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

Catalin Marinas
2022-09-30T18:33:12Z

On Tue, Sep 20, 2022 at 05:47:33PM -0700, Isaac Manjarres wrote:
> On Mon, Jul 18, 2022 at 06:53:43PM +0100, Catalin Marinas wrote:
> > So do I but holidays get in the way ;). I plan to refresh my kmalloc
> > minalign series at the end of August.
> >
> > One significant change I have though is that now ARCH_KMALLOC_MINALIGN
> > now goes down all the way to 8 and using swiotlb bounce buffering if the
> > DMA mapping size is small.
>
> This sounds like a good idea for optimizing kmalloc's memory usage
> beyond what this series originally achieved. I'm sure a few other things
> have come up in the meantime, but I was curious to know if you had a
> chance to get back to this?

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).

I hope to post something when the merging window closes. In the
meantime, I pushed my work-in-progress patches to:

git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux devel/kmalloc-minalign-v2-wip

Apart from the iommu think, I still need to figure out whether with an
ARCH_DMA_MINALIGN of 128 we need to disable the kmalloc-192 cache (so
far I don't think it's needed). There are no additional changes to the
crypto code from the last series, I still set CRYPTO_MINALIGN to
ARCH_DMA_MINALIGN (without any other patches, crypto DMA will break; so
I need to see how it interacts with Herbert's series).

Anyway, I hope for more discussions once 6.1-rc1 is out.

--
Catalin