Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 23 Sep 2002 09:08:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 23 Sep 2002 09:08:47 -0400 Received: from chaos.analogic.com ([204.178.40.224]:48002 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id ; Mon, 23 Sep 2002 09:08:46 -0400 Date: Mon, 23 Sep 2002 09:15:41 -0400 (EDT) From: "Richard B. Johnson" Reply-To: root@chaos.analogic.com To: Erik Andersen cc: Con Kolivas , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [BENCHMARK] Corrected gcc3.2 v gcc2.95.3 contest results In-Reply-To: <20020923124730.GA7556@codepoet.org> Message-ID: 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: 1591 Lines: 47 On Mon, 23 Sep 2002, Erik Andersen wrote: > On Mon Sep 23, 2002 at 08:30:21PM +1000, Con Kolivas wrote: > > Yes you make a very valid point and something I've been stewing over privately > > for some time. contest runs benchmarks in a fixed order with a "priming" compile > > to try and get pagecaches etc back to some sort of baseline (I've been trying > > hard to make the results accurate and repeatable). > > It would sure be nice for this sortof test if there were > some sort of a "flush-all-caches" syscall... > > -Erik I think all you need to do is reload the code-segment register and you end up flushing caches in ix86. # # This forces a cache-line refill by reloading the code-segment # segment register. This would normally slow things down. However, # if I put this at the start of a procedure that suffers a cache-line # refill within the procedure, it is possible to speed things up. # .section .text .global cflush .type cflush,@function cflush: pushl %cs # Put code segment on the stack pushl $goto # Put offset on the stack lret # Do a 'long' return (reloads cs) goto: ret .end Cheers, Dick Johnson Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips). The US military has given us many words, FUBAR, SNAFU, now ENRON. Yes, top management were graduates of West Point and Annapolis. - 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/