[PATCH 1/4] mm/page_alloc.c: extract commom part to check page

Wei Yang
2020-01-19T13:14:35Z

During free and new page, we did some check on the status of page
struct.

There is some common part, just extract them.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
mm/page_alloc.c | 36 ++++++++++++++++--------------------
1 file changed, 16 insertions(+), 20 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d047bf7d8fd4..8cd06729169f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1025,13 +1025,9 @@ static inline bool page_expected_state(struct page *page,
return true;
}

-static void free_pages_check_bad(struct page *page)
+static inline const char *__check_page(struct page *page)
{
- const char *bad_reason;
- unsigned long bad_flags;
-
- bad_reason = NULL;
- bad_flags = 0;
+ const char *bad_reason = NULL;

if (unlikely(atomic_read(&page->_mapcount) != -1))
bad_reason = "nonzero mapcount";
@@ -1039,14 +1035,23 @@ static void free_pages_check_bad(struct page *page)
bad_reason = "non-NULL mapping";
if (unlikely(page_ref_count(page) != 0))
bad_reason = "nonzero _refcount";
- if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
- bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
- bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
- }
#ifdef CONFIG_MEMCG
if (unlikely(page->mem_cgroup))
bad_reason = "page still charged to cgroup";
#endif
+ return bad_reason;
+}
+
+static void free_pages_check_bad(struct page *page)
+{
+ const char *bad_reason = NULL;
+ unsigned long bad_flags = 0;
+
+ bad_reason = __check_page(page);
+ if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_FREE)) {
+ bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
+ bad_flags = PAGE_FLAGS_CHECK_AT_FREE;
+ }
bad_page(page, bad_reason, bad_flags);
}

@@ -2044,12 +2049,7 @@ static void check_new_page_bad(struct page *page)
const char *bad_reason = NULL;
unsigned long bad_flags = 0;

- if (unlikely(atomic_read(&page->_mapcount) != -1))
- bad_reason = "nonzero mapcount";
- if (unlikely(page->mapping != NULL))
- bad_reason = "non-NULL mapping";
- if (unlikely(page_ref_count(page) != 0))
- bad_reason = "nonzero _refcount";
+ bad_reason = __check_page(page);
if (unlikely(page->flags & __PG_HWPOISON)) {
bad_reason = "HWPoisoned (hardware-corrupted)";
bad_flags = __PG_HWPOISON;
@@ -2061,10 +2061,6 @@ static void check_new_page_bad(struct page *page)
bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";
bad_flags = PAGE_FLAGS_CHECK_AT_PREP;
}
-#ifdef CONFIG_MEMCG
- if (unlikely(page->mem_cgroup))
- bad_reason = "page still charged to cgroup";
-#endif
bad_page(page, bad_reason, bad_flags);
}

--
2.17.1