From: Milan Broz <mbroz@redhat.com>
To: dave b <db.pub.mail@gmail.com>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>,
device-mapper development <dm-devel@redhat.com>
Subject: Re: Fwd: [dm-crypt] [BUG] bad performance and system stalls when using dm-crypt
Date: Sun, 24 Oct 2010 19:05:55 +0200 [thread overview]
Message-ID: <4CC46773.2000606@redhat.com> (raw)
In-Reply-To: <AANLkTi=Hw-iU98rTjyDFAPSqqrWvzhOnE_0UBV-tMeie@mail.gmail.com>
On 10/24/2010 06:52 PM, dave b wrote:
>> So there are now several known situations when dm-crypt doesn't
>> perform as expected (another problem just appeared when using CFQ,
>> (because dm(-crypt) lost the issuing process reference)
>> see http://lkml.org/lkml/2010/10/24/59).
>
> Thank for you replying ^ ^
> I was aware with the problems and I am following Andi's dm-crypt
> per-cpu patch (I haven't applied or tested it). However, I didn't know
> about http://lkml.org/lkml/2010/10/24/59 -->
> So this may well be the root of the problem!
> Also, won't http://lkml.org/lkml/2010/10/24/59 need to be altered
> (again) to work with Andi's patch ?
CFQ related problem should be solved - probably device-mapper core
have to provide some help. (It is not only about dm-crypt,
lot of situations when IO is submitted from different internal process.
The proposed patch is not the proper and complete way how to solve it.)
For the per-cpu patch - I am waiting for replay, apparently some
additional work there is needed.
But I would like to solve it ASAP.
Milan
prev parent reply other threads:[~2010-10-24 17:05 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
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2010-10-24 16:31 ` Fwd: [dm-crypt] [BUG] bad performance and system stalls when using dm-crypt Milan Broz
2010-10-24 16:52 ` dave b
2010-10-24 17:05 ` Milan Broz [this message]
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