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| author | Thomas Gleixner <tglx@linutronix.de> | 2018-03-14 20:37:31 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-14 20:37:31 +0100 |
| commit | b0d8bef8ed805ca92eb91e86acf3ce89cbebc8ce (patch) | |
| tree | 8838391a76f0cf75ffcd31166996d03d19c580a6 /Documentation/atomic_bitops.txt | |
| parent | 82b691bedf05f258f1c86c96ee574b0d7795c0a1 (diff) | |
| parent | fc6eabbbf8ef99efed778dd5afabc83c21dba585 (diff) | |
Merge branch 'linus' into irq/core to pick up dependencies.
Diffstat (limited to 'Documentation/atomic_bitops.txt')
| -rw-r--r-- | Documentation/atomic_bitops.txt | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/Documentation/atomic_bitops.txt b/Documentation/atomic_bitops.txt index 5550bfdcce5f..be70b32c95d9 100644 --- a/Documentation/atomic_bitops.txt +++ b/Documentation/atomic_bitops.txt @@ -58,7 +58,12 @@ Like with atomic_t, the rule of thumb is: - RMW operations that have a return value are fully ordered. -Except for test_and_set_bit_lock() which has ACQUIRE semantics and + - RMW operations that are conditional are unordered on FAILURE, + otherwise the above rules apply. In the case of test_and_{}_bit() operations, + if the bit in memory is unchanged by the operation then it is deemed to have + failed. + +Except for a successful test_and_set_bit_lock() which has ACQUIRE semantics and clear_bit_unlock() which has RELEASE semantics. Since a platform only has a single means of achieving atomic operations |