On Mon, Apr 24, 2017 at 10:37:40PM +0200, John Paul Adrian Glaubitz wrote: > On 04/24/2017 06:19 PM, Kirill A. Shutemov wrote: > > In proposed implementation, we also use hint address, but in different > > way: by default, if hint address is NULL, kernel would not create mappings > > above 47-bits, preserving compatibility. > > Ooooh, that would solve a lot of problems actually if it were to be available > on all architectures. On SPARC, the situation is really annoying and I have > been discussing a solution with the Qt developers and they suggested a > similar approach, just one that would also apply to brk() [1]. > > > If an application wants to have access to larger address space, it has to > > specify hint addess above 47-bits. > > > > See details here: > > > > http://lkml.kernel.org/r/20170420162147.86517-10-kirill.shutemov@xxxxxxxxxxxxxxx > > Thanks. I'll have a read. Although from your message I'm reading out that > this particular proposal got rejected. No. I just wasn't applied yet, so situation may change. > Would be really nice to able to have a canonical solution for this issue, > it's been biting us on SPARC for quite a while now due to the fact that > virtual address space has been 52 bits on SPARC for a while now. Power folks are going to implement similar approach. I don't see why Sparc can't go the same route. -- Kirill A. Shutemov
