1 files changed, 406 insertions, 0 deletions

diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
new file mode 100644
index 000000000000..8c1ad1ced72c
--- /dev/null
+++ b/lib/test_rhashtable.c
@@ -0,0 +1,406 @@
+/*
+ * Resizable, Scalable, Concurrent Hash Table
+ *
+ * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch>
+ * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/**************************************************************************
+ * Self Test
+ **************************************************************************/
+
+#include <linux/init.h>
+#include <linux/jhash.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/rcupdate.h>
+#include <linux/rhashtable.h>
+#include <linux/semaphore.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+
+#define MAX_ENTRIES	1000000
+#define TEST_INSERT_FAIL INT_MAX
+
+static int entries = 50000;
+module_param(entries, int, 0);
+MODULE_PARM_DESC(entries, "Number of entries to add (default: 50000)");
+
+static int runs = 4;
+module_param(runs, int, 0);
+MODULE_PARM_DESC(runs, "Number of test runs per variant (default: 4)");
+
+static int max_size = 65536;
+module_param(max_size, int, 0);
+MODULE_PARM_DESC(runs, "Maximum table size (default: 65536)");
+
+static bool shrinking = false;
+module_param(shrinking, bool, 0);
+MODULE_PARM_DESC(shrinking, "Enable automatic shrinking (default: off)");
+
+static int size = 8;
+module_param(size, int, 0);
+MODULE_PARM_DESC(size, "Initial size hint of table (default: 8)");
+
+static int tcount = 10;
+module_param(tcount, int, 0);
+MODULE_PARM_DESC(tcount, "Number of threads to spawn (default: 10)");
+
+struct test_obj {
+	int			value;
+	struct rhash_head	node;
+};
+
+struct thread_data {
+	int id;
+	struct task_struct *task;
+	struct test_obj *objs;
+};
+
+static struct test_obj array[MAX_ENTRIES];
+
+static struct rhashtable_params test_rht_params = {
+	.head_offset = offsetof(struct test_obj, node),
+	.key_offset = offsetof(struct test_obj, value),
+	.key_len = sizeof(int),
+	.hashfn = jhash,
+	.nulls_base = (3U << RHT_BASE_SHIFT),
+};
+
+static struct semaphore prestart_sem;
+static struct semaphore startup_sem = __SEMAPHORE_INITIALIZER(startup_sem, 0);
+
+static int __init test_rht_lookup(struct rhashtable *ht)
+{
+	unsigned int i;
+
+	for (i = 0; i < entries * 2; i++) {
+		struct test_obj *obj;
+		bool expected = !(i % 2);
+		u32 key = i;
+
+		if (array[i / 2].value == TEST_INSERT_FAIL)
+			expected = false;
+
+		obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
+
+		if (expected && !obj) {
+			pr_warn("Test failed: Could not find key %u\n", key);
+			return -ENOENT;
+		} else if (!expected && obj) {
+			pr_warn("Test failed: Unexpected entry found for key %u\n",
+				key);
+			return -EEXIST;
+		} else if (expected && obj) {
+			if (obj->value != i) {
+				pr_warn("Test failed: Lookup value mismatch %u!=%u\n",
+					obj->value, i);
+				return -EINVAL;
+			}
+		}
+
+		cond_resched_rcu();
+	}
+
+	return 0;
+}
+
+static void test_bucket_stats(struct rhashtable *ht)
+{
+	unsigned int err, total = 0, chain_len = 0;
+	struct rhashtable_iter hti;
+	struct rhash_head *pos;
+
+	err = rhashtable_walk_init(ht, &hti);
+	if (err) {
+		pr_warn("Test failed: allocation error");
+		return;
+	}
+
+	err = rhashtable_walk_start(&hti);
+	if (err && err != -EAGAIN) {
+		pr_warn("Test failed: iterator failed: %d\n", err);
+		return;
+	}
+
