From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 13 Mar 2007 16:10:31 +1100 From: David Gibson To: Paul Mackerras Subject: Re: [PATCH] ppc: Add support for bigger page sizes than 4KB on PPC44x Message-ID: <20070313051031.GQ29506@localhost.localdomain> References: <200703122254.27087.sr@denx.de> <17910.12015.508991.966593@cargo.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <17910.12015.508991.966593@cargo.ozlabs.ibm.com> Cc: linuxppc-dev@ozlabs.org, Stefan Roese List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Mar 13, 2007 at 03:56:15PM +1100, Paul Mackerras wrote: > Stefan Roese writes: > > > +config PPC_PAGE_SHIFT > > + int "Page size (12=>4KB; 16=>64KB)" > > + default "12" > > + range 12 16 > > + help > > + The PAGE_SIZE definition. Increasing the page size may > > + improve the system performance in some dedicated cases. > > + > > + If unsure, set it to 12 (4KB). > > [snip] > > > +#else > > +#error "Unsupported PAGE_SIZE" > > +#endif > > If you only support 4k and 64k page sizes, why do you let the user > choose 13, 14 or 15 for PPC_PAGE_SHIFT? Why not just have a "64k > pages" boolean option like 64-bit powerpc does? As far as I can tell from the patch, 14 should work too (16kB pages). 13 or 15 won't, since only power-of-4 pagesizes are supported on 44x. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson