Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757206AbXLLCIL (ORCPT ); Tue, 11 Dec 2007 21:08:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751810AbXLLCH4 (ORCPT ); Tue, 11 Dec 2007 21:07:56 -0500 Received: from home.nigel.suspend2.net ([203.171.70.205]:60561 "EHLO home.nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751511AbXLLCH4 (ORCPT ); Tue, 11 Dec 2007 21:07:56 -0500 Message-ID: <475F4273.80905@nigel.suspend2.net> Date: Wed, 12 Dec 2007 13:07:47 +1100 From: Nigel Cunningham Reply-To: nigel@nigel.suspend2.net User-Agent: Thunderbird 2.0.0.6 (X11/20071022) MIME-Version: 1.0 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 References: <475F1DC6.5090403@keyaccess.nl> <475F2358.6060006@nigel.suspend2.net> <475F24C1.2050807@keyaccess.nl> In-Reply-To: <475F24C1.2050807@keyaccess.nl> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1582 Lines: 54 Rene Herman wrote: > On 12-12-07 00:55, Nigel Cunningham wrote: > >> (AMD 1.8GHz Turion, running at 800MHz. ATI RS480 - Mitac 8350 mobo) >> >> nigel@home:~/Downloads$ gcc port80.c -o port80 >> nigel@home:~/Downloads$ sudo ./port80 >> cycles: out 1235, in 1207 > > Looking good. > >> nigel@home:~/Downloads$ gcc -O2 port80.c -o port80 >> nigel@home:~/Downloads$ sudo ./port80 >> cycles: out 1844674407370794, in 1844674407369408 > > Obviously not. I suppose this changes with -m32 on the GCC command line? > (sorry for missing that, I have no 64-bit machines). Yes, it does: nigel@home:~/Downloads$ gcc -m32 -o port80 port80.c nigel@home:~/Downloads$ sudo ./port80 cycles: out 1231, in 1208 nigel@home:~/Downloads$ sudo ./port80 cycles: out 1233, in 1210 Incidentally: nigel@home:~/Downloads$ processor_speed (A little script I made because my lappy does a solid lock every now and then that seems to be cpu-freq related - locking it to one frequency makes the lock far less common). Speed is now 1800000. nigel@home:~/Downloads$ sudo ./port80 cycles: out 2472, in 2505 nigel@home:~/Downloads$ sudo ./port80 cycles: out 2489, in 2515 nigel@home:~/Downloads$ sudo ./port80 cycles: out 2481, in 2503 nigel@home:~/Downloads$ sudo ./port80 cycles: out 2476, in 2507 So the same effect Maxim reported is seen here. Regards, Nigel -- 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/