+	while ((pos = rhashtable_walk_next(&hti))) {
+		if (PTR_ERR(pos) == -EAGAIN) {
+			pr_info("Info: encountered resize\n");
+			chain_len++;
+			continue;
+		} else if (IS_ERR(pos)) {
+			pr_warn("Test failed: rhashtable_walk_next() error: %ld\n",
+				PTR_ERR(pos));
+			break;
+		}
+
+		total++;
+	}
+
+	rhashtable_walk_stop(&hti);
+	rhashtable_walk_exit(&hti);
+
+	pr_info("  Traversal complete: counted=%u, nelems=%u, entries=%d, table-jumps=%u\n",
+		total, atomic_read(&ht->nelems), entries, chain_len);
+
+	if (total != atomic_read(&ht->nelems) || total != entries)
+		pr_warn("Test failed: Total count mismatch ^^^");
+}
+
+static s64 __init test_rhashtable(struct rhashtable *ht)
+{
+	struct test_obj *obj;
+	int err;
+	unsigned int i, insert_fails = 0;
+	s64 start, end;
+
+	/*
+	 * Insertion Test:
+	 * Insert entries into table with all keys even numbers
+	 */
+	pr_info("  Adding %d keys\n", entries);
+	start = ktime_get_ns();
+	for (i = 0; i < entries; i++) {
+		struct test_obj *obj = &array[i];
+
+		obj->value = i * 2;
+
+		err = rhashtable_insert_fast(ht, &obj->node, test_rht_params);
+		if (err == -ENOMEM || err == -EBUSY) {
+			/* Mark failed inserts but continue */
+			obj->value = TEST_INSERT_FAIL;
+			insert_fails++;
+		} else if (err) {
+			return err;
+		}
+
+		cond_resched();
+	}
+
+	if (insert_fails)
+		pr_info("  %u insertions failed due to memory pressure\n",
+			insert_fails);
+
+	test_bucket_stats(ht);
+	rcu_read_lock();
+	test_rht_lookup(ht);
+	rcu_read_unlock();
+
+	test_bucket_stats(ht);
+
+	pr_info("  Deleting %d keys\n", entries);
+	for (i = 0; i < entries; i++) {
+		u32 key = i * 2;
+
+		if (array[i].value != TEST_INSERT_FAIL) {
+			obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
+			BUG_ON(!obj);
+
+			rhashtable_remove_fast(ht, &obj->node, test_rht_params);
+		}
+
+		cond_resched();
+	}
+
+	end = ktime_get_ns();
+	pr_info("  Duration of test: %lld ns\n", end - start);
+
+	return end - start;
+}
+
+static struct rhashtable ht;
+
+static int thread_lookup_test(struct thread_data *tdata)
+{
+	int i, err = 0;
+
+	for (i = 0; i < entries; i++) {
+		struct test_obj *obj;
+		int key = (tdata->id << 16) | i;
+
+		obj = rhashtable_lookup_fast(&ht, &key, test_rht_params);
+		if (obj && (tdata->objs[i].value == TEST_INSERT_FAIL)) {
+			pr_err("  found unexpected object %d\n", key);
+			err++;
+		} else if (!obj && (tdata->objs[i].value != TEST_INSERT_FAIL)) {
+			pr_err("  object %d not found!\n", key);
+			err++;
+		} else if (obj && (obj->value != key)) {
+			pr_err("  wrong object returned (got %d, expected %d)\n",
+			       obj->value, key);
+			err++;
+		}
+	}
+	return err;
+}
+
+static int threadfunc(void *data)
+{
+	int i, step, err = 0, insert_fails = 0;
+	struct thread_data *tdata = data;
+
+	up(&prestart_sem);
+	if (down_interruptible(&startup_sem))
+		pr_err("  thread[%d]: down_interruptible failed\n", tdata->id);
+
+	for (i = 0; i < entries; i++) {
+		tdata->objs[i].value = (tdata->id << 16) | i;
+		err = rhashtable_insert_fast(&ht, &tdata->objs[i].node,
+		                             test_rht_params);
+		if (err == -ENOMEM || err == -EBUSY) {
+			tdata->objs[i].value = TEST_INSERT_FAIL;
+			insert_fails++;
+		} else if (err) {
+			pr_err("  thread[%d]: rhashtable_insert_fast failed\n",
+			       tdata->id);
+			goto out;
+		}
+	}
+	if (insert_fails)
+		pr_info("  thread[%d]: %d insert failures\n",
+		        tdata->id, insert_fails);
