qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org,
	Gerd Hoffmann <kraxel@redhat.com>, Gleb Natapov <gleb@redhat.com>,
	"Richard W.M. Jones" <rjones@redhat.com>
Subject: Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35?
Date: Wed, 04 Aug 2010 19:36:04 +0300	[thread overview]
Message-ID: <4C5996F4.6010205@redhat.com> (raw)
In-Reply-To: <4C5995B4.90505@redhat.com>

  On 08/04/2010 07:30 PM, Avi Kivity wrote:
>  On 08/04/2010 04:52 PM, Anthony Liguori wrote:
>>>>
>>> This is not like DMA event if done in chunks and chunks can be pretty
>>> big. The code that dials with copying may temporary unmap some pci
>>> devices to have more space there.
>>
>>
>> That's a bit complicated because SeaBIOS is managing the PCI devices 
>> whereas the kernel code is running as an option rom.  I don't know 
>> the BIOS PCI interfaces well so I don't know how doable this is.
>>
>> Maybe we're just being too fancy here.
>>
>> We could rewrite -kernel/-append/-initrd to just generate a floppy 
>> image in RAM, and just boot from floppy.
>
> How could this work?  the RAM belongs to SeaBIOS immediately after 
> reset, it would just scribble over it.  Or worse, not scribble on it 
> until some date in the future.
>
> -kernel data has to find its way to memory after the bios gives 
> control to some optionrom.  An alternative would be to embed knowledge 
> of -kernel in seabios, but I don't think it's a good one.
>

Oh, you meant host RAM, not guest RAM.  Disregard.

This is basically my suggestion to libguestfs: instead of generating an 
initrd, generate a bootable cdrom, and boot from that.  The result is 
faster and has a smaller memory footprint.  Everyone wins.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

  reply	other threads:[~2010-08-04 16:36 UTC|newest]

