> The kernel has a timer that > updates this page atomically. which timer updates the page even when nobody is interested in knowing what the time is, increasing the noise in the system[1]. i still keep graphs of a full-blown plan9 cpu server with users logged in and close to 200 running processes exhibiting very little deviation:
http://mirtchovski.com/screenshots/ftq.jpg people are doing work negating the timer "optimization": http://ozlabs.org/~anton/linux/osjitter/ andrey [1] http://www.computer.org/portal/web/csdl/doi/10.1109/CLUSTR.2004.1392636
