> > To avoid excessive reclaim, we give up rebalancing for high order > > allocations right after reclaiming enough pages. > > hm. What are the observed runtime effects of this change? Any testing > results? > This work was based on Mel's work, Sir, "[PATCH 00/27] Move LRU page reclaim from zones to nodes v7".
In "[PATCH 06/27] mm, vmscan: Make kswapd reclaim in terms of nodes", fragmentation detection is introduced to avoid excessive reclaim. We bail out of balancing for high-order allocations if the pages reclaimed at the __current__ reclaim priority are two times more than required. In this work we give up reclaiming for high-order allocations if the __total__ number of pages reclaimed, from the first priority to the current priority, is more than needed, and in net result we reclaim less pages. Given " [PATCH 00/34] Move LRU page reclaim from zones to nodes v9" is delivered, I will send this work if necessary, after Mel's work landing in the -mm tree. thanks Hillf
