Encapsulate kmalloc vs vmalloc memory allocation and freeing logic into
two helpers, ceph_kvmalloc() and ceph_kvfree(), and switch to them.
ceph_kvmalloc() kmalloc()'s a maximum of 8 pages, anything bigger is
vmalloc()'ed with __GFP_HIGHMEM set. This changes the existing
behaviour:
- for buffers (ceph_buffer_new()), from trying to kmalloc() everything
and using vmalloc() just as a fallback
- for messages (ceph_msg_new()), from going to vmalloc() for anything
bigger than a page
- for messages (ceph_msg_new()), from disallowing vmalloc() to use high
memory
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
eeb0bed557