Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 27 Jun 2002 02:37:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 27 Jun 2002 02:37:40 -0400 Received: from k7g317-2.kam.afb.lu.se ([130.235.57.218]:6063 "EHLO cheetah.psv.nu") by vger.kernel.org with ESMTP id ; Thu, 27 Jun 2002 02:37:40 -0400 Date: Thu, 27 Jun 2002 08:35:05 +0200 (CEST) From: Peter Svensson To: Robert Love cc: Dan Sturtevant , Subject: Re: x86 Page Sizes In-Reply-To: <1025129491.1144.7.camel@icbm> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1094 Lines: 29 On 26 Jun 2002, Robert Love wrote: > Kernel has 4K pages in user and kernel space. It is the same address > space and segment, just uses MMU protection. > > x86 does 4K pages. The x86 cpus can use 4K or 4M pages in the hardware. The 4M pages are restricted to the kernel in Linux due to various problems. This has been discussed on this list a while ago. The thread was called "Have the 2.4 kernel memory management problems on large machines been fixed?" the last time around. 4M pages are useful to minimize tlb misses which can be costly for some algorithms. Peter -- Peter Svensson ! Pgp key available by finger, fingerprint: ! 8A E9 20 98 C1 FF 43 E3 07 FD B9 0A 80 72 70 AF ------------------------------------------------------------------------ Remember, Luke, your source will be with you... always... - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/