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| author | Uros Bizjak <ubizjak@gmail.com> | 2023-03-05 16:55:32 +0100 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-03-21 13:59:48 -0400 |
| commit | 8328e36da9cd8cb051394630e910cbb461f7e3ec (patch) | |
| tree | 35d10a2205d1f1ca0467cc06c0e27863352f8843 /kernel/trace/ftrace.c | |
| parent | bc92b9562abc831a65e505d2e675b51528d22d8b (diff) | |
ring_buffer: Use try_cmpxchg instead of cmpxchg
Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old.
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/20230305155532.5549-4-ubizjak@gmail.com
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ftrace.c')
0 files changed, 0 insertions, 0 deletions