On 06/24, Linus Torvalds wrote: > > That said, I'm not entirely happy with your patch.
Neither me, > The real problem, I feel, is that > > if (likely(bit_is_set)) > io_schedule(); > > anti-pattern. Without that, we wouldn't have the bug. > > Normally, we'd be TASK_RUNNING in this sequence, but because we might > skip io_schedule(), we can still be in a "sleeping" state here and be > "woken up" between that bit setting and the signal check. Ah. And now it _seems_ to me that even if io_schedule() is called try_to_wake_up() can "falsely" succed if signal_pending_state() is true, even if __schedule() won't block in this case. But I am sure I missed something else. I spent to much time reading the random code paths today, I'll return tomorrow. Oleg.
