disk throughput down in 2.5.8

[Mikael Pettersson]

Is it just me or is disk I/O throughput way down in 2.5.8?

I was preparing to build 2.4.19-pre7 on a box running 2.5.8,
when I noticed that 'tar zxvf' on the kernel tarball seemed
slow and jerky. So I ran

	cd /tmp; time tar zxf /path/to/linux-2.5.8.tar.gz

on several boxes(*), comparing 2.4.19-pre7 with 2.5.8.

On the older boxes (2 PentiumIIs and one K6-III), 2.5.8 was slower
by factors of 2.3-4.5. A P4 with an IBM 60GXP "only" suffered a
40% slowdown.

/Mikael

(*) Standard Intel chipset PCs, IDE disks, ext2 file systems,
newly booted, idle, etc.