1 files changed, 139 insertions, 0 deletions
diff --git a/lib/interval_tree_test.c b/lib/interval_tree_test.c
new file mode 100644
index 0000000000..f37f4d44fa
--- /dev/null
+++ b/lib/interval_tree_test.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/interval_tree.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <asm/timex.h>
+
+#define __param(type, name, init, msg)		\
+	static type name = init;		\
+	module_param(name, type, 0444);		\
+	MODULE_PARM_DESC(name, msg);
+
+__param(int, nnodes, 100, "Number of nodes in the interval tree");
+__param(int, perf_loops, 1000, "Number of iterations modifying the tree");
+
+__param(int, nsearches, 100, "Number of searches to the interval tree");
+__param(int, search_loops, 1000, "Number of iterations searching the tree");
+__param(bool, search_all, false, "Searches will iterate all nodes in the tree");
+
+__param(uint, max_endpoint, ~0, "Largest value for the interval's endpoint");
+
+static struct rb_root_cached root = RB_ROOT_CACHED;
+static struct interval_tree_node *nodes = NULL;
+static u32 *queries = NULL;
+
+static struct rnd_state rnd;
+
+static inline unsigned long
+search(struct rb_root_cached *root, unsigned long start, unsigned long last)
+{
+	struct interval_tree_node *node;
+	unsigned long results = 0;
+
+	for (node = interval_tree_iter_first(root, start, last); node;
+	     node = interval_tree_iter_next(node, start, last))
+		results++;
+	return results;
+}
+
+static void init(void)
+{
+	int i;
+
+	for (i = 0; i < nnodes; i++) {
+		u32 b = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
+		u32 a = (prandom_u32_state(&rnd) >> 4) % b;
+
+		nodes[i].start = a;
+		nodes[i].last = b;
+	}
+
+	/*
+	 * Limit the search scope to what the user defined.
+	 * Otherwise we are merely measuring empty walks,
+	 * which is pointless.
+	 */
+	for (i = 0; i < nsearches; i++)
+		queries[i] = (prandom_u32_state(&rnd) >> 4) % max_endpoint;
+}
+
+static int interval_tree_test_init(void)
+{
+	int i, j;
+	unsigned long results;
+	cycles_t time1, time2, time;
+
+	nodes = kmalloc_array(nnodes, sizeof(struct interval_tree_node),
+			      GFP_KERNEL);
+	if (!nodes)
+		return -ENOMEM;
+
+	queries = kmalloc_array(nsearches, sizeof(int), GFP_KERNEL);
+	if (!queries) {
+		kfree(nodes);
+		return -ENOMEM;
+	}
+
+	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 < nnodes; j++)
+			interval_tree_insert(nodes + j, &root);
+		for (j = 0; j < nnodes; 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 < nnodes; j++)
+		interval_tree_insert(nodes + j, &root);
+
+	time1 = get_cycles();
+
+	results = 0;
+	for (i = 0; i < search_loops; i++)
+		for (j = 0; j < nsearches; j++) {
+			unsigned long start = search_all ? 0 : queries[j];
+			unsigned long last = search_all ? max_endpoint : queries[j];
+
+			results += search(&root, start, last);
+		}
+
+	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);
+
+	kfree(queries);
+	kfree(nodes);
+
+	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");