On Wed, Jul 13, 2005 at 10:24:10AM -0700, David Lang wrote: > >How serious is the 1/HZ = sane problem, and more to the point how many > >programs get the HZ value with a system call as opposed to including a > >header or building it in? I know some of my older programs use header > >files, that was part of the planning for the future even before 2.5 > >started. At the time I didn't expect to have to use the system call. > > in binary 1/100 or 1/1000 are not sane values to start with so I don't > think that that this is likly to be that critical (remembering that the > kernel doesn't do floating point math) No, but 1/1000Hz = 1000000ns, while 1/864Hz = 1157407.407ns. If you have a counter that counts the ticks in nanoseconds (xtime ...), the first will be exact, the second will be accumulating an error.
It's a tradeoff. -- Vojtech Pavlik SuSE Labs, SuSE CR - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/