[149/181] mm/hugetlb: narrow the hugetlb_lock protection area during preparing huge page

Commit Message

Andrew Morton Oct. 13, 2020, 11:56 p.m. UTC

From: Wei Yang <[e-mail]>
Subject: mm/hugetlb: narrow the hugetlb_lock protection area during preparing huge page

set_hugetlb_cgroup_[rsvd] just manipulate page local data, which is not
necessary to be protected by hugetlb_lock.

Let's take this out.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Wei Yang <[e-mail]>
Reviewed-by: Baoquan He <[e-mail]>
Reviewed-by: Mike Kravetz <[e-mail]>
Cc: Vlastimil Babka <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/hugetlb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

--- a/mm/hugetlb.c~mm-hugetlb-narrow-the-hugetlb_lock-protection-area-during-preparing-huge-page
+++ a/mm/hugetlb.c
@@ -1504,9 +1504,9 @@  static void prep_new_huge_page(struct hs
 {
 	INIT_LIST_HEAD(&page->lru);
 	set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
-	spin_lock(&hugetlb_lock);
 	set_hugetlb_cgroup(page, NULL);
 	set_hugetlb_cgroup_rsvd(page, NULL);
+	spin_lock(&hugetlb_lock);
 	h->nr_huge_pages++;
 	h->nr_huge_pages_node[nid]++;
 	spin_unlock(&hugetlb_lock);