>> Sorry if the question is dumb but I'm a bit lost about this.
>>
>> I know that ftrace exists but I think that perf can do this too: I
>> have a userspace application which is calling a libc C function (read)
>> which ends up doing a sys_read.
>>
>> For the sys_read, I'd like to see what's happening in the kernel by
>> displaying the call graph.
>>
>> Can perf do that ?
>
> Have you tried 'perf record -g'?
>

Well, I don't see how it can be done with perf record -g.

Let's say I'm interested to see the path taken in the kernel when a
process is calling sys_sleep:

  $ perf record -g sleep 1

Then I can use:

  $ perf report -g

But I don't see what I am asking for.

What am I missing ?

Thanks
-- 
Francis