Re: [PATCH 7/9] migration/xbzrle: Use i386 cacheinfo.h

[Juan Quintela <quintela@redhat.com>]

Richard Henderson <richard.henderson@linaro.org> wrote:
> Perform the function selection once, and only if CONFIG_AVX512_OPT
> is enabled.  Centralize the selection to xbzrle.c, instead of
> spreading the init across 3 files.
>
> Remove xbzrle-bench.c.  The benefit of being able to benchmark
> the different implementations is less important than peeking into
> the internals of the implementation.

Agreed.  If AVX512 is not better than a plain C implementation, better
to not have it O:-)

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Juan Quintela <quintela@redhat.com>

Not queued.  It needs your other patches, I think it is better that all
teh series go through your tree.


> +static void __attribute__((constructor)) init_accel(void)
> +{
> +    unsigned info = cpuinfo_init();
> +    if (info & CPUINFO_AVX512BW) {
> +        accel_func = xbzrle_encode_buffer_avx512;
> +    } else {
> +        accel_func = xbzrle_encode_buffer_int;
> +    }
> +}

Wow.
Comparing it with previous implementation that did it by hand with asm.