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

[Thomas Gleixner]

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>