Subject: Re: [PATCH 1/2] powerpc: add hugepagesz boot-time parameter

From: Mel Gorman <[email-masked]>
Date: Wed, 28 Nov 2007 16:12:02 +0000

On (28/11/07 08:26), Arnd Bergmann didst pronounce:
> On Wednesday 28 November 2007, Jon Tollefson wrote:
> > This patch adds the hugepagesz boot-time parameter for ppc64 that lets 
> > you pick the size for your huge pages.  The choices available are 64K 
> > and 16M.  It defaults to 16M (previously the only choice) if nothing or 
> > an invalid choice is specified.  Tested 64K huge pages with the 
> > libhugetlbfs 1.2 release with its 'make func' and 'make stress' test 
> > invocations.
> 
> How hard would it be to add the 1MB page size that some CPUs support
> as well? On systems with small physical memory like the PS3, that
> sounds very useful to me.
> 

Does the PS3 support 1M pages in hardware? When I last looked, the magic
ibm,segment-page-sizes file that described the supported pagesizes was
missing from the device tree. In this situation, the default sizes
become 4K and 16M because no other ones are advertised.

-- 
Mel Gorman
Part-time Phd Student                          Linux Technology Center
University of Limerick                         IBM Dublin Software Lab