Re: [PATCH 0/3] Virtual huge zero page

From: Andi Kleen
Date: Sat Sep 29 2012 - 10:30:05 EST


On Sat, Sep 29, 2012 at 03:48:11PM +0200, Andrea Arcangeli wrote:
> On Sat, Sep 29, 2012 at 02:37:18AM +0300, Kirill A. Shutemov wrote:
> > Cons:
> > - increases TLB pressure;
>
> I generally don't like using 4k tlb entries ever. This only has the

>From theory I would also prefer the 2MB huge page.

But some numbers comparing between the two alternatives are definitely
interesting. Numbers are often better than theory.

> There would be a small cache benefit here... but even then some first
> level caches are virtually indexed IIRC (always physically tagged to

Modern x86 doesn't have virtually indexed caches.

-Andi
--
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
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