On Thu, 9 Aug 2012, Hanjun Guo wrote: > Now, We have node masks for both N_NORMAL_MEMORY and > N_HIGH_MEMORY to distinguish between normal and highmem on platforms such as > x86. > But we still don't have such a mechanism to distinguish between "normal" and > "movable" > memory.
What is the exact difference that you want to establish? > As suggested by Christoph Lameter in threads > http://marc.info/?l=linux-mm&m=134323057602484&w=2, we introduce N_LRU_MEMORY > to > distinguish between "normal" and "movable" memory. Well seems that I am having second thoughts about this. While is it true that current page migration can only move pages on the LRU there are already various mechanisms proposed and implemented that can move pages not on the LRU (like page table pages). Not sure if this is still a useful distinction to make. There is also the issue that segments from "N_LRU_MEMORY" may be allocated and then become not movable anymore. For the slab case that you want to solve here you will need to know if the node has *only* movable memory and will never have any ZONE_NORMAL memory. If so then memory control structures for allocators that do not allow movable memory will not need to be allocated for these node. The node can be excluded from handling. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/