Re: [PATCH] x86/ioperm: Use atomic64_inc_return() in ksys_ioperm()
From: Dave Hansen
Date: Thu Oct 24 2024 - 11:21:12 EST
On 10/7/24 01:33, Uros Bizjak wrote:
> Use atomic64_inc_return(&ref) instead of atomic64_add_return(1, &ref)
> to use optimized implementation and ease register pressure around
> the primitive for targets that implement optimized variant.
Ease register pressure at the end of a syscall?
I'll accept that we're doing this just as a matter of hygiene. But it's
a stretch to say there are any performance concerns whatsoever at the
end of the ioperm() syscall.
So what is the real reason for this patch?