On Wed, Nov 04, 2020 at 03:02:14PM -0400, Jason Gunthorpe wrote: > I saw that once and I really couldn't make sense of it.. > What use is having futex's that only work on THP pages? Confused > > CH said there was no case of HAVE_FAST_GUP !ARCH_HAS_PTE_SPECIAL, is > one hidden someplace then? ARCH_HAS_PTE_SPECIAL is selected by: arc arm (if LPAE) arm64 mips (if !(32BIT && CPU_HAS_RIXI)) powerpc riscv s390 sh sparc (if SPARC64) x86 HAVE_FAST_GUP is supported by: arm (if LPAE) arm64 mips powerpc s390 sh x86 so mips would be a candidate. But I think only in theory, as the options selecting CPU_HAS_RIXI do not select CPU_SUPPORTS_HUGEPAGES. Adding the mips maintainer to double check my logic.
