Re: Very poor performance with 2.6.4

From: Andreas Hartmann
Date: Mon Mar 29 2004 - 01:20:01 EST

Andrew Morton wrote:
Andreas Hartmann <andihartmann@xxxxxxxxxx> wrote:

I tested kernel 2.6.4. While compiling kdelibs and kdebase, I felt, that
kernel 2.6 seems to be slower than 2.4.25.

So I did some tests to compare the performance directly. Therefore I
rebooted for everey test in init 2 (no X).

I locally compiled 2.6.5rc2 3 times under 2.6.4 and under 2.4.25 on a
reiserfs LVM partition, which resides onto a IDE HD (using DMA) and got
the following result:

In the middle, compiling under kernel 2.6.4 tooks 9.3% more real time than
under 2.4.25.
The user-processortime is about the same, but the system-processortime is
under 2.6.4 32.9% higher than under 2.4.25.

Try mounting your reiserfs filesystems with the `-o nolargeio=1' option.

This didn't help.

If that doesn't help, please run a comparative kernel profile. See

I'll do this next.

Andreas Hartmann
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