mm/sparse.c: use kvmalloc/kvfree to alloc/free memmap for the classic sparse

This change makes populate_section_memmap()/depopulate_section_memmap
much simpler.

Suggested-by: Michal Hocko <[email protected]>
Signed-off-by: Baoquan He <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Reviewed-by: David Hildenbrand <[email protected]>
Reviewed-by: Pankaj Gupta <[email protected]>
Reviewed-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Wei Yang <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Link: http://lkml.kernel.org/r/20200316125450.GG3486@MiWiFi-R3L-srv
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 3 insertions, 24 deletions

diff --git a/mm/sparse.c b/mm/sparse.c
index 55fe305e8d7b..f0705f4167cb 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -664,35 +664,14 @@ static void free_map_bootmem(struct page *memmap)
 struct page * __meminit populate_section_memmap(unsigned long pfn,
 		unsigned long nr_pages, int nid, struct vmem_altmap *altmap)
 {
-	struct page *page, *ret;
-	unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
-
-	page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
-	if (page)
-		goto got_map_page;
-
-	ret = vmalloc(memmap_size);
-	if (ret)
-		goto got_map_ptr;
-
-	return NULL;
-got_map_page:
-	ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
-got_map_ptr:
-
-	return ret;
+	return kvmalloc(array_size(sizeof(struct page),
+				   PAGES_PER_SECTION), GFP_KERNEL);
 }
 
 static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages,
 		struct vmem_altmap *altmap)
 {
-	struct page *memmap = pfn_to_page(pfn);
-
-	if (is_vmalloc_addr(memmap))
-		vfree(memmap);
-	else
-		free_pages((unsigned long)memmap,
-			   get_order(sizeof(struct page) * PAGES_PER_SECTION));
+	kvfree(pfn_to_page(pfn));
 }
 
 static void free_map_bootmem(struct page *memmap)