wake_up_bit
Prev | Wait queues and Wake events | Next

## Name

wake_up_bit — wake up a waiter on a bit

## Synopsis

`void wake_up_bit (` | void * word,
| int bit`)`;

## Arguments

`word`

  the word being waited on, a kernel virtual address

`bit`

  the bit of the word being waited on

## Description

There is a standard hashed waitqueue table for generic use. This is the part of the hashtable's accessor API that wakes up waiters on a bit. For instance, if one were to have waiters on a bitflag, one would call `wake_up_bit` after clearing the bit.

In order for this to function properly, as it uses `waitqueue_active` internally, some kind of memory barrier must be done prior to calling this. Typically, this will be `smp_mb__after_atomic`, but in some cases where bitflags are manipulated non-atomically under a lock, one may need to use a less regular barrier, such fs/inode.c's `smp_mb`, because `spin_unlock` does not guarantee a memory barrier.

Prev | Up | Next
abort_exclusive_wait | Home | wake_up_atomic_t