On Fri, Jul 15, 2005 at 07:57:01PM +0200, Andi Kleen wrote: > > I wouldn't say it is totally impossible. There are ways in which Linux can > > work > > without a reliable Local APIC timer. One option being - make one CPU that > > gets > > the external timer interrupt multicast an IPI to all the other CPUs that > > wants to get periodic timer interrupt. > > That doesn't mix very well with variable ticks. And I believe > we really need them.
It should work with variable ticks as we can easily add/remove CPUs from this multicast destination. > For no tick in idle you need a timer for each CPU that > can be programmed to a reasonably long interval to wake you > up after longer idleness. And all that > should work without bouncing cache lines around all the time > because that doesn't work on larger systems. And each CPU timer itself does very little writes in terms of caches. The two things that happen here are scheduler_tick and kstat_accounting. Or am I missing something? Did you have anything specific in mind wrt bouncing cachelines? Thanks, Venki - 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/
