On Sun, 2011-05-29 at 13:46 +0530, Ankita Garg wrote: > > It's worth noting that we already do targeted reclaim on boundaries > > other than zones. The lumpy reclaim and memory compaction logically do > > the same thing. So, it's at least possible to do this without having > > the global LRU designed around the way you want to reclaim. > > > My understanding maybe incorrect, but doesn't both lumpy reclaim and > memory compaction still work under zone boundary ? While trying to free > up higher order pages, lumpy reclaim checks to ensure that pages that > are selected do not cross zone boundary. Further, compaction walks > through the pages in a zone and tries to re-arrange them. I'm asserting that we don't need memory regions in the pgdat->regions[]->zones[] layout to do what you're asking for. Lumpy reclaim is limited to a zone because it's trying to satisfy and allocation request that came in for *THAT* *ZONE*. It's useless to go clear out other zones. In your case, you don't care about zone boundaries: you want to reclaim things regardless. There was a "cma: Contiguous Memory Allocator added" patch posted a bit ago to linux-mm@. You might want to take a look at it for some inspiration. I think you also need to clearly establish here why any memory that you're going to want to power off can't use (or shouldn't use) ZONE_MOVABLE. It seems a bit silly to have it there, and ignore it for such a similar use case. Memory hot-remove and power-down are not horrifically different beasts. BTW, that's probably something else to add to your list: make sure mem_map[]s for memory in a region get allocated *in* that region. -- Dave -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>