+
+	err = thread_lookup_test(tdata);
+	if (err) {
+		pr_err("  thread[%d]: rhashtable_lookup_test failed\n",
+		       tdata->id);
+		goto out;
+	}
+
+	for (step = 10; step > 0; step--) {
+		for (i = 0; i < entries; i += step) {
+			if (tdata->objs[i].value == TEST_INSERT_FAIL)
+				continue;
+			err = rhashtable_remove_fast(&ht, &tdata->objs[i].node,
+			                             test_rht_params);
+			if (err) {
+				pr_err("  thread[%d]: rhashtable_remove_fast failed\n",
+				       tdata->id);
+				goto out;
+			}
+			tdata->objs[i].value = TEST_INSERT_FAIL;
+		}
+		err = thread_lookup_test(tdata);
+		if (err) {
+			pr_err("  thread[%d]: rhashtable_lookup_test (2) failed\n",
+			       tdata->id);
+			goto out;
+		}
+	}
+out:
+	while (!kthread_should_stop()) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule();
+	}
+	return err;
+}
+
+static int __init test_rht_init(void)
+{
+	int i, err, started_threads = 0, failed_threads = 0;
+	u64 total_time = 0;
+	struct thread_data *tdata;
+	struct test_obj *objs;
+
+	entries = min(entries, MAX_ENTRIES);
+
+	test_rht_params.automatic_shrinking = shrinking;
+	test_rht_params.max_size = max_size;
+	test_rht_params.nelem_hint = size;
+
+	pr_info("Running rhashtable test nelem=%d, max_size=%d, shrinking=%d\n",
+		size, max_size, shrinking);
+
+	for (i = 0; i < runs; i++) {
+		s64 time;
+
+		pr_info("Test %02d:\n", i);
+		memset(&array, 0, sizeof(array));
+		err = rhashtable_init(&ht, &test_rht_params);
+		if (err < 0) {
+			pr_warn("Test failed: Unable to initialize hashtable: %d\n",
+				err);
+			continue;
+		}
+
+		time = test_rhashtable(&ht);
+		rhashtable_destroy(&ht);
+		if (time < 0) {
+			pr_warn("Test failed: return code %lld\n", time);
+			return -EINVAL;
+		}
+
+		total_time += time;
+	}
+
+	do_div(total_time, runs);
+	pr_info("Average test time: %llu\n", total_time);
+
+	if (!tcount)
+		return 0;
+
+	pr_info("Testing concurrent rhashtable access from %d threads\n",
+	        tcount);
+	sema_init(&prestart_sem, 1 - tcount);
+	tdata = vzalloc(tcount * sizeof(struct thread_data));
+	if (!tdata)
+		return -ENOMEM;
+	objs  = vzalloc(tcount * entries * sizeof(struct test_obj));
+	if (!objs) {
+		vfree(tdata);
+		return -ENOMEM;
+	}
+
+	err = rhashtable_init(&ht, &test_rht_params);
+	if (err < 0) {
+		pr_warn("Test failed: Unable to initialize hashtable: %d\n",
+			err);
+		vfree(tdata);
+		vfree(objs);
+		return -EINVAL;
+	}
+	for (i = 0; i < tcount; i++) {
+		tdata[i].id = i;
+		tdata[i].objs = objs + i * entries;
+		tdata[i].task = kthread_run(threadfunc, &tdata[i],
+		                            "rhashtable_thrad[%d]", i);
+		if (IS_ERR(tdata[i].task))
+			pr_err(" kthread_run failed for thread %d\n", i);
+		else
+			started_threads++;
+	}
+	if (down_interruptible(&prestart_sem))
+		pr_err("  down interruptible failed\n");
+	for (i = 0; i < tcount; i++)
+		up(&startup_sem);
+	for (i = 0; i < tcount; i++) {
+		if (IS_ERR(tdata[i].task))
+			continue;
+		if ((err = kthread_stop(tdata[i].task))) {
+			pr_warn("Test failed: thread %d returned: %d\n",
+			        i, err);
+			failed_threads++;
+		}
+	}
+	pr_info("Started %d threads, %d failed\n",
+	        started_threads, failed_threads);
+	rhashtable_destroy(&ht);
+	vfree(tdata);
+	vfree(objs);
+	return 0;
+}
+
+static void __exit test_rht_exit(void)
+{
+}
+
+module_init(test_rht_init);
+module_exit(test_rht_exit);
+
+MODULE_LICENSE("GPL v2");