On Fri, Jun 24, 2016 at 04:59:55PM +0800, Hillf Danton wrote: > We stop reclaiming pages if any eligible zone is balanced. > > Signed-off-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> wakeup_kswapd avoids waking kswapd in the first place if there are balanced zones. The current code will do at least one reclaim pass if the situation changes between the wakeup request and kswapd actually waking so some progress will be made. The risk for strict enforcement is that small low zones like DMA will be quickly generally balanced but only for very short periods of time and kswapd will fall behind. It *shouldn't* matter as the pages allocated from DMA will remain resident until the full node LRU cycles through but it's a possibility. I'll test the patch and make sure kswapd still reclaims at the correct rate. Did you this test yourself with any reclaim intensive workload to see if kswapd fell behind forcing more stalls in direct reclaim? -- Mel Gorman SUSE Labs -- 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>