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/hugetlb.c b/mm/hugetlb.c
index 04306b9..c01cb9f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -584,7 +584,7 @@
1 << PG_active | 1 << PG_reserved |
1 << PG_private | 1 << PG_writeback);
}
- VM_BUG_ON(hugetlb_cgroup_from_page(page));
+ VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page);
set_compound_page_dtor(page, NULL);
set_page_refcounted(page);
arch_release_hugepage(page);
@@ -1089,7 +1089,7 @@
* no users -- drop the buddy allocator's reference.
*/
put_page_testzero(page);
- VM_BUG_ON(page_count(page));
+ VM_BUG_ON_PAGE(page_count(page), page);
enqueue_huge_page(h, page);
}
free:
@@ -3503,7 +3503,7 @@
bool isolate_huge_page(struct page *page, struct list_head *list)
{
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
if (!get_page_unless_zero(page))
return false;
spin_lock(&hugetlb_lock);
@@ -3514,7 +3514,7 @@
void putback_active_hugepage(struct page *page)
{
- VM_BUG_ON(!PageHead(page));
+ VM_BUG_ON_PAGE(!PageHead(page), page);
spin_lock(&hugetlb_lock);
list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
spin_unlock(&hugetlb_lock);
@@ -3523,7 +3523,7 @@
bool is_hugepage_active(struct page *page)
{
- VM_BUG_ON(!PageHuge(page));
+ VM_BUG_ON_PAGE(!PageHuge(page), page);
/*
* This function can be called for a tail page because the caller,
* scan_movable_pages, scans through a given pfn-range which typically