Re: [PATCH] stm class: Document the stm_ftrace

From: Alexander Shishkin
Date: Mon Mar 20 2017 - 07:13:52 EST


Chunyan Zhang <zhang.lyra@xxxxxxxxx> writes:

> Hi Alex,
>
> On 20 March 2017 at 16:49, Alexander Shishkin
> <alexander.shishkin@xxxxxxxxxxxxxxx> wrote:
>> Hi Chunyan,
>>
>> A couple of clarifications: iirc this applies to the function tracer
>> of ftrace, right? Does it make sense to mention that? Also, are you
>
> Right, only applies to the function tracer currently (actually only
> function address and parent function address of Function tracer is
> recorded into STM, I mean it doesn't include like "pid" "task name"
> "cpu-id" these information right now). It makes sense to mention
> function tracer, I will address that.

Thanks!

>> planning to support other ftrace payloads like trace_printk()s?
>
> No plan so far, but I think I can consider to do that, it depends on
> how many people think that are helpful.
> What do you think?

Well, I myself almost never use function tracer, but I do use
tracepoints/trace_printk()s. I'm *guessing* that everybody who's
subsystem implement tracepoints will be interested in those.

I confess that I haven't yet looked at the code properly, so I'm a don't
have a picture of what it will take to implement these.

Regards,
--
Alex