Linus Torvalds <[EMAIL PROTECTED]> writes: > And in short-term things, the timeval/jiffie conversion is likely to be a > _bigger_ issue than the crystal frequency conversion. > > So we should aim for a HZ value that makes it easy to convert to and from > the standard user-space interface formats. 100Hz, 250Hz and 1000Hz are all > good values for that reason. 864 is not.
Probably only theoretical, and probably the hardware isn't up to it... But what if we have: - 64-bit jiffies done in hardware (a counter). 1 cycle = 1 microsecond or even a CPU clock cycle. Can *APIC or another HPET do that? - 64-bit "match timer" (i.e., a register in the counter which fires IRQ when it matches the counter value) - the CPU(s) sorting the timer list and programming "match timer" with software timer next to be executed. Upon firing the timer, a new "next to be executed" timer would be programmed into the counter's "match timer". We would have no timer ticks when nobody requested them - the CPUs would be allowed to sleep for, say, even 50 ms when no task is RUNNING. -- Krzysztof Halasa - 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/
