Hi, there are several cases where wait queues are used in: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/smb/client/smbdirect.c and https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/smb/server/transport_rdma.c I'm a bit confused because we the use mixed use of wake_up(), wake_up_interruptible() and wake_up_interruptible_all() On the wait side the following are used wait_event(), wait_event_interruptible() and wait_event_interruptible_timeout() The documentation of all wait_event_* macros say 'wake_up()' should be used. And there's no documentation on the various wake_up_* macros. I guess I understand the difference between wait_event() and wait_event_interruptible(), the first ignores any signal even kill and the 2nd returns -ERESTARTSYS on any signal. I'm wondering if using wait_event_killable() should be preferred instead of wait_event() in order to prevent processes in state D hanging forever. For some wait queues it would be desired that only a single waiter is woken, so it can make good forward progress, so maybe some wait_event_*_exclusive() would be useful for this. As far as I understand the difference between wake_up() and wake_up_all() is that the first stops after the first waiter with WQ_FLAG_EXCLUSIVE. and wake_up_all() wakes all waiters (useful for error conditions, which all waiters should handle immediately. But I don't understand the difference between wake_up() and wake_up_interruptible(). My best guess would be that wake_up_interruptible() would not wake waiters using wait_event(), but only waiters using wait_event_interruptible() or any other version that includes TASK_INTERRUPTIBLE. So I guess we never want to use wake_up_interruptible(), but always wake_up() or wake_up_all() instead... It would be great if the documentation of the wake_up macros and their interaction with the wait_event macros could be improved. Any hints are highly welcome :-) Thanks! metze
