[dm-crypt] LUKS/ dm-crypt/ ext4 appears to be single threaded
dpchrist at holgerdanske.com
Thu Mar 29 04:56:06 CEST 2012
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?
> 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
$ sudo cryptsetup --version
$ cat /etc/debian_version
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
> There are some patches to change parallel operations to another model
> in dmcrypt, if you want to experiment, see
> 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).
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