diff options
author | Sasha Levin <sasha.levin@oracle.com> | 2014-01-23 15:52:54 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-23 16:36:50 -0800 |
commit | 309381feaee564281c3d9e90fbca8963bb7428ad (patch) | |
tree | 7e9f990c0cffcb8c5fc90deb1c7eac445c5ada0e /mm/internal.h | |
parent | e3bba3c3c90cd434c1ccb9e5dc704a96baf9541c (diff) | |
download | lwn-309381feaee564281c3d9e90fbca8963bb7428ad.tar.gz lwn-309381feaee564281c3d9e90fbca8963bb7428ad.zip |
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>
Diffstat (limited to 'mm/internal.h')
-rw-r--r-- | mm/internal.h | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/internal.h b/mm/internal.h index a346ba120e42..dc95e979ae56 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -27,8 +27,8 @@ static inline void set_page_count(struct page *page, int v) */ static inline void set_page_refcounted(struct page *page) { - VM_BUG_ON(PageTail(page)); - VM_BUG_ON(atomic_read(&page->_count)); + VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(atomic_read(&page->_count), page); set_page_count(page, 1); } @@ -46,7 +46,7 @@ static inline void __get_page_tail_foll(struct page *page, * speculative page access (like in * page_cache_get_speculative()) on tail pages. */ - VM_BUG_ON(atomic_read(&page->first_page->_count) <= 0); + VM_BUG_ON_PAGE(atomic_read(&page->first_page->_count) <= 0, page); if (get_page_head) atomic_inc(&page->first_page->_count); get_huge_page_tail(page); @@ -71,7 +71,7 @@ static inline void get_page_foll(struct page *page) * Getting a normal page or the head of a compound page * requires to already have an elevated page->_count. */ - VM_BUG_ON(atomic_read(&page->_count) <= 0); + VM_BUG_ON_PAGE(atomic_read(&page->_count) <= 0, page); atomic_inc(&page->_count); } } @@ -173,7 +173,7 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma) static inline int mlocked_vma_newpage(struct vm_area_struct *vma, struct page *page) { - VM_BUG_ON(PageLRU(page)); + VM_BUG_ON_PAGE(PageLRU(page), page); if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED)) return 0; |