On 5/24/19 6:20 PM, David Miller wrote: >> On the other hand, arm64 currently allows the virtual address size >> to be configurable, currently defaulting to 48 bits [2, 3]. I was >> therefore wondering whether we could make MAX_PHYS_ADDRESS_BITS [4] >> configurable as well to be able to support these JITs on >> Debian/sparc64 for the foreseeable future by limiting the virtual >> address space to 47 or 48 bits. > > You can't just do this. > > It is possible that all physical memory is mapped to the top of the > mappable physical address range, therefore we really need to use the > full maximum setting supported by the CPU. Yes, my initial mail was incorrect. What I actually meant was reducing the size of the va_hole in userspace so that the top-most address that mmap() would return is not beyond 2^47. Would it be possible to add such a workaround until the JITs have fixed their broken code? Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer - glaubitz@xxxxxxxxxx `. `' Freie Universitaet Berlin - glaubitz@xxxxxxxxxxxxxxxxxxx `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
