From: Robert Hancock <hancockrwd@gmail.com>
To: Michael Monnerie <michael.monnerie@is.it-management.at>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Poor performance on cp on kernel 2.6.27.7-9-xen (openSUSE 11.1)
Date: Wed, 04 Feb 2009 19:38:22 -0600 [thread overview]
Message-ID: <498A430E.1040809@gmail.com> (raw)
In-Reply-To: <200902050208.50490@zmi.at>
Michael Monnerie wrote:
> And one last thing:
> rsync -aPv /disk1/bigfile /disk2/xxx
> That copies at max. 50MB/s, because 2 rsync tasks are started each
> taking 50% of 1 CPU - why doesn't the kernel switch the 2nd task to
> another CPU? There are 8 cpus in that system - 7 of them idle.
Usually in such cases it's because the tasks are piping data to each
other in such a way that they can't both run at the same time. In this
situation there is no point in moving one to another CPU because they're
not executing concurrently anyway.
prev parent reply other threads:[~2009-02-05 1:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-05 1:08 Poor performance on cp on kernel 2.6.27.7-9-xen (openSUSE 11.1) Michael Monnerie
2009-02-05 1:38 ` Robert Hancock [this message]
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=498A430E.1040809@gmail.com \
--to=hancockrwd@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=michael.monnerie@is.it-management.at \
/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