On Tue, Apr 10, 2007 at 08:24:22AM +0200, Ingo Molnar wrote: > > * Siddha, Suresh B <[EMAIL PROTECTED]> wrote: > > > Align the per cpu runqueue to the cacheline boundary. This will > > minimize the number of cachelines touched during remote wakeup. > > > -static DEFINE_PER_CPU(struct rq, runqueues); > > +static DEFINE_PER_CPU(struct rq, runqueues) ____cacheline_aligned_in_smp; > > ouch!! Now how did _that_ slip through. The runqueues had been > cacheline-aligned for ages. Or at least, they were supposed to be.
perhaps the per_cpu definition gave the impression of cacheline aligned too.. > > could you see any improvement in profiles or workloads with this patch > applied? (just curious - it's an obviously right fix) We have seen 0.5% perf improvement on database workload on a 2 node setup. 0.5% is a very good improvement for this workload. thanks, suresh - 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/