Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757721AbXLKXob (ORCPT ); Tue, 11 Dec 2007 18:44:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757507AbXLKXoR (ORCPT ); Tue, 11 Dec 2007 18:44:17 -0500 Received: from nf-out-0910.google.com ([64.233.182.190]:23213 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756925AbXLKXoP (ORCPT ); Tue, 11 Dec 2007 18:44:15 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:in-reply-to:references:x-mailer:mime-version:content-type:content-transfer-encoding; b=tUZ4811Bl+SxIhH4ONoz5v7vf3cn0ytAMJeXuzrLjGA2446ZHtXNkCRubnQWXSMuWnDPT/FrqSPJ5G6B+CoL0SyF4kJgaFlWFMAWcuvakZPkfKWvVomp+2vrKF6LDWZQrSywHi+Hube2g/A9iC955/ZUTvKip98TyDV8MFyAd8g= Date: Wed, 12 Dec 2007 00:43:16 +0100 From: Alejandro Riveira =?UTF-8?B?RmVybsOhbmRleg==?= 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: <20071212004316.079e3a05@Varda> In-Reply-To: <475F1DC6.5090403@keyaccess.nl> References: <475F1DC6.5090403@keyaccess.nl> X-Mailer: Claws Mail 2.10.0 (GTK+ 2.12.0; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 39 El Wed, 12 Dec 2007 00:31:18 +0100 Rene Herman escribió: > 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! > > Rene. On my AMD 3800 X2 (2000MHz) ULi M1697 2.6.24-rc5 i get: cycles: out 1844674407370808, in 1844674407369087 It is not constant but variations are not significant afaics -- 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/