[PATCH 3/6] mm, hwpoison: use num_poisoned_pages_sub() to decrease num_poisoned_pages

[Miaohe Lin <linmiaohe@huawei.com>]

Use num_poisoned_pages_sub() to combine multiple atomic ops into one. Also
num_poisoned_pages_dec() can be killed as there's no caller now.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 include/linux/swapops.h | 5 -----
 mm/memory-failure.c     | 6 ++++--
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index dbf9df854124..86b95ccb81bb 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -602,11 +602,6 @@ static inline void num_poisoned_pages_inc(void)
 	atomic_long_inc(&num_poisoned_pages);
 }
 
-static inline void num_poisoned_pages_dec(void)
-{
-	atomic_long_dec(&num_poisoned_pages);
-}
-
 static inline void num_poisoned_pages_sub(long i)
 {
 	atomic_long_sub(i, &num_poisoned_pages);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 3966fa6abe03..69c4d1b48ad6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -2596,7 +2596,7 @@ int soft_offline_page(unsigned long pfn, int flags)
 
 void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 {
-	int i;
+	int i, total = 0;
 
 	/*
 	 * A further optimization is to have per section refcounted
@@ -2609,8 +2609,10 @@ void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 
 	for (i = 0; i < nr_pages; i++) {
 		if (PageHWPoison(&memmap[i])) {
-			num_poisoned_pages_dec();
+			total++;
 			ClearPageHWPoison(&memmap[i]);
 		}
 	}
+	if (total)
+		num_poisoned_pages_sub(total);
 }
-- 
2.23.0