Re: x86 Page Sizes

Steven Cole (elenstev@mesatop.com)
27 Jun 2002 08:26:07 -0600


On Thu, 2002-06-27 at 00:35, Peter Svensson wrote:
> On 26 Jun 2002, Robert Love wrote:
>
> > Kernel has 4K pages in user and kernel space. It is the same address
> > space and segment, just uses MMU protection.
> >
> > x86 does 4K pages.
>
> The x86 cpus can use 4K or 4M pages in the hardware. The 4M pages are
> restricted to the kernel in Linux due to various problems. This has been
> discussed on this list a while ago. The thread was called "Have the 2.4
> kernel memory management problems on large machines been fixed?" the last
> time around.
>
> 4M pages are useful to minimize tlb misses which can be costly for some
> algorithms.
>
> Peter

In addition to that thread, you might want to read the paper "Multiple
Page Size Support in the Linux Kernel", pages 573-593 in the Proceedings
of the Ottawa Linux Symposium which you can download from here:

http://www.linuxsymposium.org/2002/

If you're on a slow connection, be forewarned that it is a 631 page pdf,
but thankfully it's compressed.

Steven

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/