topic Re: RHEL3 Update 3. Kswapd eat more CPU in Operating System - Linux

RHEL3 Update 3. Kswapd eat more CPU

JBR — Thu, 11 Aug 2005 04:42:56 GMT

Hi, does anybody know why kswapd process eat a lot of CPU?

[root@root]# ps -ef | grep kswapd
root 11 1 18 Aug10 ? 04:31:23[kswapd]

[root@baladi root]# free
total used free shared buffers cached
Mem: 7973808 7943296 30512 0 313248 6200948
-/+ buffers/cache: 1429100 6544708
Swap: 2097136 0 2097136

Kernel is 2.4.21-19ELsmp

What ways I can explore to troubleshot this cause?

Thanks and best regards...

Re: RHEL3 Update 3. Kswapd eat more CPU

Steven E. Protter — Thu, 11 Aug 2005 05:27:38 GMT

Swap processes eat up a lot of CPU when a system is overworked.

What I mean by overworked is there is to much demand for memory by processes and your system is constantly swapping processes from memory to disk and back again.

There are two solutions, the first of which I favor:

1) Get more memory and install it.
2) Decrease the workload on the system, as in run less stuff.

You could also tune your applications and try and cut their memory demand. Oracle SGA tends to be a bit greedy for example.

SEP

Re: RHEL3 Update 3. Kswapd eat more CPU

JBR — Thu, 11 Aug 2005 05:44:42 GMT

Hi Steven thanks a lot for your quickly reply, but the swap utilization is 0%? Why the processes not are swapped out?

Thanks..

Re: RHEL3 Update 3. Kswapd eat more CPU

Vitaly Karasik_1 — Thu, 11 Aug 2005 07:59:45 GMT

there were *many* bugs in RHEL's kswapd (http://www.google.com/search?hl=en&q=kswapd+rhel+bug).
I suggest you to upgrade to current RHEL3 upd 5

Rgds,
Vitaly