Hmm... Wouldn't it make more sense for the fast path page allocator to allocate weighted-round-robin (by zone size) from each zone, rather than just starting from the highest and working down? This would mean that each zone would get a proportional amount of allocations and reclaiming a bit from each would likely throw out the oldest allocations, rather than some of that and and some more recent stuff that was allocated at the beginning of the lower zone. For example, with the current approach, a time progression of allocations looks like this (N=Normal, D=DMA32): 1N 2N 3N 4D 5D 6D 7D 8D 9D ...once the watermark is hit, kswapd reclaims 1 and 4, since they're oldest in each zone, but 2 and 3 were allocated earlier. Versus a weighted-round-robin approach: 1N 2D 3D 4N 5D 6D 7N 8D 9D ...kswapd reclaims 1 and 2, and they're oldest in time and maybe LRU. Things probably eventually mix up enough once the system has reclaimed and allocated more for a while with the current approach, but the allocations are still chunky depending on how many extra things kswapd reclaims to reach higher-order watermarks, and doesn't this always mess with the LRU when the there are multiple usable zones? Anyway, this approach might be horrible for some other reasons (page allocations hoping to be sequential? bigger cache footprint?), but it might reduce the requirements for other other workarounds, and it would make the LRU node-wide instead of zone-wide. Simon- -- 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>