Bug 113433 - Kernel 2.6.1 poor performance, high cpu-load
Summary: Kernel 2.6.1 poor performance, high cpu-load
Alias: None
Product: Fedora
Classification: Fedora
Component: kernel (Show other bugs)
(Show other bugs)
Version: rawhide
Hardware: i386 Linux
Target Milestone: ---
Assignee: Dave Jones
QA Contact: Brian Brock
Depends On:
TreeView+ depends on / blocked
Reported: 2004-01-13 21:17 UTC by Ralph Jacobs
Modified: 2015-01-04 22:04 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2004-11-27 23:38:38 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
dmesg output (9.73 KB, text/plain)
2004-01-13 21:19 UTC, Ralph Jacobs
no flags Details

Description Ralph Jacobs 2004-01-13 21:17:59 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i586; en-US; rv:1.4.1)

Description of problem:
I've installed kernel 2.6.1 from fedora-devel on fedora core 1 by
using the i586 RPM (I'm on a AMD K6-II 380 MHz). The kernel seems to
boot normally, so does the rest of fedora. But the overall performance
with XFree86 is very poor, cpu-usage by XFree86 is excessive: with a
couple of apps opened (Mozilla, Evolution, XMMS, BitTorrent) it uses
~18-40% constantly. XMMS also has a constant minimum cpu-usage of
~10%. Overall, the system feels very sluggish now and total cpu-usage
never really drops below ~40%. 

With the standard fedora 2.4 kernel I have absolutely no problems,
performance is much better under the same circumstances.

I've had kernel 2.6 on this box before (compiled it myself), when I
was still running Debian and had no problems (even a performance

I've noticed a couple of errors in the kernel log (see attachment).
The modprobe errors don't seem that bad to me, they're sound-related,
but that works. Could it have to do with the ReiserFS warnings?

Again, nothing seems really broken, all hardware works etc., the
performance is just really poor compared to 2.4 and vanilla 2.6 (on

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Install kernel 2.6.1
2. Run X apps.

Additional info:

Comment 1 Ralph Jacobs 2004-01-13 21:19:26 UTC
Created attachment 96950 [details]
dmesg output

Comment 2 Dave Jones 2004-01-14 03:47:39 UTC
Right now theres a lot of debugging stuff turned on to catch any
problems early. Some of the heavier stuff could be turned off though.
I'll switch off the most performance impacting debugging feature for
the next build, (1.41 or above)

The reiserfs checking will slow things down somewhat, but not
dramatically. That too will get turned off eventually.

Comment 3 Ralph Jacobs 2004-01-14 13:00:33 UTC
Thank you for clearing that up, Dave. I've compiled 2.6.1 (vanilla)
myself this morning, and, indeed, performance is how it should be.

I'll keep an eye out for the newer versions.

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