ATOMIC_ADD_UNLESS(9) Driver Basics ATOMIC_ADD_UNLESS(9)
NAME atomic_add_unless - add unless the number is already a given value
SYNOPSIS int atomic_add_unless(atomic_t * v, int a, int u);
ARGUMENTS v pointer of type atomic_t
a the amount to add to v...
u ...unless v is equal to u.
DESCRIPTION Atomically adds a to v, so long as v was not already u. Returns non-zero if v was not u, and zero otherwise.
COPYRIGHT Kernel Hackers Manual 2.6. November 2013 ATOMIC_ADD_UNLESS(9)