Re: [PATCH 4/8] x86/asm: add clear_page_nt()

[Borislav Petkov]

On Wed, Oct 14, 2020 at 01:32:55AM -0700, Ankur Arora wrote:
> This can potentially improve page-clearing bandwidth (see below for
> performance numbers for two microarchitectures where it helps and one
> where it doesn't) and can help indirectly by consuming less cache
> resources.
> 
> Any performance benefits are expected for extents larger than LLC-sized
> or more -- when we are DRAM-BW constrained rather than cache-BW
> constrained.

"potentially", "expected", I don't like those formulations. Do you have
some actual benchmark data where this shows any improvement and not
microbenchmarks only, to warrant the additional complexity?

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette