Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751745AbWBWRJL (ORCPT ); Thu, 23 Feb 2006 12:09:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751749AbWBWRJK (ORCPT ); Thu, 23 Feb 2006 12:09:10 -0500 Received: from smtp.osdl.org ([65.172.181.4]:48066 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751745AbWBWRJI (ORCPT ); Thu, 23 Feb 2006 12:09:08 -0500 Date: Thu, 23 Feb 2006 09:08:59 -0800 (PST) From: Linus Torvalds To: Arjan van de Ven cc: Andi Kleen , linux-kernel@vger.kernel.org, akpm@osdl.org, mingo@elte.hu Subject: Re: Patch to reorder functions in the vmlinux to a defined order In-Reply-To: <1140713001.4672.73.camel@laptopd505.fenrus.org> Message-ID: References: <1140700758.4672.51.camel@laptopd505.fenrus.org> <1140707358.4672.67.camel@laptopd505.fenrus.org> <200602231700.36333.ak@suse.de> <1140713001.4672.73.camel@laptopd505.fenrus.org> 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: 1616 Lines: 45 On Thu, 23 Feb 2006, Arjan van de Ven wrote: > > > > I think you would first need to move the code first for that. Currently it starts > > at 1MB, which means 1MB is already wasted of the aligned 2MB TLB entry. > > > > I wouldn't have a problem with moving the 64bit kernel to 2MB though. > > that was easy since it's a Config entry already ;) Btw, the "low TLB entry" for the direct-mapped case can't be used as a hugetlb page anyway, due to the MMU splitting it up due to the special MTRR regions, if I recall correctly. So this is probably a bigger performance win than just the difference between using one or two TLB entries. The same should be true on x86, btw. Where we should use a physical start address of 4MB for best performance. Does anybody want to run benchmarks? (Totally untested, may not boot, might physically accost your pets for all I know). Linus --- diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig index 0afec85..d2b1df8 100644 --- a/arch/i386/Kconfig +++ b/arch/i386/Kconfig @@ -715,7 +715,7 @@ config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) default "0x1000000" if CRASH_DUMP - default "0x100000" + default "0x400000" help This gives the physical address where the kernel is loaded. Normally for regular kernels this value is 0x100000 (1MB). But in the case - 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/