From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 15 Oct 2003 18:43:38 +0100 (BST) Received: from p508B51CB.dip.t-dialin.net ([IPv6:::ffff:80.139.81.203]:33736 "EHLO dea.linux-mips.net") by linux-mips.org with ESMTP id ; Wed, 15 Oct 2003 18:43:32 +0100 Received: from dea.linux-mips.net (localhost [127.0.0.1]) by dea.linux-mips.net (8.12.8/8.12.8) with ESMTP id h9FHgHNK019163; Wed, 15 Oct 2003 19:42:17 +0200 Received: (from ralf@localhost) by dea.linux-mips.net (8.12.8/8.12.8/Submit) id h9FHgGpQ019150; Wed, 15 Oct 2003 19:42:16 +0200 Date: Wed, 15 Oct 2003 19:42:16 +0200 From: Ralf Baechle To: Jun Sun Cc: "Maciej W. Rozycki" , linux-mips@linux-mips.org Subject: Re: MIPS addressing limits, Was: Re: CVS Update@-mips.org: linux Message-ID: <20031015174216.GD11276@linux-mips.org> References: <20031014132850.GA12938@linux-mips.org> <20031015145948.GB23514@linux-mips.org> <20031015101902.C8761@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031015101902.C8761@mvista.com> User-Agent: Mutt/1.4.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 3448 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Wed, Oct 15, 2003 at 10:19:02AM -0700, Jun Sun wrote: > Isn't ia64 still using 3-level page tables? Any performance data we > can infer from theirs? Very different MMU, IA64 data is hardly an indicator. And anyway, the result should be MIPS TLB refill handlers suck big chunky rocks through a straw so should be rewritten ;-) > I feel a little uneasy about ditching 3-level pagetable altogether. > Leaving all the parameters configurable, including the possiblity of > nullifying the second level and changing page size, seems to be a more > comforting thought. 3 levels are only needed if you can seriously say you're need more than 64GB of vmalloc space or processes larger than 64GB. Little need for that in the current universe though I know one institution which broke the 1TB process size limit > 5 years ago. Ralf