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>
diff --git a/mm/migrate.c b/mm/migrate.c
index a8025be..4b3996e 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -499,7 +499,7 @@
if (PageUptodate(page))
SetPageUptodate(newpage);
if (TestClearPageActive(page)) {
- VM_BUG_ON(PageUnevictable(page));
+ VM_BUG_ON_PAGE(PageUnevictable(page), page);
SetPageActive(newpage);
} else if (TestClearPageUnevictable(page))
SetPageUnevictable(newpage);
@@ -871,7 +871,7 @@
* free the metadata, so the page can be freed.
*/
if (!page->mapping) {
- VM_BUG_ON(PageAnon(page));
+ VM_BUG_ON_PAGE(PageAnon(page), page);
if (page_has_private(page)) {
try_to_free_buffers(page);
goto uncharge;
@@ -1618,7 +1618,7 @@
{
int page_lru;
- VM_BUG_ON(compound_order(page) && !PageTransHuge(page));
+ VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
/* Avoid migrating to a node that is nearly full */
if (!migrate_balanced_pgdat(pgdat, 1UL << compound_order(page)))