Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754760AbYCXWTn (ORCPT ); Mon, 24 Mar 2008 18:19:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753439AbYCXWTa (ORCPT ); Mon, 24 Mar 2008 18:19:30 -0400 Received: from sovereign.computergmbh.de ([85.214.69.204]:58313 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753191AbYCXWT3 (ORCPT ); Mon, 24 Mar 2008 18:19:29 -0400 Date: Mon, 24 Mar 2008 23:19:28 +0100 (CET) From: Jan Engelhardt To: linux-crypto@vger.kernel.org cc: Linux Kernel Mailing List Subject: strange crypto speeds, sort of Message-ID: User-Agent: Alpine 1.10 (LNX 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1275 Lines: 31 Hi, How come reading a file from a filesystem on an encrypted block device is faster than reading the encrypted block device itself? Linux home 2.6.23.17-rt #1 SMP PREEMPT RT 2007/10/26 14:17:15 UTC i686 athlon i386 GNU/Linux cryptsetup 1.0.5 /home # echo 3 >/proc/sys/vm/drop_caches /home # dd_rescue foo /dev/null ... Summary for foo -> /dev/null: dd_rescue: (warning): /dev/null (120704.0k): Invalid argument! dd_rescue: (info): ipos: 120704.0k, opos: 120704.0k, xferd: 120704.0k errs: 0, errxfer: 0.0k, succxfer: 120704.0k +curr.rate: 8728kB/s, avg.rate: 13482kB/s, avg.load: 7.1% /home # echo 3 >/proc/sys/vm/drop_caches /home # dd_rescue /dev/mapper/home /dev/null ... Summary for /dev/mapper/home -> /dev/null: dd_rescue: (info): ipos: 21504.0k, opos: 21504.0k, xferd: 21504.0k errs: 0, errxfer: 0.0k, succxfer: 21504.0k +curr.rate: 4291kB/s, avg.rate: 4291kB/s, avg.load: 5.8% -- 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/