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 a3aea2c..a5068a3 100644 (file)
--- 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);