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_state.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'mm/swap_state.c') diff --git a/mm/swap_state.c b/mm/swap_state.c index e6f15f8ca2af..98e85e9c2b2d 100644 --- a/mm/swap_state.c +++ b/mm/swap_state.c @@ -83,9 +83,9 @@ int __add_to_swap_cache(struct page *page, swp_entry_t entry) int error; struct address_space *address_space; - VM_BUG_ON(!PageLocked(page)); - VM_BUG_ON(PageSwapCache(page)); - VM_BUG_ON(!PageSwapBacked(page)); + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(PageSwapCache(page), page); + VM_BUG_ON_PAGE(!PageSwapBacked(page), page); page_cache_get(page); SetPageSwapCache(page); @@ -139,9 +139,9 @@ void __delete_from_swap_cache(struct page *page) swp_entry_t entry; struct address_space *address_space; - VM_BUG_ON(!PageLocked(page)); - VM_BUG_ON(!PageSwapCache(page)); - VM_BUG_ON(PageWriteback(page)); + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(!PageSwapCache(page), page); + VM_BUG_ON_PAGE(PageWriteback(page), page); entry.val = page_private(page); address_space = swap_address_space(entry); @@ -165,8 +165,8 @@ int add_to_swap(struct page *page, struct list_head *list) swp_entry_t entry; int err; - VM_BUG_ON(!PageLocked(page)); - VM_BUG_ON(!PageUptodate(page)); + VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_PAGE(!PageUptodate(page), page); entry = get_swap_page(); if (!entry.val) -- cgit v1.2.3