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.
