Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755221AbaJXTyO (ORCPT ); Fri, 24 Oct 2014 15:54:14 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:42514 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752292AbaJXTyN (ORCPT ); Fri, 24 Oct 2014 15:54:13 -0400 To: "Michael L. Semon" Cc: linux-kernel@vger.kernel.org, "Martin K. Petersen" Subject: Re: Slow dc3dd in 3.18 on x86 From: "Martin K. Petersen" Organization: Oracle Corporation References: <544AA317.8070609@gmail.com> Date: Fri, 24 Oct 2014 15:54:08 -0400 In-Reply-To: <544AA317.8070609@gmail.com> (Michael L. Semon's message of "Fri, 24 Oct 2014 15:05:59 -0400") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Michael" == Michael L Semon writes: Michael> This week, a simple `dc3dd wipe=/dev/sda5` operation had speeds Michael> cut from 10-15 MB/s down to less than 1.8 MB/s. With this Michael> method, syncs took so long that magic SysRq keys were needed to Michael> stop the PC. A bisect let me here: That commit itself doesn't do anything. I was concerned that somehow integrity got enabled by accident and you were bogged down by checksum calculations but I see no evidence that this would be happening. Ran a few tests on ATA systems here. So I'm puzzled. Please let me know if the disk has an integrity profile in sysfs. -- Martin K. Petersen Oracle Linux Engineering -- 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/