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Commit e6b5c082 authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Jens Axboe
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percpu-rw-semaphore: fix documentation typos 



One more patch for this thing, fixing some typos in the documentation.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3eab7315

Documentation/percpu-rw-semaphore.txt

+2 −2
Original line number Original line Diff line number Diff line
@@ -9,10 +9,10 @@ cores take the lock for reading, the cache line containing the semaphore 
is bouncing between L1 caches of the cores, causing performance

is bouncing between L1 caches of the cores, causing performance

degradation.

degradation.





Locking for reading it very fast, it uses RCU and it avoids any atomic

Locking for reading is very fast, it uses RCU and it avoids any atomic

instruction in the lock and unlock path. On the other hand, locking for

instruction in the lock and unlock path. On the other hand, locking for

writing is very expensive, it calls synchronize_rcu() that can take

writing is very expensive, it calls synchronize_rcu() that can take

hundreds of microseconds.

hundreds of milliseconds.





The lock is declared with "struct percpu_rw_semaphore" type.

The lock is declared with "struct percpu_rw_semaphore" type.

The lock is initialized percpu_init_rwsem, it returns 0 on success and

The lock is initialized percpu_init_rwsem, it returns 0 on success and