From: qiwuchen55@gmail.com
To: akpm@linux-foundation.org
Cc: linux-mm@kvack.org, chenqiwu <chenqiwu@xiaomi.com>
Subject: [PATCH] mm/memory: add refcount for special mapping page in copy_one_pte()
Date: Fri, 17 Apr 2020 18:31:54 +0800 [thread overview]
Message-ID: <1587119514-29679-1-git-send-email-qiwuchen55@gmail.com> (raw)
From: chenqiwu <chenqiwu@xiaomi.com>
If we get a special mapping page like device mapping page or zero page
when copy_one_pte, it's necessary add the page refcount count.
Signed-off-by: chenqiwu <chenqiwu@xiaomi.com>
---
mm/memory.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index f703fe8..a57975a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -802,8 +802,9 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
get_page(page);
page_dup_rmap(page, false);
rss[mm_counter(page)]++;
- } else if (pte_devmap(pte)) {
+ } else if (pte_devmap(pte) || is_zero_pfn(pte_pfn(pte))) {
page = pte_page(pte);
+ get_page(page);
}
out_set_pte:
--
1.9.1
next reply other threads:[~2020-04-17 10:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-17 10:31 qiwuchen55 [this message]
2020-04-17 11:43 ` Michal Hocko
2020-04-17 14:26 ` chenqiwu
2020-04-17 14:45 ` Matthew Wilcox
2020-04-17 15:23 ` Michal Hocko
2020-04-18 3:12 ` chenqiwu
2020-04-20 7:42 ` Michal Hocko
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