On Wed, Nov 07, 2007 at 12:30:45PM -0800, Andrew Morton wrote: > Ow. Yes, from my reading delay_tsc() can return early (or after > heat-death-of-the-universe) if the TSCs are offset and if preemption > migrates the calling task between CPUs. > > I suppose a lameo fix would be to disable preemption in delay_tsc().
preempt_disable is lousy documentation here. This and other cases (lots of per_cpu users, IIRC) actually want a migrate_disable() which is a proper subset. We can simply implement migrate_disable() as preempt_disable() for now and come back later and implement a proper migrate_disable() that still allows preemption (and thus avoids the latency). -- Mathematics is the supreme nostalgia of our time. - 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/
