> The only reason the x86 ticket locks have the 256 CPu limit is that > if they go any bigger, we can't use the partial registers so would > have to have a few more instructions.
x86_64 is going up to 4k or 16k cpus soon for our new hardware. > A 32 bit spinlock would allow 64K cpus (ticket lock has 2 counters, > each would be 16 bits). And it would actually shrink the spinlock in > the case of preempt kernels too (because it would no longer have the > lockbreak field). > > And yes, I'll go out on a limb and say that 64k CPUs ought to be > enough for anyone ;) I think those things need a timeframe applied to it. Thats likely going to be true for the next 3 years (optimistic assessment ;-)). Could you go to 32bit spinlock by default? How about NUMA awareness for the spinlocks? Larger backoff periods for off node lock contentions please. -- 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/
