Re: [PATCH v4 10/10] x86/mm: Try to preserve old TLB entries using PCID

From: Thomas Gleixner
Date: Mon Jul 03 2017 - 06:56:58 EST

On Thu, 29 Jun 2017, Andy Lutomirski wrote:
> ping-pong between two mms on the same CPU using eventfd:
> patched: 1.22Âs
> patched, nopcid: 1.33Âs
> unpatched: 1.34Âs
> Same ping-pong, but now touch 512 pages (all zero-page to minimize
> cache misses) each iteration. dTLB misses are measured by
> dtlb_load_misses.miss_causes_a_walk:
> patched: 1.8Âs 11M dTLB misses
> patched, nopcid: 6.2Âs, 207M dTLB misses
> unpatched: 6.1Âs, 190M dTLB misses
> Reviewed-by: Nadav Amit <nadav.amit@xxxxxxxxx>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>

Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>