Re: [linus:master] [iov_iter] c9eec08bac: vm-scalability.throughput -16.9% regression

Linus Torvalds
2023-11-20T16:06:55Z

On Mon, 20 Nov 2023 at 05:33, David Howells <dhowells@redhat.com> wrote:
>
> So what, if anything, should I change?

I don't think you need to worry about this.

Not that I like ignoring kernel robot report performance regressions,
because they've often been useful to find unexpected issues. But this
one seems to clearly be just a random code choice issue by the
compiler, and be very CPU-specific anyway.

We'll figure out some good way to make memcpy() a bit more reliable
wrt the code it generates, but it's not the iov_iter code that should
worry about it.

Linus