On 25.08.2017 18:16, Kirill A. Shutemov wrote: > On Fri, Aug 25, 2017 at 09:02:36AM -0700, Christoph Hellwig wrote: >> On Fri, Aug 25, 2017 at 06:58:03PM +0300, Kirill A. Shutemov wrote: >>> Not all archs are ready for this: >>> >>> arch/parisc/include/uapi/asm/mman.h:#define MAP_TYPE 0x03 /* Mask for type of mapping */ >>> arch/parisc/include/uapi/asm/mman.h:#define MAP_FIXED 0x04 /* Interpret addr exactly */ >> >> I'd be happy to say that we should not care about parisc for >> persistent memory. We'll just have to find a way to exclude >> parisc without making life too ugly. > > I don't think creapling mmap() interface for one arch is the right way to > go. I think the interface should be universal. > > I may imagine MAP_DIRECT can be useful not only for persistent memory. > For tmpfs instead of mlock()? On parisc we have #define MAP_SHARED 0x01 /* Share changes */ #define MAP_PRIVATE 0x02 /* Changes are private */ #define MAP_TYPE 0x03 /* Mask for type of mapping */ #define MAP_FIXED 0x04 /* Interpret addr exactly */ #define MAP_ANONYMOUS 0x10 /* don't use a file */ So, if you need a MAP_DIRECT, wouldn't e.g. #define MAP_DIRECT 0x08 be possible (for parisc, and others 0x04). And if MAP_TYPE needs to include this flag on parisc: #define MAP_TYPE (0x03 | 0x08) /* Mask for type of mapping */ Helge
