Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 3 Feb 2009 14:18:51 -0700
From:      Geoff Fritz <gfritz@gmail.com>
To:        freebsd-questions@freebsd.org
Subject:   Scheduling behavior when using idprio
Message-ID:  <20090203211851.GA92202@dev.null>

Next in thread | Raw E-Mail | Index | Archive | Help
I recently noticed something odd.

Whenever I have a cpu-bound process (say, piping a lot of data through
"gzip -9c") that's been given an idle priority using "idprio 31 -<PID>", I
notice that my system's overall interactive responsiveness feels peppier.
Apps seems to respond faster, screens redraw faster, web pages render
quicker, etc..

It's reminiscent of enabling the interactive real-time options in the Linux
kernel (at least, as I remember it years ago from the 2.4 days).

My system is a little long in the tooth (2GHz Athlon64, single core), so
any speed improvements are quickly noticed around here.

I was wondering if there was an explanation for my observations, or if
anyone else has seen -- or could repeat -- this.  If this is a
repeatable/known behavior, would this be a scheduler bug?  Why would
things run more smoothly only when there was a single ulta-low priority
process running?

Thanks.

-- Geoff



Want to link to this message? Use this URL: <http://docs.FreeBSD.org/cgi/mid.cgi?20090203211851.GA92202>