On Mon, Mar 20, 2017 at 11:08:41AM -0700, hpa@xxxxxxxxx wrote: > This *better* be conditional on some kind of settable limit. Having a > barrier in the middle of the address space for no apparent reason to > "clean" software is insane. I had the same argument (on your side) before, but if you look on numbers it's far from the middle of address space. The barrier is around 0.2% from the start 56-bit address space. And it's we have vdso/vvar/stack just below the barier anyway. I don't think we would loose much if wouldn't not allow VMA to sit across it. -- Kirill A. Shutemov