Thread overview: 151+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-08-03 11:13 [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35? Richard W.M. Jones
2010-08-03 11:33 ` Gleb Natapov
2010-08-03 12:10   ` Richard W.M. Jones
2010-08-03 12:37     ` Gleb Natapov
2010-08-03 12:48       ` Richard W.M. Jones
2010-08-03 13:19         ` Avi Kivity
2010-08-03 14:05           ` Richard W.M. Jones
2010-08-03 14:38             ` Avi Kivity
2010-08-03 14:53               ` Richard W.M. Jones
2010-08-03 16:10                 ` Avi Kivity
2010-08-03 16:28                   ` Richard W.M. Jones
2010-08-03 16:44                     ` Avi Kivity
2010-08-03 16:46                       ` Anthony Liguori
2010-08-03 16:50                         ` Avi Kivity
2010-08-03 16:53                           ` Anthony Liguori
2010-08-03 17:01                             ` Avi Kivity
2010-08-03 17:42                               ` Anthony Liguori
2010-08-03 17:58                                 ` Avi Kivity
2010-08-03 18:11                                   ` Richard W.M. Jones
2010-08-03 18:26                                   ` Anthony Liguori
2010-08-03 18:43                                     ` Avi Kivity
2010-08-03 18:47                                       ` Avi Kivity
2010-08-03 18:55                                       ` Anthony Liguori
2010-08-03 19:00                                         ` Avi Kivity
2010-08-03 19:05                                       ` Gleb Natapov
2010-08-03 19:09                                         ` Avi Kivity
2010-08-03 19:15                                         ` Anthony Liguori
2010-08-03 19:24                                           ` Avi Kivity
2010-08-03 19:38                                             ` Anthony Liguori
2010-08-03 19:41                                               ` Avi Kivity
2010-08-03 19:47                                                 ` Anthony Liguori
2010-08-04  5:47                                                   ` Avi Kivity
2010-08-03 21:24                                                 ` Gerd Hoffmann
2010-08-03 21:20                                             ` Gerd Hoffmann
2010-08-04  5:53                                               ` Avi Kivity
2010-08-04  7:56                                                 ` Gerd Hoffmann
2010-08-04  8:17                                                   ` Avi Kivity
2010-08-04  8:43                                                     ` Gleb Natapov
2010-08-04  9:22                                                     ` Gerd Hoffmann
2010-08-04 13:04                                                     ` Anthony Liguori
2010-08-04 13:07                                                       ` Gleb Natapov
2010-08-04 13:15                                                         ` Anthony Liguori
2010-08-04 13:24                                                           ` Richard W.M. Jones
2010-08-04 13:26                                                             ` Gleb Natapov
2010-08-04 14:22                                                               ` Anthony Liguori
2010-08-04 14:38                                                                 ` Gleb Natapov
2010-08-04 14:50                                                                   ` Anthony Liguori
2010-08-04 15:01                                                                     ` Gleb Natapov
2010-08-04 15:07                                                                       ` Anthony Liguori
2010-08-04 15:15                                                                         ` Gleb Natapov
2010-08-04 22:41                                                                       ` Kevin O'Connor
2010-08-04 16:26                                                             ` Avi Kivity
2010-08-04 13:34                                                           ` Gleb Natapov
2010-08-04 13:52                                                             ` Anthony Liguori
2010-08-04 14:00                                                               ` Gleb Natapov
2010-08-04 14:14                                                                 ` Anthony Liguori
2010-08-04 14:36                                                                   ` Gleb Natapov
2010-08-04 14:22                                                                 ` Paolo Bonzini
2010-08-04 14:39                                                                   ` Anthony Liguori
2010-08-04 16:33                                                                     ` Avi Kivity
2010-08-04 16:30                                                               ` Avi Kivity
2010-08-04 16:36                                                                 ` Avi Kivity [this message]
2010-08-04 16:44                                                                   ` Anthony Liguori
2010-08-04 16:52                                                                     ` Avi Kivity
2010-08-04 17:37                                                                     ` Gleb Natapov
2010-08-05  7:28                                                                     ` Gerd Hoffmann
2010-08-05  7:34                                                                       ` Gleb Natapov
2010-08-05  7:56                                                                         ` Avi Kivity
2010-08-05  7:59                                                                           ` Gleb Natapov
2010-08-05  8:45                                                                             ` Avi Kivity
2010-08-05  8:48                                                                               ` Gleb Natapov
2010-08-05 13:43                                                                       ` Anthony Liguori
2010-08-04 16:45                                                                   ` Alexander Graf
2010-08-04 16:54                                                                     ` Avi Kivity
2010-08-04 17:01                                                                       ` Alexander Graf
2010-08-04 17:14                                                                         ` Avi Kivity
2010-08-04 17:27                                                                           ` Alexander Graf
2010-08-04 17:34                                                                             ` Avi Kivity
2010-08-04 20:06                                                                               ` David S. Ahern
2010-08-04 20:16                                                                                 ` Richard W.M. Jones
2010-08-05  2:38                                                                                 ` Avi Kivity
2010-08-04 17:26                                                                     ` Anthony Liguori
2010-08-04 17:31                                                                       ` Alexander Graf
2010-08-04 17:35                                                                         ` Avi Kivity
2010-08-04 17:36                                                                         ` Anthony Liguori
2010-08-04 17:36                                                                           ` Alexander Graf
2010-08-04 17:46                                                                   ` Richard W.M. Jones
2010-08-04 17:50                                                                     ` Avi Kivity
2010-08-04 18:13                                                                     ` Alexander Graf
2010-08-04 18:16                                                                       ` Anthony Liguori
2010-08-04 18:18                                                                         ` Alexander Graf
2010-08-04 18:19                                                                         ` Avi Kivity
2010-08-04 18:18                                                                       ` Avi Kivity
2010-08-04 16:42                                                                 ` Anthony Liguori
2010-08-04 13:22                                                         ` Richard W.M. Jones
2010-08-04 13:29                                                           ` Gleb Natapov
2010-08-04 16:25                                                       ` Avi Kivity
2010-08-03 22:06                                             ` Richard W.M. Jones
2010-08-04  5:54                                               ` Avi Kivity
2010-08-04  9:24                                                 ` Richard W.M. Jones
2010-08-04  9:27                                                   ` Gleb Natapov
2010-08-04  9:52                                                   ` Avi Kivity
2010-08-04 11:33                                                     ` Richard W.M. Jones
2010-08-04 11:36                                                       ` Avi Kivity
2010-08-04 12:07                                                       ` Gleb Natapov
2010-08-04 12:59                                                   ` Anthony Liguori
2010-08-03 19:26                                           ` Gleb Natapov
2010-08-03 19:13                                       ` Richard W.M. Jones
2010-08-03 19:17                                         ` Gleb Natapov
2010-08-03 19:19                                         ` Anthony Liguori
2010-08-03 19:22                                         ` Avi Kivity
2010-08-03 20:00                                           ` Richard W.M. Jones
2010-08-03 20:49                                             ` Anthony Liguori
2010-08-03 21:13                                               ` Paolo Bonzini
2010-08-03 21:34                                                 ` Anthony Liguori
2010-08-04  7:57                                                   ` Paolo Bonzini
2010-08-04  8:19                                                     ` Avi Kivity
2010-08-04 12:53                                                     ` Anthony Liguori
2010-08-04 16:44                                                       ` Avi Kivity
2010-08-04 16:46                                                         ` Anthony Liguori
2010-08-04 16:48                                                           ` Alexander Graf
2010-08-04 16:49                                                             ` Anthony Liguori
2010-08-04 16:51                                                               ` Alexander Graf
2010-08-04 17:01                                                               ` Paolo Bonzini
2010-08-04 17:19                                                                 ` Avi Kivity
2010-08-04 17:25                                                                   ` Alexander Graf
2010-08-04 17:27                                                                   ` Anthony Liguori
2010-08-04 17:37                                                                     ` Avi Kivity
2010-08-04 17:53                                                                       ` Anthony Liguori
2010-08-04 18:05                                                                         ` Alexander Graf
2010-08-04  5:56                                               ` Avi Kivity
2010-08-04  1:17                                             ` Jamie Lokier
2010-08-04  8:21                                         ` Avi Kivity
2010-08-04 14:51                                       ` David S. Ahern
2010-08-04 14:57                                         ` Anthony Liguori
2010-08-04 15:25                                           ` Gleb Natapov
2010-08-04 15:31                                             ` Alexander Graf
2010-08-04 15:48                                               ` Gleb Natapov
2010-08-04 15:59                                                 ` Alexander Graf
2010-08-04 16:08                                                   ` Gleb Natapov
2010-08-04 16:48                                                     ` Avi Kivity
2010-08-04 23:17                                             ` Kevin O'Connor
2010-08-05  5:26                                               ` Gleb Natapov
2010-08-03 16:56                           ` Anthony Liguori
2010-08-03 16:48                       ` Avi Kivity
2010-08-03 17:00                         ` Richard W.M. Jones
2010-08-03 17:05                           ` Avi Kivity
2010-08-03 16:56                       ` Richard W.M. Jones
2010-08-03 17:08                         ` Avi Kivity
2010-08-03 16:39                 ` Anthony Liguori
2010-08-03 16:43                   ` Richard W.M. Jones

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=4C5996F4.6010205@redhat.com \
    --to=avi@redhat.com \
    --cc=anthony@codemonkey.ws \
    --cc=gleb@redhat.com \
    --cc=kraxel@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=qemu-devel@nongnu.org \
    --cc=rjones@redhat.com \
    /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).