From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e2.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id lB3LX9OJ020996 for ; Mon, 3 Dec 2007 16:33:09 -0500 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v8.7) with ESMTP id lB3LX95b487448 for ; Mon, 3 Dec 2007 16:33:09 -0500 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id lB3LX8LG013012 for ; Mon, 3 Dec 2007 16:33:09 -0500 Message-ID: <47547635.7040503@linux.vnet.ibm.com> Date: Mon, 03 Dec 2007 15:33:41 -0600 From: Jon Tollefson MIME-Version: 1.0 Subject: Re: [PATCH 2/2] powerpc: make 64K huge pages more reliable References: <474CF694.8040700@us.ibm.com> <20071203020648.GF26919@localhost.localdomain> In-Reply-To: <20071203020648.GF26919@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: David Gibson Cc: linuxppc-dev , Linux Memory Management List List-ID: David Gibson wrote: > On Tue, Nov 27, 2007 at 11:03:16PM -0600, Jon Tollefson wrote: > >> This patch adds reliability to the 64K huge page option by making use of >> the PMD for 64K huge pages when base pages are 4k. So instead of a 12 >> bit pte it would be 7 bit pmd and a 5 bit pte. The pgd and pud offsets >> would continue as 9 bits and 7 bits respectively. This will allow the >> pgtable to fit in one base page. This patch would have to be applied >> after part 1. >> > > Hrm.. shouldn't we just ban 64K hugepages on a 64K base page size > setup? There's not a whole lot of point to it, after all... > Banning the base and huge page size from being the same size feels like an artificial barrier. It is probably not the most massively useful combination, but it shouldn't hurt performance. Jon -- 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