[PATCH 10/10] mm/hugetlb: not necessary to abuse temporary page to workaround the nasty free_huge_page

Wei Yang
2020-08-07T09:13:41Z

Let's always increase surplus_huge_pages and so that free_huge_page
could decrease it at free time.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
---
mm/hugetlb.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1f2010c9dd8d..a0eb81e0e4c5 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1913,21 +1913,19 @@ static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
return NULL;

spin_lock(&hugetlb_lock);
+
+ h->surplus_huge_pages++;
+ h->surplus_huge_pages_node[page_to_nid(page)]++;
+
/*
* We could have raced with the pool size change.
* Double check that and simply deallocate the new page
- * if we would end up overcommiting the surpluses. Abuse
- * temporary page to workaround the nasty free_huge_page
- * codeflow
+ * if we would end up overcommiting the surpluses.
*/
- if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
- SetPageHugeTemporary(page);
+ if (h->surplus_huge_pages > h->nr_overcommit_huge_pages) {
spin_unlock(&hugetlb_lock);
put_page(page);
return NULL;
- } else {
- h->surplus_huge_pages++;
- h->surplus_huge_pages_node[page_to_nid(page)]++;
}

out_unlock:
--
2.20.1 (Apple Git-117)