On Wed, 8 Feb 2017, Mel Gorman wrote: > It may be worth noting that patches in Andrew's tree no longer disable > interrupts in the per-cpu allocator and now per-cpu draining will > be from workqueue context. The reasoning was due to the overhead of > the page allocator with figures included. Interrupts will bypass the > per-cpu allocator and use the irq-safe zone->lock to allocate from > the core. It'll collide with the RT patch. Primary patch of interest is > http://www.ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-only-use-per-cpu-allocator-for-irq-safe-requests.patch Yeah, we'll sort that out once it hits Linus tree and we move RT forward. Though I have once complaint right away: + preempt_enable_no_resched(); This is a nono, even in mainline. You effectively disable a preemption point. > The draining from workqueue context may be a problem for RT but one > option would be to move the drain to only drain for high-order pages > after direct reclaim combined with only draining for order-0 if > __alloc_pages_may_oom is about to be called. Why would the draining from workqueue context be an issue on RT? Thanks, tglx -- 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>
