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Spelling fixes for Documentation/atomic_ops.txt

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Spelling and typo fixes for Documentation/atomic_ops.txt

Signed-off-by: Adrian Bunk <bunk@stusta.de>
This commit is contained in:
Michael Hayes 2006-06-26 18:27:35 +02:00 committed by Adrian Bunk
parent 0ecbf4b5fc
commit a0ebb3ffd6
1 changed files with 14 additions and 14 deletions
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28
Documentation/atomic_ops.txt
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@ -157,13 +157,13 @@ For example, smp_mb__before_atomic_dec() can be used like so:
smp_mb__before_atomic_dec(); smp_mb__before_atomic_dec();
atomic_dec(&obj->ref_count); atomic_dec(&obj->ref_count);
It makes sure that all memory operations preceeding the atomic_dec() It makes sure that all memory operations preceding the atomic_dec()
call are strongly ordered with respect to the atomic counter call are strongly ordered with respect to the atomic counter
operation. In the above example, it guarentees that the assignment of operation. In the above example, it guarantees that the assignment of
"1" to obj->dead will be globally visible to other cpus before the "1" to obj->dead will be globally visible to other cpus before the
atomic counter decrement. atomic counter decrement.
Without the explicitl smp_mb__before_atomic_dec() call, the Without the explicit smp_mb__before_atomic_dec() call, the
implementation could legally allow the atomic counter update visible implementation could legally allow the atomic counter update visible
to other cpus before the "obj->dead = 1;" assignment. to other cpus before the "obj->dead = 1;" assignment.
@ -173,11 +173,11 @@ ordering with respect to memory operations after an atomic_dec() call
(smp_mb__{before,after}_atomic_inc()). (smp_mb__{before,after}_atomic_inc()).
A missing memory barrier in the cases where they are required by the A missing memory barrier in the cases where they are required by the
atomic_t implementation above can have disasterous results. Here is atomic_t implementation above can have disastrous results. Here is
an example, which follows a pattern occuring frequently in the Linux an example, which follows a pattern occurring frequently in the Linux
kernel. It is the use of atomic counters to implement reference kernel. It is the use of atomic counters to implement reference
counting, and it works such that once the counter falls to zero it can counting, and it works such that once the counter falls to zero it can
be guarenteed that no other entity can be accessing the object: be guaranteed that no other entity can be accessing the object:
static void obj_list_add(struct obj *obj) static void obj_list_add(struct obj *obj)
{ {
@ -291,9 +291,9 @@ to the size of an "unsigned long" C data type, and are least of that
size. The endianness of the bits within each "unsigned long" are the size. The endianness of the bits within each "unsigned long" are the
native endianness of the cpu. native endianness of the cpu.
void set_bit(unsigned long nr, volatils unsigned long *addr); void set_bit(unsigned long nr, volatile unsigned long *addr);
void clear_bit(unsigned long nr, volatils unsigned long *addr); void clear_bit(unsigned long nr, volatile unsigned long *addr);
void change_bit(unsigned long nr, volatils unsigned long *addr); void change_bit(unsigned long nr, volatile unsigned long *addr);
These routines set, clear, and change, respectively, the bit number These routines set, clear, and change, respectively, the bit number
indicated by "nr" on the bit mask pointed to by "ADDR". indicated by "nr" on the bit mask pointed to by "ADDR".
@ -301,9 +301,9 @@ indicated by "nr" on the bit mask pointed to by "ADDR".
They must execute atomically, yet there are no implicit memory barrier They must execute atomically, yet there are no implicit memory barrier
semantics required of these interfaces. semantics required of these interfaces.
int test_and_set_bit(unsigned long nr, volatils unsigned long *addr); int test_and_set_bit(unsigned long nr, volatile unsigned long *addr);
int test_and_clear_bit(unsigned long nr, volatils unsigned long *addr); int test_and_clear_bit(unsigned long nr, volatile unsigned long *addr);
int test_and_change_bit(unsigned long nr, volatils unsigned long *addr); int test_and_change_bit(unsigned long nr, volatile unsigned long *addr);
Like the above, except that these routines return a boolean which Like the above, except that these routines return a boolean which
indicates whether the changed bit was set _BEFORE_ the atomic bit indicates whether the changed bit was set _BEFORE_ the atomic bit
@ -335,7 +335,7 @@ subsequent memory operation is made visible. For example:
/* ... */; /* ... */;
obj->killed = 1; obj->killed = 1;
The implementation of test_and_set_bit() must guarentee that The implementation of test_and_set_bit() must guarantee that
"obj->dead = 1;" is visible to cpus before the atomic memory operation "obj->dead = 1;" is visible to cpus before the atomic memory operation
done by test_and_set_bit() becomes visible. Likewise, the atomic done by test_and_set_bit() becomes visible. Likewise, the atomic
memory operation done by test_and_set_bit() must become visible before memory operation done by test_and_set_bit() must become visible before
@ -474,7 +474,7 @@ Now, as far as memory barriers go, as long as spin_lock()
strictly orders all subsequent memory operations (including strictly orders all subsequent memory operations (including
the cas()) with respect to itself, things will be fine. the cas()) with respect to itself, things will be fine.
Said another way, _atomic_dec_and_lock() must guarentee that Said another way, _atomic_dec_and_lock() must guarantee that
a counter dropping to zero is never made visible before the a counter dropping to zero is never made visible before the
spinlock being acquired. spinlock being acquired.