Hello all, I apologize if this might be more appropriate for a Linux list. From our time-series graphs, we are noticing that the percentage of CPU cycles spent on 'system' tasks grows considerably under heavy load. Does anyone know what kinds of operations fall under 'system'? Task switching, paging, these kinds of things? When load is light, it appears that the same 1 or 2 Zope threads will handle the requests. As load increases, then more threads get into the mix. How likely is it that this increase in 'system' CPU cycles is stemming from having to switch between the Zope threads? Perhaps Zope goes into a near dead-lock state and starts to spend a bunch of time waiting for other threads to release a lock? The reason I mention this is that we don't notice the increased amount of 'system' CPU when the load increases on other servers (Apache, MySQL) on other machines. System info: Zope 2.1.6, Redhat 6.2, PC arch Thanks, Erik