linux-kernel - [PATCH v7 3/7] mm,hugetlb: Clear HPageFreed outside of the lock

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Date:   Tue, 13 Apr 2021 12:47:43 +0200
From:   Oscar Salvador <osalvador@...e.de>
To:     Andrew Morton <akpm@...ux-foundation.org>
Cc:     Mike Kravetz <mike.kravetz@...cle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        David Hildenbrand <david@...hat.com>,
        Michal Hocko <mhocko@...nel.org>,
        Muchun Song <songmuchun@...edance.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Oscar Salvador <osalvador@...e.de>
Subject: [PATCH v7 3/7] mm,hugetlb: Clear HPageFreed outside of the lock

Currently, the clearing of the flag is done under the lock, but this
is unnecessary as we just allocated the page and we did not give it
away yet, so no one should be messing with it.

Also, this helps making clear that here the lock is only protecting the
counter.

Signed-off-by: Oscar Salvador <osalvador@...e.de>
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 54d81d5947ed..e40d5fe5c63c 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1490,10 +1490,10 @@ static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 	hugetlb_set_page_subpool(page, NULL);
 	set_hugetlb_cgroup(page, NULL);
 	set_hugetlb_cgroup_rsvd(page, NULL);
+	ClearHPageFreed(page);
 	spin_lock_irq(&hugetlb_lock);
 	h->nr_huge_pages++;
 	h->nr_huge_pages_node[nid]++;
-	ClearHPageFreed(page);
 	spin_unlock_irq(&hugetlb_lock);
 }
 
-- 
2.16.3