unsigned long bitmap; /* A zero bit means "space here" */
struct idr_layer *ary[1<<IDR_BITS];
int count; /* When zero, we can release it */
+ int layer; /* distance from leaf */
struct rcu_head rcu_head;
};
struct idr {
struct idr_layer *top;
struct idr_layer *id_free;
- int layers;
+ int layers; /* only valid without concurrent changes */
int id_free_cnt;
spinlock_t lock;
};