From: Wei Yang <richard.weiyang@linux.alibaba.com>
Date: Tue, 13 Oct 2020 23:56:36 +0000 (-0700)
Subject: mm/hugetlb: narrow the hugetlb_lock protection area during preparing huge page
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=2f37511cb6c2a59b67f8f13ad206a0298992eaf5;p=uclinux-h8%2Flinux.git

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.

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: https://lkml.kernel.org/r/20200831022351.20916-7-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a3aea2c1181b..a5068a38d8af 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1504,9 +1504,9 @@ static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 {
 	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);