Re: [PATCH] coredump debugging: add a tracepoint to report the coredumping

From: Steven Rostedt
Date: Tue Feb 20 2024 - 10:07:18 EST


On Mon, 19 Feb 2024 13:01:16 -0500
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:

> No ? Those hook on sched_process_free, which is the actual point where the
> task is freed (AFAIR after it's been a zombie and then waited for by another
> task).

Bah, you're correct. It *used to* be attached to sched_process_exit, and
the function callback still has that name. It was commit afcab63665742
("tracing: Use trace_sched_process_free() instead of exit() for pid
tracing") that changed it.
>
> AFAIU, "sched_process_exit" is issued close to the point where the task exits
> (it should not go back to userspace after that). "sched_process_free" is done
> when the task is really being removed.
>
> Between "sched_process_exit" and "sched_process_free", the task can still be
> observed by a trace analysis looking at sched and signal events: it's a zombie at
> that stage.

Right, thanks for reminding me what I did ;-) I guess I'm starting to get to "that age".

-- Steve