WAIT_ON_BIT_LOCK(9)                       Driver Basics                       WAIT_ON_BIT_LOCK(9)



NAME
       wait_on_bit_lock - wait for a bit to be cleared, when wanting to set it

SYNOPSIS
       int wait_on_bit_lock(unsigned long * word, int bit, unsigned mode);

ARGUMENTS
       word
           the word being waited on, a kernel virtual address

       bit
           the bit of the word being waited on

       mode
           the task state to sleep in

DESCRIPTION
       There is a standard hashed waitqueue table for generic use. This is the part of the
       hashtable's accessor API that waits on a bit when one intends to set it, for instance,
       trying to lock bitflags. For instance, if one were to have waiters trying to set bitflag
       and waiting for it to clear before setting it, one would call wait_on_bit in threads
       waiting to be able to set the bit. One uses wait_on_bit_lock where one is waiting for the
       bit to clear with the intention of setting it, and when done, clearing it.

       Returns zero if the bit was (eventually) found to be clear and was set. Returns non-zero
       if a signal was delivered to the process and the mode allows that signal to wake the
       process.

COPYRIGHT
Kernel Hackers Manual 4.8.                 January 2017                       WAIT_ON_BIT_LOCK(9)