On Thu, Sep 27, 2018 at 4:27 PM Alex Xu (Hello71) <alex_y_xu@xxxxxxxx> wrote:
>
> Spinlocks are always lockable on UP systems, even if they were just
> locked.
i think it would be much better to just use either
assert_spin_locked() or just spin_is_locked(), instead of an #ifdef.
>
> Cc: Dan Streetman <ddstreet@xxxxxxxx>
> Signed-off-by: Alex Xu (Hello71) <alex_y_xu@xxxxxxxx>
> ---
> mm/z3fold.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/mm/z3fold.c b/mm/z3fold.c
> index 4b366d181..4e6ad2de4 100644
> --- a/mm/z3fold.c
> +++ b/mm/z3fold.c
> @@ -202,6 +202,13 @@ static inline void z3fold_page_lock(struct z3fold_header *zhdr)
> spin_lock(&zhdr->page_lock);
> }
>
> +static inline void z3fold_page_ensure_locked(struct z3fold_header *zhdr)
> +{
> +#ifdef CONFIG_SMP
> + WARN_ON(z3fold_page_trylock(zhdr));
> +#endif
> +}
> +
> /* Try to lock a z3fold page */
> static inline int z3fold_page_trylock(struct z3fold_header *zhdr)
> {
> @@ -277,7 +284,7 @@ static void release_z3fold_page_locked(struct kref *ref)
> {
> struct z3fold_header *zhdr = container_of(ref, struct z3fold_header,
> refcount);
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> __release_z3fold_page(zhdr, true);
> }
>
> @@ -289,7 +296,7 @@ static void release_z3fold_page_locked_list(struct kref *ref)
> list_del_init(&zhdr->buddy);
> spin_unlock(&zhdr->pool->lock);
>
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> __release_z3fold_page(zhdr, true);
> }
>
> @@ -403,7 +410,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
>
> page = virt_to_page(zhdr);
> if (locked)
> - WARN_ON(z3fold_page_trylock(zhdr));
> + z3fold_page_ensure_locked(zhdr);
> else
> z3fold_page_lock(zhdr);
> if (WARN_ON(!test_and_clear_bit(NEEDS_COMPACTING, &page->private))) {
> --
> 2.19.0
>
