From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 1/2] powerpc: add hugepagesz boot-time parameter Date: Wed, 28 Nov 2007 17:30:40 +0100 References: <474CF68E.1040709@us.ibm.com> <200711280826.46820.arnd@arndb.de> <20071128161201.GA10916@csn.ul.ie> In-Reply-To: <20071128161201.GA10916@csn.ul.ie> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 8BIT Content-Disposition: inline Message-Id: <200711281730.40907.arnd@arndb.de> Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: linuxppc-dev@ozlabs.org, kniht@linux.vnet.ibm.com, Linux Memory Management List List-ID: On Wednesday 28 November 2007, Mel Gorman wrote: > 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. I think you can select the page size using a hypercall on the PS3. The CPU supports any two of (64k, 1M, 16M) simultaneously. Arnd <>< -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org