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Date: Tue, 20 Feb 2024 10:08:57 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Oleg Nesterov <oleg@redhat.com>, wenyang.linux@foxmail.com, Masami
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 <mgorman@techsingularity.net>, Peter Zijlstra <peterz@infradead.org>,
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Subject: Re: [PATCH] coredump debugging: add a tracepoint to report the
 coredumping
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On Mon, 19 Feb 2024 13:01:16 -0500
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> 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