diff mbox series

[07/11] mm: VM_BUG_ON lru page flags

Message ID 20201207220949.830352-8-yuzhao@google.com (mailing list archive)
State New, archived
Headers show
Series mm: lru related cleanups | expand

Commit Message

Yu Zhao Dec. 7, 2020, 10:09 p.m. UTC
Move scattered VM_BUG_ONs to two essential places that cover all
lru list additions and deletions.

Signed-off-by: Yu Zhao <yuzhao@google.com>
---
 include/linux/mm_inline.h | 4 ++++
 mm/swap.c                 | 2 --
 mm/vmscan.c               | 1 -
 3 files changed, 4 insertions(+), 3 deletions(-)

Comments

Matthew Wilcox Dec. 7, 2020, 10:24 p.m. UTC | #1
On Mon, Dec 07, 2020 at 03:09:45PM -0700, Yu Zhao wrote:
> Move scattered VM_BUG_ONs to two essential places that cover all
> lru list additions and deletions.

I'd like to see these converted into VM_BUG_ON_PGFLAGS so you have
to take that extra CONFIG step to enable checking them.
Yu Zhao Dec. 16, 2020, 12:54 a.m. UTC | #2
On Mon, Dec 07, 2020 at 10:24:29PM +0000, Matthew Wilcox wrote:
> On Mon, Dec 07, 2020 at 03:09:45PM -0700, Yu Zhao wrote:
> > Move scattered VM_BUG_ONs to two essential places that cover all
> > lru list additions and deletions.
> 
> I'd like to see these converted into VM_BUG_ON_PGFLAGS so you have
> to take that extra CONFIG step to enable checking them.

Right. I'll make sure it won't slip my mind again in v2.
Matthew Wilcox Dec. 16, 2020, 12:59 a.m. UTC | #3
On Tue, Dec 15, 2020 at 05:54:51PM -0700, Yu Zhao wrote:
> On Mon, Dec 07, 2020 at 10:24:29PM +0000, Matthew Wilcox wrote:
> > On Mon, Dec 07, 2020 at 03:09:45PM -0700, Yu Zhao wrote:
> > > Move scattered VM_BUG_ONs to two essential places that cover all
> > > lru list additions and deletions.
> > 
> > I'd like to see these converted into VM_BUG_ON_PGFLAGS so you have
> > to take that extra CONFIG step to enable checking them.
> 
> Right. I'll make sure it won't slip my mind again in v2.

Hugh has enlightened me that VM_BUG_ON_PGFLAGS() should not be used for
this purpose.  Sorry for the bad recommendation.
diff mbox series

Patch

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index ef3fd79222e5..6d907a4dd6ad 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -66,6 +66,8 @@  static inline enum lru_list page_lru_base_type(struct page *page)
  */
 static __always_inline void __clear_page_lru_flags(struct page *page)
 {
+	VM_BUG_ON_PAGE(!PageLRU(page), page);
+
 	__ClearPageLRU(page);
 
 	/* this shouldn't happen, so leave the flags to bad_page() */
@@ -87,6 +89,8 @@  static __always_inline enum lru_list page_lru(struct page *page)
 {
 	enum lru_list lru;
 
+	VM_BUG_ON_PAGE(PageActive(page) && PageUnevictable(page), page);
+
 	if (PageUnevictable(page))
 		lru = LRU_UNEVICTABLE;
 	else {
diff --git a/mm/swap.c b/mm/swap.c
index a37c896a32b0..09c4a48e0bcd 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -83,7 +83,6 @@  static void __page_cache_release(struct page *page)
 		unsigned long flags;
 
 		lruvec = lock_page_lruvec_irqsave(page, &flags);
-		VM_BUG_ON_PAGE(!PageLRU(page), page);
 		del_page_from_lru_list(page, lruvec);
 		__clear_page_lru_flags(page);
 		unlock_page_lruvec_irqrestore(lruvec, flags);
@@ -909,7 +908,6 @@  void release_pages(struct page **pages, int nr)
 			if (prev_lruvec != lruvec)
 				lock_batch = 0;
 
-			VM_BUG_ON_PAGE(!PageLRU(page), page);
 			del_page_from_lru_list(page, lruvec);
 			__clear_page_lru_flags(page);
 		}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index e6bdfdfa2da1..95e581c9d9af 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4279,7 +4279,6 @@  void check_move_unevictable_pages(struct pagevec *pvec)
 
 		lruvec = relock_page_lruvec_irq(page, lruvec);
 		if (page_evictable(page) && PageUnevictable(page)) {
-			VM_BUG_ON_PAGE(PageActive(page), page);
 			del_page_from_lru_list(page, lruvec);
 			ClearPageUnevictable(page);
 			add_page_to_lru_list(page, lruvec);