Re: 2.6.1 slower than 2.4, smp/scsi/sw-raid/reiserfs

Andrew Morton
2004-02-01T23:10:11Z

Philip Martin <philip@codematters.co.uk> wrote:
>
> The machine is a dual P3 450MHz, 512MB, aic7xxx, 2 disk RAID-0 and
> ReiserFS. It's a few years old and has always run Linux, most
> recently 2.4.24. I decided to try 2.6.1 and the performance is
> disappointing.

2.6 has a few performance problems under heavy pageout at present. Nick
Piggin has some patches which largely fix it up.

> My test is a software build of about 200 source files (written in C)
> that I usually build using "nice make -j4".

Tried -j3?

> Timing the build on
> 2.4.24 I typically get something like
>
> 242.27user 81.06system 2:44.18elapsed 196%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (1742270major+1942279minor)pagefaults 0swaps
>
> and on 2.6.1 I get
>
> 244.08user 116.33system 3:27.40elapsed 173%CPU (0avgtext+0avgdata 0maxresident)k
> 0inputs+0outputs (0major+3763670minor)pagefaults 0swaps

hm, the major fault accounting is wrong.