dm-devel.redhat.com archive mirror
 help / color / mirror / Atom feed
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 18:31:18 +0200	[thread overview]
Message-ID: <4CC45F56.7010305@redhat.com> (raw)
In-Reply-To: <AANLkTikqhMbW7sWbbU_we5YE9Y9U=MPUTm553AmCyH51@mail.gmail.com>

On 10/24/2010 05:32 PM, dave b wrote:
> I am forwarding this to the linux kernel mailing list to see if anyone
> is actually interested with this bug or not. I suspect that the patch
> to allow DM-CRYPT to use multiple cpus(Scale to multiple CPUs) will
> remove most of the problem but *not* all of it. As I previously was
> triggering the bug on a single core system.

Hi,
sorry for not updating the bug. We know about this.

Fix was expected to be based on top of the Andi's dm-crypt per-cpu
patch but unfortunately I found serious problems there
(see this thread http://lkml.org/lkml/2010/10/20/215 )

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).

Milan

       reply	other threads:[~2010-10-24 16:31 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <AANLkTinbeAn4ObFSb4f4znjYHGNKTMnfV7eQja+cnsLe@mail.gmail.com>
     [not found] ` <20100911065725.GA6279@fancy-poultry.org>
     [not found]   ` <AANLkTikTq=GTy-XPD6ye6kStASNL4Pa07wHhH_ABmpm1@mail.gmail.com>
     [not found]     ` <AANLkTim7RvpOcBajyqCkrBP8EW-FwNysvwuF5MaDJiFV@mail.gmail.com>
     [not found]       ` <AANLkTi=PCd1=w-mkc=Sj4EEda=PnTv0JGyV1Ysxq4ej4@mail.gmail.com>
     [not found]         ` <AANLkTikLSFFpbgX+rBR5banBygmB6rRvzMBYKfPcFPuJ@mail.gmail.com>
     [not found]           ` <4C8C9834.8060201@redhat.com>
     [not found]             ` <AANLkTi=8jJMz3f0VGwg+6P+BJEfxj6i-jBkGmqx8hCVg@mail.gmail.com>
     [not found]               ` <AANLkTinohRReVsYoetEjqAp-XrL9C2jxGgXLVnLafSUM@mail.gmail.com>
     [not found]                 ` <AANLkTikqhMbW7sWbbU_we5YE9Y9U=MPUTm553AmCyH51@mail.gmail.com>
2010-10-24 16:31                   ` Milan Broz [this message]
2010-10-24 16:52                     ` Fwd: [dm-crypt] [BUG] bad performance and system stalls when using dm-crypt dave b
2010-10-24 17:05                       ` Milan Broz

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=4CC45F56.7010305@redhat.com \
    --to=mbroz@redhat.com \
    --cc=db.pub.mail@gmail.com \
    --cc=dm-devel@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).