On 7/14/22 10:33 AM, Uros Bizjak wrote: > Use atomic_long_try_cmpxchg instead of > atomic_long_cmpxchg (*ptr, old, new) == old in __io_account_mem. > 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_try_cmpxchg implicitly assigns old *ptr value > to "old" when cmpxchg fails, enabling further code simplifications. > > No functional change intended. This will be io_uring/rsrc.c for the for-next branches, but it'll apply directly as that with a slight offset: checking file io_uring/rsrc.c Hunk #1 succeeded at 56 (offset -10448 lines). I'll do that, thanks. -- Jens Axboe
