+static inline void *idr_mk_value(unsigned long v)
+{
+ BUG_ON((long)v < 0);
+ return (void *)((v & 1) | 2 | (v << 1));
+}
+
+DEFINE_IDR(find_idr);
+
+static void *idr_throbber(void *arg)
+{
+ time_t start = time(NULL);
+ int id = *(int *)arg;
+
+ rcu_register_thread();
+ do {
+ idr_alloc(&find_idr, idr_mk_value(id), id, id + 1, GFP_KERNEL);
+ idr_remove(&find_idr, id);
+ } while (time(NULL) < start + 10);
+ rcu_unregister_thread();
+
+ return NULL;
+}
+
+void idr_find_test_1(int anchor_id, int throbber_id)
+{
+ pthread_t throbber;
+ time_t start = time(NULL);
+
+ pthread_create(&throbber, NULL, idr_throbber, &throbber_id);
+
+ BUG_ON(idr_alloc(&find_idr, idr_mk_value(anchor_id), anchor_id,
+ anchor_id + 1, GFP_KERNEL) != anchor_id);
+
+ do {
+ int id = 0;
+ void *entry = idr_get_next(&find_idr, &id);
+ BUG_ON(entry != idr_mk_value(id));
+ } while (time(NULL) < start + 11);
+
+ pthread_join(throbber, NULL);
+
+ idr_remove(&find_idr, anchor_id);
+ BUG_ON(!idr_is_empty(&find_idr));
+}
+
+void idr_find_test(void)
+{
+ idr_find_test_1(100000, 0);
+ idr_find_test_1(0, 100000);
+}
+