Re: [PATCH 1/2] tracing: Add a trace for task_exit

From: Mathieu Desnoyers
Date: Mon May 03 2021 - 09:50:41 EST


----- On May 1, 2021, at 9:11 AM, rostedt rostedt@xxxxxxxxxxx wrote:

> On Sat, 1 May 2021 09:29:41 +0000
> <Peter.Enderborg@xxxxxxxx> wrote:
>
>> On 4/30/21 7:48 PM, Eric W. Biederman wrote:
>> > Peter Enderborg <peter.enderborg@xxxxxxxx> writes:
>> >
>> >> This is the peer functions to task_rename and task_newtask.
>> >> With this we get hole "life-cycle" of task and can easily
>> >> see short livied task and their exit status.
>> > This patch is incorrect. The location you are dealing with is not part
>> > of task exit. The location you have instrumented is part of reaping a
>> > task which can come arbitrarily long after the task exits.
>>
>> That is what it aiming. When using this as tool for userspace you
>> would like to know when the task is done. When it no longer
>> holds any thing that might have any impact. If you think the
>> exit imply something more specific I can change the name.
>>
>> I thought exit was a good name, it is in in exit.c.
>>
>> Will the name task_done, task_finished or task_reaped work for you?
>
> I think "task_reaped" is probably the best name, and the most
> descriptive of what happened.

What would it provide that is not already available through the "sched_process_free"
tracepoint in delayed_put_task_struct ?

Thanks,

Mathieu

--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com