On Thu, May 12, 2011 at 11:48:19AM -0500, Christoph Lameter wrote: > Try order = 1 which gives you SLAB like interaction with the page > allocator. Then we at least know that it is the order 2 and 3 allocs that > are the problem and not something else. order 1 should work better, because it's less likely we end up here (which leaves RECLAIM_MODE_LUMPYRECLAIM on and then see what happens at the top of page_check_references()) else if (sc->order && priority < DEF_PRIORITY - 2) sc->reclaim_mode |= syncmode; with order 1 more likely we end up here as enough pages are freed for order 1 and we're safe: else sc->reclaim_mode = RECLAIM_MODE_SINGLE | RECLAIM_MODE_ASYNC; None of these issue should materialize with COMPACTION=n. Even __GFP_WAIT can be left enabled to run compaction without expecting adverse behavior, but running compaction may still not be worth it for small systems where the benefit of having order 1/2/3 allocation may not outweight the cost of compaction itself. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>