On Fri, Dec 6, 2019 at 7:50 PM Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > I assume it's the added "do_wakeup = 0" (not the spinlock) that ends > up having some subtle issue. Ahh, and then later that is removed, but when it is removed it also remote the wakeup before the pipe_wait(). So whatever issue that commit introduces ends up remaining. I wonder if the extra wakeups ended up hiding some other bug. We do extra wakeups on the write side too, with a "FIXME! Is this really true?" comment.. Linus