Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 21 Dec 2002 10:59:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 21 Dec 2002 10:59:03 -0500 Received: from [217.13.199.129] ([217.13.199.129]:51589 "EHLO server1.netdiscount.de") by vger.kernel.org with ESMTP id ; Sat, 21 Dec 2002 10:59:02 -0500 Date: Sat, 21 Dec 2002 17:07:06 +0100 From: Christian Leber To: Brian Gerst Cc: linux-kernel@vger.kernel.org Subject: Re: Intel P6 vs P7 system call performance Message-ID: <20021221160706.GA26838@core.home> References: <3E0006D2.3000907@quark.didntduck.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <3E0006D2.3000907@quark.didntduck.org> User-Agent: Mutt/1.4i X-Accept-Language: de en X-Location: Europe, Germany, Mannheim X-Operating-System: Debian GNU/Linux (sid) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1003 Lines: 32 On Wed, Dec 18, 2002 at 12:25:38AM -0500, Brian Gerst wrote: > How about this patch? Instead of making a per-cpu trampoline, write to > the msr during each context switch. This means that the stack pointer > is valid at all times, and also saves memory and a cache line bounce. I > also included some misc cleanups. Just a little bit of benchmarking: (little testprogram by Linus out of this thread) (on a AMD Duron 750) 2.5.52-bk2+sysenter-1 (Brian Gerst): igor3:~# ./a.out 187.894946 cycles (call 0xfffff000) 299.155075 cycles (int $0x80) 2.5.52-bk6: igor3:~# ./a.out 202.134535 cycles (call 0xffffe000) 299.117583 cycles (int $0x80) Not really much, but the difference is there. (I don't about other side effects) Christian Leber - 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/