For the record the futex test case OOPSes a 5.3-rc3 kernel running on a Sun Blade 2500 (2 x USIIIi). This system runs a custom distro with a custom toolchain (gcc-8.3 based), so I doubt it's a distro problem. On Sat, Aug 10, 2019 at 9:17 AM Christoph Hellwig <hch@xxxxxx> wrote: > > There isn't really a way to use an arch-specific get_user_pages_fast > in mainline, you'd need to revert the whole series. As a relatively > quick workaround you can just remove the > > select HAVE_FAST_GUP if SPARC64 > > line from arch/sparc/Kconfig
