On Wed, 5 Mar 2025 00:49:09 +0100 Oleg Nesterov <oleg@xxxxxxxxxx>
>
> Of course! Again, whatever the woken writer checks in pipe_writable()
> lockless, another writer can make pipe_full() true again.
>
> But why do we care? Why do you think that the change you propose makes
Because of the hang reported.
> more sense than the fix from Prateek or the (already merged) Linus's fix?
>
See the loop in ___wait_event(),
for (;;) {
prepare_to_wait_event();
// flip
if (condition)
break;
schedule();
}
After wakeup, waiter will sleep again if condition flips false on the waker
side before waiter checks condition, even if condition is atomic, no?
