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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 /mm/ksm.c | |
| parent | e3bba3c3c90cd434c1ccb9e5dc704a96baf9541c (diff) | |
| download | linux-309381feaee564281c3d9e90fbca8963bb7428ad.tar.gz | |
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.c | 12 |
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() |