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/migrate.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'mm/migrate.c') diff --git a/mm/migrate.c b/mm/migrate.c index a8025befc323..4b3996eb7f0f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -499,7 +499,7 @@ void migrate_page_copy(struct page *newpage, struct page *page) if (PageUptodate(page)) SetPageUptodate(newpage); if (TestClearPageActive(page)) { - VM_BUG_ON(PageUnevictable(page)); + VM_BUG_ON_PAGE(PageUnevictable(page), page); SetPageActive(newpage); } else if (TestClearPageUnevictable(page)) SetPageUnevictable(newpage); @@ -871,7 +871,7 @@ static int __unmap_and_move(struct page *page, struct page *newpage, * free the metadata, so the page can be freed. */ if (!page->mapping) { - VM_BUG_ON(PageAnon(page)); + VM_BUG_ON_PAGE(PageAnon(page), page); if (page_has_private(page)) { try_to_free_buffers(page); goto uncharge; @@ -1618,7 +1618,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page) { int page_lru; - VM_BUG_ON(compound_order(page) && !PageTransHuge(page)); + VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page); /* Avoid migrating to a node that is nearly full */ if (!migrate_balanced_pgdat(pgdat, 1UL << compound_order(page))) -- cgit v1.2.3-59-g8ed1b