Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932380AbWBWSAP (ORCPT ); Thu, 23 Feb 2006 13:00:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932403AbWBWSAP (ORCPT ); Thu, 23 Feb 2006 13:00:15 -0500 Received: from baldrick.bootc.net ([83.142.228.48]:42730 "EHLO baldrick.bootc.net") by vger.kernel.org with ESMTP id S932380AbWBWSAN (ORCPT ); Thu, 23 Feb 2006 13:00:13 -0500 Message-ID: <43FDF82A.5050201@bootc.net> Date: Thu, 23 Feb 2006 18:00:10 +0000 From: Chris Boot User-Agent: Mail/News 1.5 (X11/20060114) MIME-Version: 1.0 To: Linux Kernel Subject: MD Raid 6: poor algorithm choice? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1120 Lines: 31 Hi all, [4295106.360000] raid6: int32x1 714 MB/s [4295106.381000] raid6: int32x2 742 MB/s [4295106.403000] raid6: int32x4 632 MB/s [4295106.429000] raid6: int32x8 523 MB/s [4295106.453000] raid6: mmxx1 1476 MB/s [4295106.474000] raid6: mmxx2 2500 MB/s [4295106.500000] raid6: sse1x1 1375 MB/s [4295106.521000] raid6: sse1x2 2339 MB/s [4295106.524000] raid6: using algorithm sse1x2 (2339 MB/s) [4295106.531000] md: raid6 personality registered for level 6 I just loaded the raid6 module for fun (might end up using it one day), and I was surprised at its choice of algorithm. By the messages above, I would have assumed it would choose the mmxx2 algorithm at 2500 MB/s instead of sse1x2 at the slightly slower 2339 MB/s. This is probably entirely expected behaviour, but why? Cheers, Chris -- Chris Boot bootc@bootc.net http://www.bootc.net/ - 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/