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authorSasha Levin <sasha.levin@oracle.com>2014-01-23 15:52:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-23 16:36:50 -0800
commit309381feaee564281c3d9e90fbca8963bb7428ad (patch)
tree7e9f990c0cffcb8c5fc90deb1c7eac445c5ada0e /mm/ksm.c
parente3bba3c3c90cd434c1ccb9e5dc704a96baf9541c (diff)
downloadlinux-309381feaee564281c3d9e90fbca8963bb7428ad.tar.bz2
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/ksm.c')
-rw-r--r--mm/ksm.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/mm/ksm.c b/mm/ksm.c
index 3df141e5f3e0..f91ddf5c3688 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1898,13 +1898,13 @@ int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
int ret = SWAP_AGAIN;
int search_new_forks = 0;
- VM_BUG_ON(!PageKsm(page));
+ VM_BUG_ON_PAGE(!PageKsm(page), page);
/*
* Rely on the page lock to protect against concurrent modifications
* to that page's node of the stable tree.
*/
- VM_BUG_ON(!PageLocked(page));
+ VM_BUG_ON_PAGE(!PageLocked(page), page);
stable_node = page_stable_node(page);
if (!stable_node)
@@ -1958,13 +1958,13 @@ void ksm_migrate_page(struct page *newpage, struct page *oldpage)
{
struct stable_node *stable_node;
- VM_BUG_ON(!PageLocked(oldpage));
- VM_BUG_ON(!PageLocked(newpage));
- VM_BUG_ON(newpage->mapping != oldpage->mapping);
+ VM_BUG_ON_PAGE(!PageLocked(oldpage), oldpage);
+ VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
+ VM_BUG_ON_PAGE(newpage->mapping != oldpage->mapping, newpage);
stable_node = page_stable_node(newpage);
if (stable_node) {
- VM_BUG_ON(stable_node->kpfn != page_to_pfn(oldpage));
+ VM_BUG_ON_PAGE(stable_node->kpfn != page_to_pfn(oldpage), oldpage);
stable_node->kpfn = page_to_pfn(newpage);
/*
* newpage->mapping was set in advance; now we need smp_wmb()