From: Tomasz Chmielewski <mangoo@wpkg.org>
To: linux-kernel@vger.kernel.org
Cc: mbroz@redhat.com, Andi Kleen <andi@firstfloor.org>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] DM-CRYPT: Scale to multiple CPUs
Date: Mon, 31 May 2010 20:47:29 +0200 [thread overview]
Message-ID: <4C040441.9020107@wpkg.org> (raw)
Milan Broz wrote:
> On 05/31/2010 06:04 PM, Andi Kleen wrote:
>> DM-CRYPT: Scale to multiple CPUs
>>
>> Currently dm-crypt does all encryption work per dmcrypt mapping in a
>> single workqueue. This does not scale well when multiple CPUs
>> are submitting IO at a high rate. The single CPU running the single
>> thread cannot keep up with the encryption and encrypted IO performance
>> tanks.
>
> This is true only if encryption run on the CPU synchronously.
>
> (Usually it is high speed SSD or dm-crypt above striped RAID where
> underlying device throughput is higher than CPU encryption speed.)
Quite common to hit on a netbook/laptop with encrypted root these days,
where storage can be relatively fast when compared to the speed of one
of the cores of the (usually) multicore CPU.
--
Tomasz Chmielewski
http://wpkg.org
next reply other threads:[~2010-05-31 18:57 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-31 18:47 Tomasz Chmielewski [this message]
2010-06-01 7:21 ` [PATCH] DM-CRYPT: Scale to multiple CPUs Andi Kleen
-- strict thread matches above, loose matches on Subject: below --
2010-05-31 16:04 Andi Kleen
2010-05-31 16:04 ` Andi Kleen
2010-05-31 16:34 ` Eric Dumazet
2010-05-31 16:34 ` Eric Dumazet
2010-05-31 17:46 ` Andi Kleen
2010-05-31 17:46 ` Andi Kleen
2010-05-31 17:52 ` Eric Dumazet
2010-05-31 17:52 ` Eric Dumazet
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