Re: where is the list of kernel tracepoint defined?

[Shiyao Ma <i at introo dot me>]

My question is about kernel tracepoint.  The second part in your answer applies.


Thanks you guys.

On Tue, Mar 28, 2017 at 11:30 PM, David Smith <dsmith@redhat.com> wrote:
> The answer is it depends on what you mean by "trace points".
>
> If by "trace points" you mean "possible probe locations", then here's
> your answer:
>
> There is no single file in the systemtap source code that lists all
> possible probe locations. You could look through all the tapset
> (*.stp) files for the predefined probe points we provide (but there is
> not guarantee that all those probe points exist in your particular
> kernel). Arkady is correct, that systemtap parses the kernel debuginfo
> to get the 'stap -L' output for kernel functions. The list of all
> possible kernel functions is further constrained by systemtap's
> blacklist.
>
> If by "trace points" you mean "tracepoints" (i.e. predefined kernel
> hooks were probes can be placed), then here's your answer:
>
> There is no single file in the systemtap source code that lists all
> possible kernel tracepoints. Instead, when you run "stap -l
> 'kernel.trace("*")'", systemtap goes and tries to compile the
> tracepoint kernel header files and look for tracepoint definitions in
> them.
>
> Shiyao, perhaps you can clarify a bit what you are really asking.
>
>
> On Tue, Mar 28, 2017 at 4:12 AM, Arkady <arkady.miasnikov@gmail.com> wrote:
>> Hi Shiyao,
>>
>> My understanding is that STAP loads the probe points from the Linux
>> kernel debug information. Probably you can parse the DWARF and find
>> the probe points.
>>
>> Arkady
>>
>> On Tue, Mar 28, 2017 at 11:53 AM, Shiyao Ma <i@introo.me> wrote:
>>> Hi,
>>>
>>>
>>> I'd like to see an index of all kernel trace points.
>>>
>>>
>>> I am aware "stap -L" can do this.  but I am interested if there is
>>> some file in the systemtap source code that lists such trace points?
>>>
>>>
>>> Thanks.
>
>
>
> --
> David Smith
> dsmith@redhat.com
> Red Hat
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