Hi Zlatko, On Mon, Jul 22, 2013 at 06:48:52PM +0200, Zlatko Calusic wrote: > On 19.07.2013 22:55, Johannes Weiner wrote: > >The way the page allocator interacts with kswapd creates aging > >imbalances, where the amount of time a userspace page gets in memory > >under reclaim pressure is dependent on which zone, which node the > >allocator took the page frame from. > > > >#1 fixes missed kswapd wakeups on NUMA systems, which lead to some > > nodes falling behind for a full reclaim cycle relative to the other > > nodes in the system > > > >#3 fixes an interaction where kswapd and a continuous stream of page > > allocations keep the preferred zone of a task between the high and > > low watermark (allocations succeed + kswapd does not go to sleep) > > indefinitely, completely underutilizing the lower zones and > > thrashing on the preferred zone > > > >These patches are the aging fairness part of the thrash-detection > >based file LRU balancing. Andrea recommended to submit them > >separately as they are bugfixes in their own right. > > > > I have the patch applied and under testing. So far, so good. It > looks like it could finally fix the bug that I was chasing few > months ago (nicely described in your bullet #3). But, few more days > of testing will be needed before I can reach a quality verdict. I should have remembered that you talked about this problem... Thanks a lot for testing! May I ask for the zone layout of your test machine(s)? I.e. how many nodes if NUMA, how big Normal and DMA32 (on Node 0) are. -- 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>