From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id N91vg_S4DI3z for ; Thu, 29 Mar 2012 05:02:31 +0200 (CEST) Received: from holgerdanske.com (holgerdanske.com [IPv6:2001:470:0:19b::b869:801b]) by mail.saout.de (Postfix) with SMTP for ; Thu, 29 Mar 2012 05:02:30 +0200 (CEST) Received: from ::ffff:69.12.202.165 ([69.12.202.165]) by holgerdanske.com for ; Wed, 28 Mar 2012 19:56:06 -0700 Message-ID: <4F73CF46.500@holgerdanske.com> Date: Wed, 28 Mar 2012 19:56:06 -0700 From: David Christensen MIME-Version: 1.0 References: <4F6BF806.1000504@holgerdanske.com> <4F7383C2.8040007@redhat.com> In-Reply-To: <4F7383C2.8040007@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dm-crypt] LUKS/ dm-crypt/ ext4 appears to be single threaded List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dm-crypt@saout.de On 03/28/2012 02:33 PM, Milan Broz wrote: Thank you for your reply. :-) I've been trying to pay more attention, and it appears that the blocking is limited to directories (and their subdirectories) where long-lived writes are occurring (?). Am I understanding the issue correctly? Has anyone else seen this? Is "New Methods in Hard Disk Encryption" still relevant? http://clemens.endorphin.org/cryptography > You forgot to mention kernel version, it changed in various versions. $ uname -a Linux p43400e 2.6.32-5-686 #1 SMP Mon Jan 16 16:04:25 UTC 2012 i686 GNU/Linux $ sudo cryptsetup --version cryptsetup 1.1.3 $ cat /etc/debian_version 6.0.4 Are there any tunable parameters, options, alternatives, etc., that I can adjust/ change to improve parallelism with what I have? > For recent kernel 3.x, if multiple processes access the encrypted disk, > it tries to keep submitted work on cpu which submitted it (so it run in > parallel). > There are some patches to change parallel operations to another model > in dmcrypt, if you want to experiment, see > http://people.redhat.com/mpatocka/patches/kernel/dm-crypt-paralelizace/current/ > I have several performance tests, and some of these patches perhaps > appear in 3.5 kernel but it need still more work. My kernel skills are far too rusty, and I need stability/ finished product. So, I'll have to wait for those patches to get into Debian stable (or testing). David