mm: dump page when hitting a VM_BUG_ON using VM_BUG_ON_PAGE

Most of the VM_BUG_ON assertions are performed on a page.  Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.

I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.

This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.

[akpm@linux-foundation.org: fix up includes]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 10 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eea668d9cff6..2254f36b74b8 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -603,7 +603,7 @@ void putback_lru_page(struct page *page)
         bool is_unevictable;
         int was_unevictable = PageUnevictable(page);
 
-        VM_BUG_ON(PageLRU(page));
+        VM_BUG_ON_PAGE(PageLRU(page), page);
 
 redo:
         ClearPageUnevictable(page);
@@ -794,8 +794,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
                 if (!trylock_page(page))
                         goto keep;
 
-                VM_BUG_ON(PageActive(page));
-                VM_BUG_ON(page_zone(page) != zone);
+                VM_BUG_ON_PAGE(PageActive(page), page);
+                VM_BUG_ON_PAGE(page_zone(page) != zone, page);
 
                 sc->nr_scanned++;
 
@@ -1079,14 +1079,14 @@ activate_locked:
                 /* Not a candidate for swapping, so reclaim swap space. */
                 if (PageSwapCache(page) && vm_swap_full())
                         try_to_free_swap(page);
-                VM_BUG_ON(PageActive(page));
+                VM_BUG_ON_PAGE(PageActive(page), page);
                 SetPageActive(page);
                 pgactivate++;
 keep_locked:
                 unlock_page(page);
 keep:
                 list_add(&page->lru, &ret_pages);
-                VM_BUG_ON(PageLRU(page) || PageUnevictable(page));
+                VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page), page);
         }
 
         free_hot_cold_page_list(&free_pages, 1);
@@ -1240,7 +1240,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                 page = lru_to_page(src);
                 prefetchw_prev_lru_page(page, src, flags);
 
-                VM_BUG_ON(!PageLRU(page));
+                VM_BUG_ON_PAGE(!PageLRU(page), page);
 
                 switch (__isolate_lru_page(page, mode)) {
                 case 0:
@@ -1295,7 +1295,7 @@ int isolate_lru_page(struct page *page)
 {
         int ret = -EBUSY;
 
-        VM_BUG_ON(!page_count(page));
+        VM_BUG_ON_PAGE(!page_count(page), page);
 
         if (PageLRU(page)) {
                 struct zone *zone = page_zone(page);
@@ -1366,7 +1366,7 @@ putback_inactive_pages(struct lruvec *lruvec, struct list_head *page_list)
                 struct page *page = lru_to_page(page_list);
                 int lru;
 
-                VM_BUG_ON(PageLRU(page));
+                VM_BUG_ON_PAGE(PageLRU(page), page);
                 list_del(&page->lru);
                 if (unlikely(!page_evictable(page))) {
                         spin_unlock_irq(&zone->lru_lock);
@@ -1586,7 +1586,7 @@ static void move_active_pages_to_lru(struct lruvec *lruvec,
                 page = lru_to_page(list);
                 lruvec = mem_cgroup_page_lruvec(page, zone);
 
-                VM_BUG_ON(PageLRU(page));
+                VM_BUG_ON_PAGE(PageLRU(page), page);
                 SetPageLRU(page);
 
                 nr_pages = hpage_nr_pages(page);
@@ -3701,7 +3701,7 @@ void check_move_unevictable_pages(struct page **pages, int nr_pages)
                 if (page_evictable(page)) {
                         enum lru_list lru = page_lru_base_type(page);
 
-                        VM_BUG_ON(PageActive(page));
+                        VM_BUG_ON_PAGE(PageActive(page), page);
                         ClearPageUnevictable(page);
                         del_page_from_lru_list(page, lruvec, LRU_UNEVICTABLE);
                         add_page_to_lru_list(page, lruvec, lru);