On 10/19/21 14:50, Matthew Wilcox (Oracle) wrote:
> Leave interrupts disabled when we change which lru lock is held.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Assuming lockdep is fine with e.g.:
spin_lock_irqsave(A);
spin_unlock(A);
spin_lock(B);
spin_unlock_irqrestore(B);
(with A and B of same class).
> ---
> include/linux/memcontrol.h | 27 ++++++++++++++-------------
> 1 file changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 3096c9a0ee01..a6a90b00a22b 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1524,16 +1524,22 @@ static inline bool page_matches_lruvec(struct page *page, struct lruvec *lruvec)
> }
>
> /* Don't lock again iff page's lruvec locked */
> -static inline struct lruvec *relock_page_lruvec_irq(struct page *page,
> +static inline struct lruvec *relock_page_lruvec(struct page *page,
> struct lruvec *locked_lruvec)
> {
> - if (locked_lruvec) {
> - if (page_matches_lruvec(page, locked_lruvec))
> - return locked_lruvec;
> + if (page_matches_lruvec(page, locked_lruvec))
> + return locked_lruvec;
>
> - unlock_page_lruvec_irq(locked_lruvec);
> - }
> + unlock_page_lruvec(locked_lruvec);
> + return lock_page_lruvec(page);
> +}
>
> +/* Don't lock again iff page's lruvec locked */
> +static inline struct lruvec *relock_page_lruvec_irq(struct page *page,
> + struct lruvec *locked_lruvec)
> +{
> + if (locked_lruvec)
> + return relock_page_lruvec(page, locked_lruvec);
> return lock_page_lruvec_irq(page);
> }
>
> @@ -1541,13 +1547,8 @@ static inline struct lruvec *relock_page_lruvec_irq(struct page *page,
> static inline struct lruvec *relock_page_lruvec_irqsave(struct page *page,
> struct lruvec *locked_lruvec, unsigned long *flags)
> {
> - if (locked_lruvec) {
> - if (page_matches_lruvec(page, locked_lruvec))
> - return locked_lruvec;
> -
> - unlock_page_lruvec_irqrestore(locked_lruvec, *flags);
> - }
> -
> + if (locked_lruvec)
> + return relock_page_lruvec(page, locked_lruvec);
> return lock_page_lruvec_irqsave(page, flags);
> }
>
>
