public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Andrew Theurer <habanero@linux.vnet.ibm.com>
To: Avi Kivity <avi@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>, kvm-devel <kvm@vger.kernel.org>
Subject: Re: KVM performance vs. Xen
Date: Thu, 30 Apr 2009 09:04:22 -0500	[thread overview]
Message-ID: <49F9AFE6.8010704@linux.vnet.ibm.com> (raw)
In-Reply-To: <49F9AEC0.2060909@redhat.com>

Avi Kivity wrote:
> Anthony Liguori wrote:
>> Avi Kivity wrote:
>>>>
>>>> 1) I'm seeing about 2.3% in scheduler functions [that I recognize].
>>>> Does that seems a bit excessive?
>>>
>>> Yes, it is.  If there is a lot of I/O, this might be due to the 
>>> thread pool used for I/O.
>>
>> This is why I wrote the linux-aio patch.  It only reduced CPU 
>> consumption by about 2% although I'm not sure if that's absolute or 
>> relative.  Andrew?
If  I recall correctly, it was 2.4% and relative.  But with 2.3% in 
scheduler functions, that's what I expected.
>
> Was that before or after the entire path was made copyless?
If this is referring to the preadv/writev support, no, I have not tested 
with that.

-Andrew



  reply	other threads:[~2009-04-30 14:04 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-29 14:41 KVM performance vs. Xen Andrew Theurer
2009-04-29 15:20 ` Nakajima, Jun
2009-04-29 15:33   ` Andrew Theurer
2009-04-30  8:56 ` Avi Kivity
2009-04-30 12:49   ` Andrew Theurer
2009-04-30 13:02     ` Avi Kivity
2009-04-30 13:44       ` Andrew Theurer
2009-04-30 13:47         ` Anthony Liguori
2009-04-30 13:52         ` Avi Kivity
2009-04-30 13:45   ` Anthony Liguori
2009-04-30 13:53     ` Avi Kivity
2009-04-30 15:08       ` Anthony Liguori
2009-04-30 13:59     ` Avi Kivity
2009-04-30 14:04       ` Andrew Theurer [this message]
2009-04-30 15:11         ` Anthony Liguori
2009-04-30 15:19           ` Avi Kivity
2009-04-30 15:59             ` Anthony Liguori
2009-05-01  0:40             ` Andrew Theurer
2009-05-03 16:20               ` Avi Kivity
2009-04-30 15:09       ` Anthony Liguori
2009-04-30 16:41   ` Marcelo Tosatti

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=49F9AFE6.8010704@linux.vnet.ibm.com \
    --to=habanero@linux.vnet.ibm.com \
    --cc=anthony@codemonkey.ws \
    --cc=avi@redhat.com \
    --cc=kvm@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