order >= MAX_ORDER pages can't be freed to buddy system directly, this patch
destroy the gigantic hugetlb page to normal order-0 pages and free them one
by one.
Signed-off-by: Wanpeng Li <liw...@linux.vnet.ibm.com>
---
mm/hugetlb.c | 39 +++++++++++++++++++++++++++++----------
mm/internal.h | 1 +
mm/page_alloc.c | 2 +-
3 files changed, 31 insertions(+), 11 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4a0c270..eeaf6f2 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -579,25 +579,44 @@ err:
return NULL;
}
+static inline clear_page_flag(struct page *page)
+{
+ page->flags &= ~(1 << PG_locked | 1 << PG_error |
+ 1 << PG_referenced | 1 << PG_dirty |
+ 1 << PG_active | 1 << PG_reserved |
+ 1 << PG_private | 1 << PG_writeback);
+}
+
static void update_and_free_page(struct hstate *h, struct page *page)
{
int i;
+ struct page *p;
+ int order = huge_page_order(h);
- VM_BUG_ON(h->order >= MAX_ORDER);
+ VM_BUG_ON(!hugetlb_shrink_gigantic_pool && h->order >= MAX_ORDER);
h->nr_huge_pages--;
h->nr_huge_pages_node[page_to_nid(page)]--;
- for (i = 0; i < pages_per_huge_page(h); i++) {
- page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
- 1 << PG_referenced | 1 << PG_dirty |
- 1 << PG_active | 1 << PG_reserved |
- 1 << PG_private | 1 << PG_writeback);
- }
- VM_BUG_ON(hugetlb_cgroup_from_page(page));
set_compound_page_dtor(page, NULL);
- set_page_refcounted(page);
arch_release_hugepage(page);
- __free_pages(page, huge_page_order(h));
+ VM_BUG_ON(hugetlb_cgroup_from_page(page));
+
+ if (order < MAX_ORDER) {
+ for (i = 0; i < pages_per_huge_page(h); i++)
+ clear_page_flag(page+i);
+ set_page_refcounted(page);
+ __free_pages(page, huge_page_order(h));
+ } else {
+ int nr_pages = 1 << order;
+ destroy_compound_page(page, order);
+ set_compound_order(page, 0);
+ for (i = 0, p = page; i < nr_pages; i++,
+ p = mem_map_next(p, page, i)) {
+ clear_page_flag(p);
+ set_page_refcounted(p);
+ __free_pages(p, 0);
+ }
+ }
}
struct hstate *size_to_hstate(unsigned long size)
diff --git a/mm/internal.h b/mm/internal.h
index 8562de0..a63a35f 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -101,6 +101,7 @@ extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned
long address);
*/
extern void __free_pages_bootmem(struct page *page, unsigned int order);
extern void prep_compound_page(struct page *page, unsigned long order);
+extern int destroy_compound_page(struct page *page, unsigned long order);
#ifdef CONFIG_MEMORY_FAILURE
extern bool is_free_buddy_page(struct page *page);
#endif
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1394c5a..0ea14ba 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -367,7 +367,7 @@ void prep_compound_page(struct page *page, unsigned long
order)
}
/* update __split_huge_page_refcount if you change this function */
-static int destroy_compound_page(struct page *page, unsigned long order)
+int destroy_compound_page(struct page *page, unsigned long order)
{
int i;
int nr_pages = 1 << order;
--
1.7.10.4
--
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