> What's the benefit of doing so - and why has not it been done before? > I mean, I run a regular 2.6.18.6, > /sys/devices/system/clocksource/clocksource0/current_clocksource (is this > related?) shows "acpi_pm", but the IRQ0 counter increases at HZ. Maybe I > am confusing things, but why the need for PIT when clocksource is acpi_pm > anyway?
you're mixing up 2 concepts: 1) clocksource 2) eventsource 1) is for "what time is it now", and acpi_pm is useful for that, as are several other things such as rdtsc 2) is for "I need THIS to happen X miliseconds from now". acpi_pm is not useful for that, nor is rdtsc. some can be used for both (PIT), but on a concept level the uses are independent. The advantage of local apic over PIT is that local apic is cheap to do "one shot" future events with, while the PIT will tick periodic at a fixed frequency. With tickless idle.. that's not what you want. -- if you want to mail me at work (you don't), use arjan (at) linux.intel.com Test the interaction between Linux and your BIOS via http://www.linuxfirmwarekit.org - 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/