On Fri, Apr 24, 2015 at 03:04:27PM -0400, Waiman Long wrote: > >>Within a NUMA node, however, we can split the > >>memory initialization to 2 or more local CPUs if the memory size is > >>big enough. > >> > >I considered it but discarded the idea. It'd be more complex to setup and > >the two CPUs could simply end up contending on the same memory bus as > >well as contending on zone->lock. > > > > I don't think we need that now. However, we may have to consider > this when one day even a single node can have TBs of memory unless > we move to a page size larger than 4k. > We'll cross that bridge when we come to it. I suspect there is more room for improvement in the initialisation that would be worth trying before resorting to more threads. With more threads there is a risk that we hit memory bus contention and a high risk that it actually is worse due to contending on zone->lock when freeing the pages. In the meantime, do you mind updating the before/after figures for your test machine with this series please? -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>