Re: [PATCH 07/10] crypto: Use ARCH_DMA_MINALIGN instead of ARCH_KMALLOC_MINALIGN

Linus Torvalds
2022-09-30T19:36:55Z

On Fri, Sep 30, 2022 at 11:33 AM Catalin Marinas
<catalin.marinas@arm.com> wrote:
>
> I started refreshing the series but I got stuck on having to do bouncing
> for small buffers even if when they go through the iommu (and I don't
> have the set up to test it yet).

May I suggest doing that "force bouncing" and "change kmalloc to have
a 8-byte minalign" to be the two first commits?

IOW, if we force bouncing for unaligned DMA, then that *should* mean
that allocation alignment is no longer a correctness issue, it's
purely a performance one due to the bouncing.

So then the rest of the series should be about "ok, this is actually a
hot enough allocation that I want to force alignment", and be purely
about performance, not correctness.

No?

Linus