On Mon, Aug 30, 2021 at 10:10:51PM +0800, Miaohe Lin wrote: > Don't use with __GFP_HIGHMEM because page_address() cannot represent > highmem pages without kmap(). Newly allocated pages would leak as > page_address() will return NULL for highmem pages here. But It works > now because the only caller does not specify __GFP_HIGHMEM now. This is a misunderstanding of how alloc_pages_exact() / alloc_pages_exact_nid() work. You simply can't call them with GFP_HIGHMEM. If you really must change anything here, s/__GFP_COMP/(__GFP_COMP|__GFP_HIGHMEM)/g throughout both alloc_pages_exact() and alloc_pages_exact_nid().
