On 11/6/19 12:28 AM, Kirill A. Shutemov wrote:
On Wed, Nov 06, 2019 at 01:03:36AM +0800, Yang Shi wrote:The __page_check_anon_rmap() just calls two BUG_ON()s protected by CONFIG_DEBUG_VM, the #ifdef could be eliminated by using VM_BUG_ON(). Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx> --- mm/rmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index d17cbf3..39178eb 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1055,7 +1055,6 @@ static void __page_set_anon_rmap(struct page *page, static void __page_check_anon_rmap(struct page *page, struct vm_area_struct *vma, unsigned long address) { -#ifdef CONFIG_DEBUG_VM /* * The page's anon-rmap details (mapping and index) are guaranteed to * be set up correctly at this point. @@ -1068,9 +1067,8 @@ static void __page_check_anon_rmap(struct page *page, * are initially only visible via the pagetables, and the pte is locked * over the call to page_add_new_anon_rmap. */ - BUG_ON(page_anon_vma(page)->root != vma->anon_vma->root); - BUG_ON(page_to_pgoff(page) != linear_page_index(vma, address)); -#endif + VM_BUG_ON(page_anon_vma(page)->root != vma->anon_vma->root); + VM_BUG_ON(page_to_pgoff(page) != linear_page_index(vma, address));Why not VM_BUG_ON_PAGE()?
Because I was not intended to change the behavior, just cleanup. We definitely could use VM_BUG_ON_PAGE() if that is preferred.
