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| 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 /include/linux/mmdebug.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 'include/linux/mmdebug.h')
| -rw-r--r-- | include/linux/mmdebug.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h index 580bd587d916..5042c036dda9 100644 --- a/include/linux/mmdebug.h +++ b/include/linux/mmdebug.h @@ -1,10 +1,19 @@ #ifndef LINUX_MM_DEBUG_H #define LINUX_MM_DEBUG_H 1 +struct page; + +extern void dump_page(struct page *page, char *reason); +extern void dump_page_badflags(struct page *page, char *reason, + unsigned long badflags); + #ifdef CONFIG_DEBUG_VM #define VM_BUG_ON(cond) BUG_ON(cond) +#define VM_BUG_ON_PAGE(cond, page) \ + do { if (unlikely(cond)) { dump_page(page, NULL); BUG(); } } while (0) #else #define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond) +#define VM_BUG_ON_PAGE(cond, page) VM_BUG_ON(cond) #endif #ifdef CONFIG_DEBUG_VIRTUAL |