> On Apr 8, 2022, at 10:28 PM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > 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. Will add it in v2. Thanks, Song
