From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 14 Nov 2004 09:25:25 +0100 From: Andi Kleen Subject: Re: [RFC] Possible alternate 4 level pagetables? Message-ID: <20041114082525.GB16795@wotan.suse.de> References: <4196F12D.20005@yahoo.com.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4196F12D.20005@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Nick Piggin Cc: Andi Kleen , Linux Memory Management List-ID: On Sun, Nov 14, 2004 at 04:46:21PM +1100, Nick Piggin wrote: > Just looking at your 4 level page tables patch, I wondered why the extra > level isn't inserted between pgd and pmd, as that would appear to be the > least intrusive (conceptually, in the generic code). Also it maybe matches > more closely the way that the 2->3 level conversion was done. I did it the way I did to keep i386 and other archs obviously correct because their logic doesn't change at all for the three lower levels, and the highest level just hands a pointer through. Regarding intrusiveness in common code: you pretty much have to change most of of mm/memory.c, no matter what you do. Also there are overall only 7 or 8 users that really need the full scale changes, so it's not as bad as it looks. Ok there is ioremap in each architecture, but usually you can cheat for these because you know the architecture will never support 4levels. I'm sorry, but I don't see much advantage of your patches over mine. -Andi -- 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: aart@kvack.org