--On March 22, 2007 9:25:27 AM +0100 Eric Thomas <[log in to unmask]> wrote: > Ah yes, and I recompile all my Linux guests to set HZ to something > sensible, like 100. A typical 2-way Linux guest request 3,000 timer > interrupts per second to try and keep the time accurate, and these are > expensive virtual interrupts. If you have 5 Linux guests, that's 15,000 > timer interrupts per second and you can start ordering a processor > upgrade just to count microseconds on an industrial scale. This ought to > be a kernel startup option so that you can change it without recompiling. HZ is used as a macro allover in the kernel, not a variable. It's used in a lot of places that need to be static, not computed, values, as well. Unlikely to see this happen. Used to be 100 was the default on x86 machines. I noticed 2.6 seems to have pushed that to 250 or so. > > Eric > -- "Genius might be described as a supreme capacity for getting its possessors into trouble of all kinds." -- Samuel Butler