Hi, In trying to debug an issue, I came across this text in the config COMPACTION menu item: > Compaction is the only memory management component to form > high order (larger physically contiguous) memory blocks > reliably. The page allocator relies on compaction heavily and > the lack of the feature can lead to unexpected OOM killer > invocations for high order memory requests. You shouldn't > disable this option unless there really is a strong reason for > it and then we would be really interested to hear about that at > linux-mm@xxxxxxxxx. So, here I am as requested. My system has 64 gigs of ram. Often times when starting up VMs, with either QEMU/KVM or with VMware, the VM will be extremely sluggish and laggy for a little while, usually around 5 minutes. During that phase, I see kcompact0 using 100% CPU. But other times this doesn't happen at all. I figured I'd try removing CONFIG_COMPACTION and seeing what happens, but then I saw your admonishment, so here I am. Has anybody else seen this behavior? Jason