lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 10 Mar 2011 08:57:30 -0800
From:	Andi Kleen <ak@...ux.intel.com>
To:	Mario 'BitKoenig' Holbe <Mario.Holbe@...Ilmenau.DE>,
	dm-crypt@...ut.de, linux-kernel@...r.kernel.org,
	Milan Broz <mbroz@...hat.com>,
	Alasdair G Kergon <agk@...hat.com>
Subject: Re: dm-crypt: Performance Regression 2.6.37 -> 2.6.38-rc8

On Tue, Mar 08, 2011 at 05:45:08PM +0100, Mario 'BitKoenig' Holbe wrote:
> Hello,
> 
> dm-crypt in 2.6.38 changed to per-CPU workqueues to increase it's
> performance by parallelizing encryption to multiple CPUs.
> This modification seems to cause (massive) performance drops for
> multiple parallel dm-crypt instances...
> 
> I'm running a 4-disk RAID0 on top of 4 independent dm-crypt(aes-xts)
> devices on a Core2Quad 3GHz. This setup did overcome the single-CPU
> limitation from previous versions and utilized all 4 cores for
> encryption.
> The throughput of this array drops from 282MB/s sustained read (dd,
> single process) with 2.6.37.3 down to 133MB/s with 2.6.38-rc8 (which

It will be better with multiple processes running on different CPUs. 
The new design is really for multiple processes.

Do you actually use dd for production or is this just a benchmark?
(if yes: newsflash: use a better benchmark)

-Andi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