Re: [PATCH 8/8] lib/raid/xor: x86: Add AVX-512 optimized xor_gen()

[Christoph Hellwig]

On Fri, Jun 26, 2026 at 07:47:31AM +0200, Christoph Hellwig wrote:
> On Thu, Jun 25, 2026 at 09:37:31PM -0700, Eric Biggers wrote:
> > +	if (IS_ENABLED(CONFIG_X86_64) && boot_cpu_has(X86_FEATURE_AVX512F) &&
> > +	    !boot_cpu_has(X86_FEATURE_PREFER_YMM)) {
> > +		/* AVX-512 will be the best; no need to try others. */
> > +		/* !PREFER_YMM excludes CPUs with overly-eager downclocking. */
> 
> Can you turn this into a single block comment using full sentences?
> Right now the two separate comments almost feel contradictory even
> if I get what you mean.  While you're at it also through in a blurb
> why we dont bother with AVX-512 (number of register, no one in the right
> mind would bother running high performance code on modern cpus in 32-bit
> mode).

Otherwise looks good, btw:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>