On Tue, Nov 23, 2010 at 10:43:29PM -0800, Simon Kirby wrote: > On Tue, Nov 23, 2010 at 10:04:03AM +0000, Mel Gorman wrote: > > > On Mon, Nov 22, 2010 at 03:44:19PM -0800, Andrew Morton wrote: > > > On Mon, 15 Nov 2010 11:52:46 -0800 > > > Simon Kirby <sim@xxxxxxxxxx> wrote: > > > > > > > I noticed that CONFIG_NUMA seems to enable some more complicated > > > > reclaiming bits and figured it might help since most stock kernels seem > > > > to ship with it now. This seems to have helped, but it may just be > > > > wishful thinking. We still see this happening, though maybe to a lesser > > > > degree. (The following observations are with CONFIG_NUMA enabled.) > > > > > > > > Hi, > > > > As this is a NUMA machine, what is the value of > > /proc/sys/vm/zone_reclaim_mode ? When enabled, this reclaims memory > > local to the node in preference to using remote nodes. For certain > > workloads this performs better but for users that expect all of memory > > to be used, it has surprising results. > > > > If set to 1, try testing with it set to 0 and see if it makes a > > difference. Thanks > > Hi Mel, > > It is set to 0. It's an Intel EM64T...I only enabled CONFIG_NUMA since > it seemed to enable some more complicated handling, and I figured it > might help, but it didn't seem to. It's also required for > CONFIG_COMPACTION, but that is still marked experimental. > I'm surprised a little that you are bringing compaction up because unless there are high-order involved, it wouldn't make a difference. Is there a constant source of high-order allocations in the system e.g. a network card configured to use jumbo frames? A possible consequence of that is that reclaim is kicking in early to free order-[2-4] pages that would prevent 100% of memory being used. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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 policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>