[PATCH 13/16] mm: Replace spin_is_locked() with lockdep

[Lance Roy]

lockdep_assert_held() is better suited to checking locking requirements,
since it won't get confused when someone else holds the lock. This is
also a step towards possibly removing spin_is_locked().

Signed-off-by: Lance Roy <ldr...@gmail.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Yang Shi <yang....@linux.alibaba.com>
Cc: Matthew Wilcox <mawil...@microsoft.com>
Cc: Mel Gorman <mgor...@techsingularity.net>
Cc: Vlastimil Babka <vba...@suse.cz>
Cc: Jan Kara <j...@suse.cz>
Cc: Shakeel Butt <shake...@google.com>
Cc: <linux...@kvack.org>
---
 mm/khugepaged.c | 4 ++--
 mm/swap.c       | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a31d740e6cd1..80f12467ccb3 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1225,7 +1225,7 @@ static void collect_mm_slot(struct mm_slot *mm_slot)
 {
        struct mm_struct *mm = mm_slot->mm;
 
-       VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+       lockdep_assert_held(&khugepaged_mm_lock);
 
        if (khugepaged_test_exit(mm)) {
                /* free mm_slot */
@@ -1665,7 +1665,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int 
pages,
        int progress = 0;
 
        VM_BUG_ON(!pages);
-       VM_BUG_ON(NR_CPUS != 1 && !spin_is_locked(&khugepaged_mm_lock));
+       lockdep_assert_held(&khugepaged_mm_lock);
 
        if (khugepaged_scan.mm_slot)
                mm_slot = khugepaged_scan.mm_slot;
diff --git a/mm/swap.c b/mm/swap.c
index 26fc9b5f1b6c..c89eb442c0bf 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -824,8 +824,7 @@ void lru_add_page_tail(struct page *page, struct page 
*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_pgdat(lruvec)->lru_lock));
+       lockdep_assert_held(&lruvec_pgdat(lruvec)->lru_lock);
 
        if (!list)
                SetPageLRU(page_tail);
-- 
2.19.0