On 10/3/18 7:38 AM, Lance Roy wrote:
> 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().
Agreed
> 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>
Acked-by: Vlastimil Babka <vba...@suse.cz>
> ---
> 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);
>
