On 12/02/2015 02:03 PM, Dan Williams wrote: >>> >> Is pfn_valid() a reliable check? It seems to be based on a max_pfn >>> >> per node... what happens when pmem is located below that point. I >>> >> haven't been able to convince myself that we won't get false >>> >> positives, but maybe I'm missing something. >> > >> > With sparsemem at least, it makes sure that you're looking at a valid >> > _section_. See the pfn_valid() at ~include/linux/mmzone.h:1222. > At a minimum we would need to add "depends on SPARSEMEM" to "config FS_DAX_PMD". Yeah, it seems like an awful layering violation. But, sparsemem is turned on everywhere (all the distros/users) that we care about, as far as I know. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html