I have three virtual linux servers running on Slicehost.
Two of them are running 2.6.24-23-xen one is running 2.6.18-xen. All three servers are running almost identical software but the behaviour of top is different between the 2.6.24 and 2.6.18 servers.
On the one running 2.6.18, the set of processes running (ordered by CPU activity) is pretty constant when no users are connected. The other two show constant changes in activity. In particular Ruby based services (mongrel_rails, merb and event-machine) are constantly jumping up and back down the list.
All servers are running ruby 1.8.7 (2008-08-11 patchlevel 72).
Any ideas why there is such a difference in behaviour?