On Thu, 21 Jun 2012, David Rientjes wrote: > It's possible that subsequent pageblocks would contain memory allocated > from solely non-oom memcgs, but it's certainly not a guarantee and results > in terrible performance as exhibited above. Is there another good > criteria to use when deciding when to stop isolating and attempting to > migrate all of these pageblocks? > > Other ideas? > The only other alternative that I can think of is to check mem_cgroup_margin() in isolate_migratepages_range() and return a NULL lruvec that would break that pageblock and return, and then set a bit in struct mem_cgroup that labels it as oom so we can check for it on subsequent pageblocks without incurring the locking to do mem_cgroup_margin() in res_counter, and then clear that bit on every uncharge to a memcg, but this still seems like a tremendous waste of cpu (especially if /sys/kernel/mm/transparent_hugepage/defrag == always) if most pageblocks contain pages from an oom memcg. -- 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>