Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758310AbZKKRoF (ORCPT ); Wed, 11 Nov 2009 12:44:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758217AbZKKRoE (ORCPT ); Wed, 11 Nov 2009 12:44:04 -0500 Received: from mx1.redhat.com ([209.132.183.28]:28092 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757947AbZKKRoD (ORCPT ); Wed, 11 Nov 2009 12:44:03 -0500 From: Jeff Moyer To: Jan Kara Cc: jens.axboe@oracle.com, LKML , Chris Mason , Andrew Morton , Mike Galbraith Subject: Re: Performance regression in IO scheduler still there References: <20091026172012.GC7233@duck.suse.cz> <20091111141031.GA21511@duck.suse.cz> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Wed, 11 Nov 2009 12:43:30 -0500 In-Reply-To: <20091111141031.GA21511@duck.suse.cz> (Jan Kara's message of "Wed, 11 Nov 2009 15:10:31 +0100") Message-ID: User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 924 Lines: 25 Jan Kara writes: > Sadly, I don't see the improvement you can see :(. The numbers are the > same regardless low_latency set to 0: > 2.6.32-rc5 low_latency = 0: > 37.39 36.43 36.51 -> 36.776667 0.434920 > But my testing environment is a plain SATA drive so that probably > explains the difference... I just retested (10 runs for each kernel) on a SATA disk with no NCQ support and I could not see a difference. I'll try to dig up a disk that support NCQ. Is that what you're using for testing? Cheers, Jeff 2.6.29 2.6.32-rc6,low_latency=0 ---------------------------------- Average: 34.6648 34.4475 Pop.Std.Dev.: 0.55523 0.21981 -- 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/