Red Hat Bugzilla – Bug 113433
Kernel 2.6.1 poor performance, high cpu-load
Last modified: 2015-01-04 17:04:16 EST
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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):
Steps to Reproduce:
1. Install kernel 2.6.1
2. Run X apps.
Created attachment 96950 [details]
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.
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.