From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Mosberger-Tang" Date: Wed, 26 Mar 2008 00:34:13 +0000 Subject: Re: larger default page sizes... Message-Id: List-Id: References: <20080324.144356.104645106.davem@davemloft.net> <20080325.162244.61337214.davem@davemloft.net> <87tziu5q37.wl%peter@chubb.wattle.id.au> In-Reply-To: <87tziu5q37.wl%peter@chubb.wattle.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Peter Chubb Cc: David Miller , clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, torvalds@linux-foundation.org, ianw@gelato.unsw.edu.au On Tue, Mar 25, 2008 at 5:41 PM, Peter Chubb wrote: > The main issue is that, at least on Itanium, you have to turn off the hardware > page table walker for hugepages if you want to mix superpages and > standard pages in the same region. (The long format VHPT isn't the > panacea we'd like it to be because the hash function it uses depends > on the page size). Why not just repeat the PTEs for super-pages? That won't work for huge pages, but for superpages that are a reasonable multiple (e.g., 16-times) the base-page size, it should work nicely. --david -- Mosberger Consulting LLC, http://www.mosberger-consulting.com/