Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756793AbXLLBa3 (ORCPT ); Tue, 11 Dec 2007 20:30:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751343AbXLLBaV (ORCPT ); Tue, 11 Dec 2007 20:30:21 -0500 Received: from agminet01.oracle.com ([141.146.126.228]:12531 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751147AbXLLBaU (ORCPT ); Tue, 11 Dec 2007 20:30:20 -0500 Date: Tue, 11 Dec 2007 17:28:28 -0800 From: Randy Dunlap To: Rene Herman Cc: Linux Kernel , dpreed@reed.com, Alan Cox , pavel@ucw.cz, andi@firstfloor.org, rol@as2917.net, Krzysztof Halasa , david@davidnewall.com, hpa@zytor.com, john@stoffel.org, linux-os@analogic.com Subject: Re: [RFT] Port 0x80 I/O speed Message-Id: <20071211172828.50e68804.randy.dunlap@oracle.com> In-Reply-To: <475F1DC6.5090403@keyaccess.nl> References: <475F1DC6.5090403@keyaccess.nl> Organization: Oracle Linux Eng. X-Mailer: Sylpheed 2.4.7 (GTK+ 2.8.10; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2072 Lines: 65 On Wed, 12 Dec 2007 00:31:18 +0100 Rene Herman wrote: > Good day. > > Would some people on x86 (both 32 and 64) be kind enough to compile and run > the attached program? This is about testing how long I/O port access to port > 0x80 takes. It measures in CPU cycles so CPU speed is crucial in reporting. > > Posted a previous incarnation of this before, buried in the outb 0x80 thread > which had a serialising problem. This one should as far as I can see measure > the right thing though. Please yell if you disagree... > > For me, on a Duron 1300 (AMD756 chipset) I have a constant: > > rene@7ixe4:~/src/port80$ su -c ./port80 > cycles: out 2400, in 2400 > > and on a PII 400 (Intel 440BX chipset) a constant: > > rene@6bap:~/src/port80$ su -c ./port80 > cycles: out 553, in 251 > > Results are (mostly) independent of compiler optimisation, but testing with > an -O2 compile should be most useful. Thanks! (-m32 build on x86_64) midway:/home/rddunlap/src # ./port80 cycles: out 2702, in 1903 midway:/home/rddunlap/src # ./port80 cycles: out 2688, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2703, in 1909 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1907 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1919 midway:/home/rddunlap/src # ./port80 cycles: out 2687, in 1893 midway:/home/rddunlap/src # ./port80 cycles: out 2701, in 1909 midway:/home/rddunlap/src # ./port80 cycles: out 2706, in 1906 /proc/cpuinfo says CPU speed is processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Pentium(R) D CPU 3.00GHz stepping : 4 cpu MHz : 2999.988 --- ~Randy -- 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/