On Fri, Apr 08, 2022 at 03:34:42PM -0700, Song Liu wrote: > Huge page backed vmalloc memory could benefit performance in many cases. > Since some users of vmalloc may not be ready to handle huge pages, > VM_NO_HUGE_VMAP was introduced to allow vmalloc users to opt-out huge > pages. However, it is not easy to add VM_NO_HUGE_VMAP to all the users > that may try to allocate >= PMD_SIZE pages, but are not ready to handle > huge pages properly. > > Replace VM_NO_HUGE_VMAP with an opt-in flag, VM_ALLOW_HUGE_VMAP, so that > users that benefit from huge pages could ask specificially. Given that the huge page backing was added explicitly for some big boot time allocated hashed,those should probably have the VM_ALLOW_HUGE_VMAP added from the start (maybe not in this patch, but certainly in this series). We'll probably also need a vmalloc_huge interface for those.
