On Tue, Jun 08, 2021 at 08:06:17PM +0200, Claudio Imbrenda wrote:

The recent patches to add support for hugepage vmalloc mappings added a
flag for __vmalloc_node_range to allow to request small pages.
This flag is not accessible when calling vmalloc, the only option is to
call directly __vmalloc_node_range, which is not exported.

This means that a module can't vmalloc memory with small pages.

Case in point: KVM on s390x needs to vmalloc a large area, and it needs
to be mapped with small pages, because of a hardware limitation.

This patch exports __vmalloc_node_range so it can be used in modules
too.

No.  I spent a lot of effort to mak sure such a low-level API is
not exported.