From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 Aug 2006 09:32:02 +1000 Message-ID: <874pvw3099.peterc%peterc@gelato.unsw.edu.au> From: Peter Chubb In-Reply-To: <1156785119.5913.25.camel@localhost.localdomain> References: <20060828154413.E05721BD@localhost.localdomain> <1156785119.5913.25.camel@localhost.localdomain> MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Subject: Re: [RFC][PATCH 1/7] generic PAGE_SIZE infrastructure (v2) Sender: owner-linux-mm@kvack.org Return-Path: To: Dave Hansen Cc: Christoph Lameter , linux-mm@kvack.org List-ID: >>>>> "Dave" == Dave Hansen writes: >> > +choice > + prompt "Kernel Page Size" > + depends on >> ARCH_GENERIC_PAGE_SIZE > +config PAGE_SIZE_4KB > + bool "4KB" > + >> help > + This lets you select the page size of the kernel. For >> best 64-bit > + performance, a page size of larger than 4k is >> recommended. For best > + 32-bit compatibility on 64-bit >> architectures, a page size of 4KB > + should be selected (although >> most binaries work perfectly fine with > + a larger page size). > >> + > + 4KB For best 32-bit compatibility > + 8KB and up For best >> performance > + above 64k For kernel hackers only > + > + If you >> don't know what to do, choose 8KB (if available). > + Otherwise, >> choose 4KB. >> >> The above also would need to be genericized. Dave> That is genericized. ;) Are there some bits that don't fit ia64 Dave> well? IA64 wants 16k standard, 64k for better performance. So something that says `choose 8k if you can' doesn't really fit. And it'd be *really* nice to test larger pages --- I see ~5% improvement in streaming I/O to a suitable RAID array with 64k as opposed to 16k pages. (The full range of hardware-supported page sizes for Itanium 2 is: 4K, 8K, 16K, 64K, 256K, 1M, 4M, 16M, 64M, 256M, 1G, 4G and for Itanium 1 is: 4k, 16k, 64k, 256k, 1M, 4M, 16M, 64M, 256M) -- Dr Peter Chubb http://www.gelato.unsw.edu.au peterc AT gelato.unsw.edu.au http://www.ertos.nicta.com.au ERTOS within National ICT Australia -- 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