Re: 2.6.14 kswapd eating too much CPU

[Nick Piggin]

Jan Kasprzak wrote:
> Andrew Morton wrote:
> : Jan Kasprzak <kas@xxxxxxxxxx> wrote:
> : >
> : > I have noticed that on my system kswapd eats too much CPU time every two
> : > hours or so. This started when I upgraded this server to 2.6.14.2 (was 2.6.13.2
> : > before), and added another 4 GB of memory (to the total of 8GB).
> : 
> : Next time it happens, please gather some memory info (while it's happening):
> : 
> : 	cat /proc/meminfo
[snip]

> 	Hope this helps,

Can't see anything yet. Sysrq-M would be good. cat /proc/zoneinfo gets you
most of the way there though.

A couple of samples would be handy, especially from /proc/vmstat.

cat /proc/vmstat > vmstat.out ; sleep 10 ; cat /proc/vmstat >> vmstat.out

The same for /proc/zoneinfo would be a good idea as well.

Also - when you say "too much cpu time", what does this mean? Does
performance noticably drop compared with 2.6.13 performing the same cron
job? Because kswapd is supposed to unburden other processes from page
reclaim work, so if it is working *properly*, then the more CPU it uses
the better.

Thanks,
Nick

--
SUSE Labs, Novell Inc.

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