Man page 9 : wait_on_bit

wait_on_bit - wait for a bit to be cleared

int wait_on_bit(void *  word , int  bit , int (* action ) (void *), unsigned  mode );

word
    the word being waited on, a kernel virtual address

bit
    the bit of the word being waited on

action
    the function used to sleep, which may take special actions

mode
    the task state to sleep in

There is a standard hashed waitqueue table for generic use. This is the part of the hashtableAqs accessor API that waits on a bit. For instance, if one were to have waiters on a bitflag, one would call wait_on_bit in threads waiting for the bit to clear. One uses wait_on_bit where one is waiting for the bit to clear, but has no intention of setting it.