RE: kswapd causing giant load

["Wendy Cheng" <s_wendy_cheng@xxxxxxxxxxx>]

Would you be able to recreate this problem  away from 3ware controller 
and/or non-RAID-5 setting ? Check out: 
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=121434, comment #263 - 
more specifically (cut and paste the relevant info):

"Different kernels might tweak different parameters that will affect RAID-5
operations on 3Ware Escalade 7000/8000 series controllers.
Finding a good set (3Ware's site has excellent recommendations) and putting
those in your /etc/rc.d/rc.local or similar is _crucial_ for a production 
server
to minimize any change in defaults with any new kernel."

-- Wendy

----Original Message Follows----
From: Gaspar Bakos <gbakos@xxxxxxxxxxxxxxx>
Reply-To: gbakos@xxxxxxxxxxxxxxx
To: linux-xfs@xxxxxxxxxxx
Subject: kswapd causing giant load
Date: Sat, 4 Jun 2005 12:35:48 -0400 (EDT)

Hi,

I encounter a giant load (up to 10.0) when I copy files, either from a
remote server to the local machine, or even locally. Because I use XFS
filesystem, I decided to forward my email to the XFS list; maybe
anyone has a clue.

The setup is:
OS: Redhat FC3 with 2.6.11-1.14_FC3smp (redhat distro) kernel, XFS 
filesystem
HW: Dual opteron 2.0GHz on Tyan motherboard, 4Gb RAM

The partition i am using is:
2.1Tb hardware RAID-5 unit served by 3ware controller (8 x 300Gb)
OR
300Gb simple SATA disk, also served by a 3ware controller.

I have no clue where to start combatting this problem.
- Kernel specific?
- Due to improper setup of the 3ware controllers?
- XFS filesystem specific?

10715 hatuser   15   0 35432 2792 2020 R 28.3  0.1   1:45.06 sshd
10724 hatuser   16   0 17504  11m  664 R  8.3  0.3   0:33.56 rsync
  175 root      15   0     0    0    0 S 19.7  0.0 136:25.58 kswapd0
  172 root      15   0     0    0    0 S  0.3  0.0   1:23.59 pdflush
  174 root      15   0     0    0    0 S  0.3  0.0  99:18.93 kswapd1

Before I start extensive experimenting, maybe someone knows right away
what causes high loads due to "kswapd* and pdflush".

Cheers
Gaspar