From: Andi Kleen <ak@linux.intel.com>
To: Mikulas Patocka <mpatocka@redhat.com>
Cc: device-mapper development <dm-devel@redhat.com>,
herbert@gondor.hengli.com.au, linux-kernel@vger.kernel.org,
agk@redhat.com
Subject: Re: [dm-devel] [PATCH] DM-CRYPT: Scale to multiple CPUs
Date: Tue, 01 Jun 2010 08:40:46 +0200 [thread overview]
Message-ID: <4C04AB6E.1080305@linux.intel.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1005312239520.6372@hs20-bc2-1.build.redhat.com>
, Mikulas Patocka wrote:
> Questions:
>
> If you are optimizing it,
>
> 1) why don't you optimize it in such a way that if one CPU submits
> requests, the crypto work is spread among all the CPUs? Currently it
> spreads the work only if different CPUs submit it.
This case is only useful with very slow CPUs and is handled by pcrypt
in theory
(but I haven't tested it)
>
> 2) why not optimize software async crypto daemon (crypt/cryptd.c) instead
> of dm-crypt, so that all kernel subsystems can actually take advantage of
> those multi-CPU optimizations, not just dm-crypt?
Normally most subsystems are multi-CPU already, unless they limit
themselves artitifically like dm-crypt.
For dm-crypt would be wasteful to funnel everything through two single CPU threads just
to spread it out again. That is why I also used per CPU IO threads too.
-Andi
next prev parent reply other threads:[~2010-06-01 6:40 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-31 16:04 [PATCH] DM-CRYPT: Scale to multiple CPUs 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
2010-05-31 17:22 ` [dm-devel] " Milan Broz
2010-05-31 17:42 ` Andi Kleen
2010-05-31 18:10 ` Milan Broz
2010-05-31 18:27 ` Andi Kleen
2010-05-31 18:55 ` Milan Broz
2010-05-31 19:04 ` Andi Kleen
2010-05-31 22:07 ` Herbert Xu
2010-05-31 22:07 ` Herbert Xu
2010-06-01 1:46 ` huang ying
2010-06-01 1:46 ` huang ying
2010-06-01 2:39 ` Mikulas Patocka
2010-06-01 2:44 ` Mikulas Patocka
2010-06-01 4:39 ` Herbert Xu
2010-06-01 4:39 ` Herbert Xu
2010-06-02 5:10 ` Mikulas Patocka
2010-06-02 5:14 ` Herbert Xu
2010-06-02 5:14 ` Herbert Xu
2010-06-02 5:25 ` Mikulas Patocka
2010-06-02 6:07 ` Herbert Xu
2010-06-02 6:07 ` Herbert Xu
2010-06-02 6:30 ` Steffen Klassert
2010-06-02 6:30 ` Steffen Klassert
2010-06-02 7:07 ` Herbert Xu
2010-06-02 7:07 ` Herbert Xu
2010-06-02 7:51 ` Andi Kleen
2010-06-01 6:40 ` Andi Kleen [this message]
2010-06-02 5:15 ` Mikulas Patocka
2010-06-02 5:20 ` Herbert Xu
2010-06-02 5:20 ` Herbert Xu
2010-06-02 7:53 ` Andi Kleen
2010-06-02 10:20 ` Herbert Xu
2010-06-02 10:20 ` Herbert Xu
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