On Wed, Jun 09, 2021 at 06:28:09PM +0200, Claudio Imbrenda wrote: > On Wed, 9 Jun 2021 16:59:17 +0100 > Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > > 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. > > ok, but then how can we vmalloc memory with small pages from KVM? Does the s390x support CONFIG_HAVE_ARCH_HUGE_VMALLOC what is arch specific? If not then small pages are used. Or am i missing something? I agree with Christoph that exporting a low level internals is not a good idea. -- Vlad Rezki
