From: "Brian J. Murrell" <brian@interlinx.bc.ca>
To: dm-crypt@saout.de
Subject: Re: [dm-crypt] multiple crypt devices not using multiple CPUs
Date: Sun, 16 Dec 2012 17:02:18 -0500 [thread overview]
Message-ID: <50CE44EA.5080009@interlinx.bc.ca> (raw)
In-Reply-To: <50CE3C33.2040900@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 910 bytes --]
On 12-12-16 04:25 PM, Milan Broz wrote:
>
> In current kernels, work keeps on cpu which submitted it.
So a single process doing parallel reads from multiple devices (I'm sure
you could guess where I'm going with this) will never see more
throughput than it would from a single device? If so, all the more
reason to get multi-core support (for a single process of course)
involved. :-/
> Please read
> http://www.saout.de/pipermail/dm-crypt/2012-July/002582.html
Yeah. I'm trying to see this "more processes" behavior but even the two
dds each running in different shells are still attacking the same core.
> (and try to run the second case with direct-io, iow add oflag=direct for dd)
oflag=direct?
# dd oflag=direct of=/dev/null if=/dev/mapper/t1-use bs=1M count=1000
dd: opening ‘/dev/null’: Invalid argument
I guess O_DIRECT it not valid for /dev/null.
Cheers,
b.
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 261 bytes --]
prev parent reply other threads:[~2012-12-16 22:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-16 21:04 [dm-crypt] multiple crypt devices not using multiple CPUs Brian J. Murrell
2012-12-16 21:25 ` Milan Broz
2012-12-16 22:02 ` Brian J. Murrell [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=50CE44EA.5080009@interlinx.bc.ca \
--to=brian@interlinx.bc.ca \
--cc=dm-crypt@saout.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.