From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 58A0F6B005A for ; Wed, 28 Oct 2009 11:13:07 -0400 (EDT) Date: Wed, 28 Oct 2009 16:13:02 +0100 From: Andi Kleen Subject: Re: RFC: Transparent Hugepage support Message-ID: <20091028151302.GR7744@basil.fritz.box> References: <20091026185130.GC4868@random.random> <87ljiwk8el.fsf@basil.nowhere.org> <20091027193007.GA6043@random.random> <20091028042805.GJ7744@basil.fritz.box> <20091028120050.GD9640@random.random> <20091028141803.GQ7744@basil.fritz.box> <1256741656.5613.15.camel@aglitke> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1256741656.5613.15.camel@aglitke> Sender: owner-linux-mm@kvack.org To: Adam Litke Cc: Andi Kleen , Andrea Arcangeli , linux-mm@kvack.org, Marcelo Tosatti , Avi Kivity , Izik Eidus , Hugh Dickins , Nick Piggin , Andrew Morton List-ID: > PowerPC does not require specific virtual addresses for huge pages, but > does require that a consistent page size be used for each slice of the > virtual address space. Slices are 256M in size from 0 to 4G and 1TB in > size above 1TB while huge pages are 64k, 16M, or 16G. Unless the PPC > guys can work some more magic with their mmu, split_huge_page() in its > current form just plain won't work on PowerPC. That doesn't even take > into account the (already discussed) page table layout differences > between x86 and ppc: http://linux-mm.org/PageTableStructure . it simply won't be able to use Andrea's transparent code until someone fixes the MMU. Doesn't seem a disaster -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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