Q: utrace_reset() && UTRACE_EVENT(REAP)

[Oleg Nesterov]

I'm afraid I wasn't clear again,

On 03/12, Oleg Nesterov wrote:
>
> Oh. utrace_attach_task()->utrace_add_engine() sets ->report + TIF_NOTIFY_RESUME.
> But tracehook_notify_resume() does nothing because ->utrace_flags == 0 ?
> Confused.

Perhaps this is not problem per se. But let's suppose we call, say,
utrace_control(UTRACE_STOP) later. utrace_do_stop() sees ->report == 1
and doesn't call set_notify_resume(). But TIF_NOTIFY_RESUME was already
cleared by do_notify_resume().

And again, utrace_control(UTRACE_STOP) does not set ->utrace_flags != 0
itself. But even if we called utrace_set_events(XXX) before, without
set_notify_resume() we have to wait for that XXX event, this doesn't
look right.

Oleg.