On Wednesday 08 March 2006 11:18, David Mansfield wrote: > The system is slow, relatively (866Mhz cpu) and the network is fast > (gigabit) so the limiting factor should be CPU. What is the actual throughput on the GigE? What KIND of GigE? Which driver? > However, at times, the system gets into a 'weird' state where instead of > using about 85% user/ 15% system, it goes to 50% user and 50% system. > Now 50% system time for this load is ridiculous, and as I said before, > most of the time it is 85/15 and only occasionally get's 'stuck' in > 50/50. > CPU: CPU with timer interrupt, speed 0 MHz (estimated) > Profiling through timer interrupt > samples % symbol name > 21117 36.5340 default_idle > This is CRAZY! How can default_idle be sucking away cycles when the > system is (should be) cpubound? > Can anyone explain this? GigE DMA, perhaps? DMA time would show as cpu idle, I would think. Bus contention between the GigE and the disk? (Servers have split buses for a reason...and PCIe is a switched architecture for a reason) -- Lamar Owen Director of Information Technology Pisgah Astronomical Research Institute 1 PARI Drive Rosman, NC 28772 (828)862-5554 www.pari.edu