> Persistent memory does have unpoisoning and would require this inverse > operation - see drivers/nvdimm/pmem.c pmem_clear_poison() and core.c > nvdimm_clear_poison(). Nice. Well this code will need to cooperate with that ... in particular if the page is in an area that can be unpoisoned ... then we should do that *instead* of marking the page not present (which breaks up huge/large pages and so affects performance). Instead of calling it "arch_unmap_pfn" it could be called something like arch_handle_poison() and do something like: void arch_handle_poison(unsigned long pfn) { if this is a pmem page && pmem_clear_poison(pfn) return if this is a nvdimm page && nvdimm_clear_poison(pfn) return /* can't clear, map out from 1:1 region */ ... code from my patch ... } I'm just not sure how those first two "if" bits work ... particularly in terms of CONFIG dependencies and system capabilities. Perhaps each of pmem and nvdimm could register their unpoison functions and this code could just call each in turn? -Tony -- 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