1 files changed, 106 insertions, 0 deletions

diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
new file mode 100644
index 000000000000..245900b98c8e
--- /dev/null
+++ b/lib/interval_tree_test.c
@@ -0,0 +1,106 @@
+#include <linux/module.h>
+#include <linux/interval_tree.h>
+#include <linux/random.h>
+#include <asm/timex.h>
+
+#define NODES        100
+#define PERF_LOOPS   100000
+#define SEARCHES     100
+#define SEARCH_LOOPS 10000
+
+static struct rb_root root = RB_ROOT;
+static struct interval_tree_node nodes[NODES];
+static u32 queries[SEARCHES];
+
+static struct rnd_state rnd;
+
+static inline unsigned long
+search(unsigned long query, struct rb_root *root)
+{
+        struct interval_tree_node *node;
+        unsigned long results = 0;
+
+        for (node = interval_tree_iter_first(root, query, query); node;
+             node = interval_tree_iter_next(node, query, query))
+                results++;
+        return results;
+}
+
+static void init(void)
+{
+        int i;
+        for (i = 0; i < NODES; i++) {
+                u32 a = prandom_u32_state(&rnd);
+                u32 b = prandom_u32_state(&rnd);
+                if (a <= b) {
+                        nodes[i].start = a;
+                        nodes[i].last = b;
+                } else {
+                        nodes[i].start = b;
+                        nodes[i].last = a;
+                }
+        }
+        for (i = 0; i < SEARCHES; i++)
+                queries[i] = prandom_u32_state(&rnd);
+}
+
+static int interval_tree_test_init(void)
+{
+        int i, j;
+        unsigned long results;
+        cycles_t time1, time2, time;
+
+        printk(KERN_ALERT "interval tree insert/remove");
+
+        prandom_seed_state(&rnd, 3141592653589793238ULL);
+        init();
+
+        time1 = get_cycles();
+
+        for (i = 0; i < PERF_LOOPS; i++) {
+                for (j = 0; j < NODES; j++)
+                        interval_tree_insert(nodes + j, &root);
+                for (j = 0; j < NODES; j++)
+                        interval_tree_remove(nodes + j, &root);
+        }
+
+        time2 = get_cycles();
+        time = time2 - time1;
+
+        time = div_u64(time, PERF_LOOPS);
+        printk(" -> %llu cycles\n", (unsigned long long)time);
+
+        printk(KERN_ALERT "interval tree search");
+
+        for (j = 0; j < NODES; j++)
+                interval_tree_insert(nodes + j, &root);
+
+        time1 = get_cycles();
+
+        results = 0;
+        for (i = 0; i < SEARCH_LOOPS; i++)
+                for (j = 0; j < SEARCHES; j++)
+                        results += search(queries[j], &root);
+
+        time2 = get_cycles();
+        time = time2 - time1;
+
+        time = div_u64(time, SEARCH_LOOPS);
+        results = div_u64(results, SEARCH_LOOPS);
+        printk(" -> %llu cycles (%lu results)\n",
+               (unsigned long long)time, results);
+
+        return -EAGAIN; /* Fail will directly unload the module */
+}
+
+static void interval_tree_test_exit(void)
+{
+        printk(KERN_ALERT "test exit\n");
+}
+
+module_init(interval_tree_test_init)
+module_exit(interval_tree_test_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Michel Lespinasse");
+MODULE_DESCRIPTION("Interval Tree test");