Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752906Ab1DRWK5 (ORCPT ); Mon, 18 Apr 2011 18:10:57 -0400 Received: from one.firstfloor.org ([213.235.205.2]:35734 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752154Ab1DRWKy (ORCPT ); Mon, 18 Apr 2011 18:10:54 -0400 Date: Tue, 19 Apr 2011 00:10:51 +0200 From: Andi Kleen To: Andrew Lutomirski Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Linus Torvalds , Andi Kleen , x86 Subject: Re: [RFT] Please test rdtsc on various x86-64 hardware (app included) Message-ID: <20110418221051.GR16484@one.firstfloor.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1430 Lines: 42 I tested it on a dual Westmere-EP and a Quad Westmere-EX. Seems to pass everywhere. However I kept the default MAX_THREADS 4. Shouldn't that be increased for the large systems? I suspect the tests as written didn't really use the large systems. Dual: CPU vendor : GenuineIntel CPU model : Intel(R) Xeon(R) CPU E5640 ... CPU stepping : .. TSC flags : tsc rdtscp constant_tsc nonstop_tsc Using lfence_rdtsc because you have an Intel CPU Will test the "lfence;rdtsc" clock. Now test failed : worst error 48 with 48647928 samples Load3 test passed: margin 368 with 1013805 samples Load test passed : margin 368 with 4142659 samples Store test failed as expected: worst error 2940 with 4298473 samples Quad: CPU vendor : GenuineIntel CPU model : Intel(R) Xeon(R) CPU E7 ... CPU stepping : .. TSC flags : tsc rdtscp constant_tsc nonstop_tsc Using lfence_rdtsc because you have an Intel CPU Will test the "lfence;rdtsc" clock. Now test passed : margin 208 with 11997136 samples Load3 test passed: margin 812 with 98710 samples Load test passed : margin 208 with 1259451 samples Store test failed as expected: worst error 9284 with 1086616 samples -Andi -- 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/