> if (next_deferred >= scanned)
> @@ -468,18 +487,9 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid,
> if (nr_scanned == 0)
> nr_scanned = SWAP_CLUSTER_MAX;
>
> - if (!down_read_trylock(&shrinker_rwsem)) {
> - /*
> - * If we would return 0, our callers would understand that we
> - * have nothing else to shrink and give up trying. By
> returning
> - * 1 we keep it going and assume we'll be able to shrink next
> - * time.
> - */
> - freed = 1;
> - goto out;
> - }
> + rcu_read_lock();
Sorry, the rcu_read_lock() will not work. I am currently testing with
srcu_read_lock() and see if it gives any error.
>
> - list_for_each_entry(shrinker, &shrinker_list, list) {
> + list_for_each_entry_rcu(shrinker, &shrinker_list, list) {
> struct shrink_control sc = {
> .gfp_mask = gfp_mask,
> .nid = nid,
> @@ -498,11 +508,13 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int
> nid,
> if (!(shrinker->flags & SHRINKER_NUMA_AWARE))
> sc.nid = 0;
>
> + get_shrinker(shrinker);
> freed += do_shrink_slab(&sc, shrinker, nr_scanned,
> nr_eligible);
> + put_shrinker(shrinker);
> }
>
> - up_read(&shrinker_rwsem);
> -out:
> + rcu_read_unlock();
> +
> cond_resched();
> return freed;
> }
> --
> 2.15.0.403.gc27cc4dac6-goog
>
