Re: [PATCH] x86: only use ERMS for user copies for larger sizes

[Linus Torvalds]

On Fri, Nov 23, 2018 at 10:39 AM Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:
>
> What is memcpy_to_io even supposed to do?  Iâm guessing itâs defined as something like âcopy this data to IO space using at most long-sized writes, all aligned, and writing each byte exactly once, in order.â  That sounds... dubiously useful.

We've got hundreds of users of it, so it's fairly common..

> I could see a function that writes to aligned memory in specified-sized chunks.

We have that. It's called "__iowrite{32,64}_copy()". It has very few users.

                  Linus