diff options
| author | Uros Bizjak <ubizjak@gmail.com> | 2022-11-02 08:11:47 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-02-02 22:50:07 -0800 |
| commit | 3ee2a3e7c1ca3b263c41cff81619ab1d200fadfb (patch) | |
| tree | 313524c855b5461998f72558e738053259a2c28a /init | |
| parent | 74b7046d329770ea9dd105ca321ad6abb91bdbbb (diff) | |
fs/ext4: use try_cmpxchg in ext4_update_bh_state
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
ext4_update_bh_state. x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move instruction
in front of cmpxchg).
Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.
No functional change intended.
Link: https://lkml.kernel.org/r/20221102071147.6642-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'init')
0 files changed, 0 insertions, 0 deletions