Messages in this thread | | | Date | Tue, 1 May 2018 15:59:24 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 2/2] sched: Introduce set_special_state() |
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On 05/01, Peter Zijlstra wrote: > > The only code I found that seems to care is ptrace_attach(), where we > wait for JOBCTL_TRAPPING to get cleared. That same function has a > comment about hiding the STOPPED -> RUNNING -> TRACED transition. So I'm > assuming it needs to observe TRACED if it observes !TRAPPING.
Yes, exactly.
> But I don't think there's enough barriers on that end to guarantee this. > Any ->state load after wait_on_bit() is, afact, free to have happened > before the ->jobctl load.
do_wait() does set_current_state() before it checks ->state or anything else.
Oleg.
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