From 309381feaee564281c3d9e90fbca8963bb7428ad Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Thu, 23 Jan 2014 15:52:54 -0800 Subject: 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 Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/swap.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) (limited to 'mm/swap.c') diff --git a/mm/swap.c b/mm/swap.c index d1100b6..b31ba67 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -57,7 +57,7 @@ static void __page_cache_release(struct page *page) spin_lock_irqsave(&zone->lru_lock, flags); lruvec = mem_cgroup_page_lruvec(page, zone); - VM_BUG_ON(!PageLRU(page)); + VM_BUG_ON_PAGE(!PageLRU(page), page); __ClearPageLRU(page); del_page_from_lru_list(page, lruvec, page_off_lru(page)); spin_unlock_irqrestore(&zone->lru_lock, flags); @@ -130,8 +130,8 @@ static void put_compound_page(struct page *page) * __split_huge_page_refcount cannot race * here. */ - VM_BUG_ON(!PageHead(page_head)); - VM_BUG_ON(page_mapcount(page) != 0); + VM_BUG_ON_PAGE(!PageHead(page_head), page_head); + VM_BUG_ON_PAGE(page_mapcount(page) != 0, page); if (put_page_testzero(page_head)) { /* * If this is the tail of a slab @@ -148,7 +148,7 @@ static void put_compound_page(struct page *page) * the compound page enters the buddy * allocator. */ - VM_BUG_ON(PageSlab(page_head)); + VM_BUG_ON_PAGE(PageSlab(page_head), page_head); __put_compound_page(page_head); } return; @@ -199,7 +199,7 @@ out_put_single: __put_single_page(page); return; } - VM_BUG_ON(page_head != page->first_page); + VM_BUG_ON_PAGE(page_head != page->first_page, page); /* * We can release the refcount taken by * get_page_unless_zero() now that @@ -207,12 +207,12 @@ out_put_single: * compound_lock. */ if (put_page_testzero(page_head)) - VM_BUG_ON(1); + VM_BUG_ON_PAGE(1, page_head); /* __split_huge_page_refcount will wait now */ - VM_BUG_ON(page_mapcount(page) <= 0); + VM_BUG_ON_PAGE(page_mapcount(page) <= 0, page); atomic_dec(&page->_mapcount); - VM_BUG_ON(atomic_read(&page_head->_count) <= 0); - VM_BUG_ON(atomic_read(&page->_count) != 0); + VM_BUG_ON_PAGE(atomic_read(&page_head->_count) <= 0, page_head); + VM_BUG_ON_PAGE(atomic_read(&page->_count) != 0, page); compound_unlock_irqrestore(page_head, flags); if (put_page_testzero(page_head)) { @@ -223,7 +223,7 @@ out_put_single: } } else { /* page_head is a dangling pointer */ - VM_BUG_ON(PageTail(page)); + VM_BUG_ON_PAGE(PageTail(page), page); goto out_put_single; } } @@ -264,7 +264,7 @@ bool __get_page_tail(struct page *page) * page. __split_huge_page_refcount * cannot race here. */ - VM_BUG_ON(!PageHead(page_head)); + VM_BUG_ON_PAGE(!PageHead(page_head), page_head); __get_page_tail_foll(page, true); return true; } else { @@ -604,8 +604,8 @@ EXPORT_SYMBOL(__lru_cache_add); */ void lru_cache_add(struct page *page) { - VM_BUG_ON(PageActive(page) && PageUnevictable(page)); - VM_BUG_ON(PageLRU(page)); + VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page); + VM_BUG_ON_PAGE(PageLRU(page), page); __lru_cache_add(page); } @@ -846,7 +846,7 @@ void release_pages(struct page **pages, int nr, int cold) } lruvec = mem_cgroup_page_lruvec(page, zone); - VM_BUG_ON(!PageLRU(page)); + VM_BUG_ON_PAGE(!PageLRU(page), page); __ClearPageLRU(page); del_page_from_lru_list(page, lruvec, page_off_lru(page)); } @@ -888,9 +888,9 @@ void lru_add_page_tail(struct page *page, struct page *page_tail, { const int file = 0; - VM_BUG_ON(!PageHead(page)); - VM_BUG_ON(PageCompound(page_tail)); - VM_BUG_ON(PageLRU(page_tail)); + VM_BUG_ON_PAGE(!PageHead(page), page); + VM_BUG_ON_PAGE(PageCompound(page_tail), page); + VM_BUG_ON_PAGE(PageLRU(page_tail), page); VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&lruvec_zone(lruvec)->lru_lock)); @@ -929,7 +929,7 @@ static void __pagevec_lru_add_fn(struct page *page, struct lruvec *lruvec, int active = PageActive(page); enum lru_list lru = page_lru(page); - VM_BUG_ON(PageLRU(page)); + VM_BUG_ON_PAGE(PageLRU(page), page); SetPageLRU(page); add_page_to_lru_list(page, lruvec, lru); -- cgit v1.1