On Thu, 8 Sep 2022 17:12:00 +0200, Uros Bizjak wrote:
> Use atomic_long_try_cmpxchg instead of
> atomic_long_cmpxchg (*ptr, old, new) == old in __sbitmap_queue_get_batch.
> 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, atomic_long_cmpxchg implicitly assigns old *ptr value to "old"
> when cmpxchg fails, enabling further code simplifications, e.g.
> an extra memory read can be avoided in the loop.
>
> [...]
Applied, thanks!
[1/1] sbitmap: Use atomic_long_try_cmpxchg in __sbitmap_queue_get_batch
commit: c35227d4e8cbc70a6622cc7cc5f8c3bff513f1fa
Best regards,
--
Jens Axboe
