On Sat, Mar 11, 2017 at 12:22:12AM +0300, Alexey Khoroshilov wrote:
> Hello!
>
> z3fold_reclaim_page() contains the only return that may
> leave the function with pool->lock spinlock held.
>
> 669 spin_lock(&pool->lock);
> 670 if (kref_put(&zhdr->refcount, release_z3fold_page)) {
> 671 atomic64_dec(&pool->pages_nr);
> 672 return 0;
> 673 }
>
> May be we need spin_unlock(&pool->lock); just before return?
I would tend to agree. sparse warns about this, and also about two
other locking problems ... which I'm not sure are really problems so
much as missing annotations?
mm/z3fold.c:467:35: warning: context imbalance in 'z3fold_alloc' - unexpected
unlock
mm/z3fold.c:519:26: warning: context imbalance in 'z3fold_free' - different
lock contexts for basic block
mm/z3fold.c:581:12: warning: context imbalance in 'z3fold_reclaim_page' -
different lock contexts for basic block
