1 files changed, 227 insertions, 0 deletions

diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
new file mode 100644
index 000000000000..1dfeba73fc74
--- /dev/null
+++ b/lib/test_rhashtable.c
@@ -0,0 +1,227 @@
+/*
+ * Resizable, Scalable, Concurrent Hash Table
+ *
+ * Copyright (c) 2014 Thomas Graf <tgraf@suug.ch>
+ * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net>
+ *
+ * Based on the following paper:
+ * https://www.usenix.org/legacy/event/atc11/tech/final_files/Triplett.pdf
+ *
+ * Code partially derived from nft_hash
+ *
+ * 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/module.h>
+#include <linux/rcupdate.h>
+#include <linux/rhashtable.h>
+#include <linux/slab.h>
+
+
+#define TEST_HT_SIZE    8
+#define TEST_ENTRIES    2048
+#define TEST_PTR        ((void *) 0xdeadbeef)
+#define TEST_NEXPANDS   4
+
+struct test_obj {
+        void                    *ptr;
+        int                     value;
+        struct rhash_head       node;
+};
+
+static int __init test_rht_lookup(struct rhashtable *ht)
+{
+        unsigned int i;
+
+        for (i = 0; i < TEST_ENTRIES * 2; i++) {
+                struct test_obj *obj;
+                bool expected = !(i % 2);
+                u32 key = i;
+
+                obj = rhashtable_lookup(ht, &key);
+
+                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->ptr != TEST_PTR || obj->value != i) {
+                                pr_warn("Test failed: Lookup value mismatch %p!=%p, %u!=%u\n",
+                                        obj->ptr, TEST_PTR, obj->value, i);
+                                return -EINVAL;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+static void test_bucket_stats(struct rhashtable *ht, bool quiet)
+{
+        unsigned int cnt, rcu_cnt, i, total = 0;
+        struct rhash_head *pos;
+        struct test_obj *obj;
+        struct bucket_table *tbl;
+
+        tbl = rht_dereference_rcu(ht->tbl, ht);
+        for (i = 0; i < tbl->size; i++) {
+                rcu_cnt = cnt = 0;
+
+                if (!quiet)
+                        pr_info(" [%#4x/%zu]", i, tbl->size);
+
+                rht_for_each_entry_rcu(obj, pos, tbl, i, node) {
+                        cnt++;
+                        total++;
+                        if (!quiet)
+                                pr_cont(" [%p],", obj);
+                }
+
+                rht_for_each_entry_rcu(obj, pos, tbl, i, node)
+                        rcu_cnt++;
+
+                if (rcu_cnt != cnt)
+                        pr_warn("Test failed: Chain count mismach %d != %d",
+                                cnt, rcu_cnt);
+
+                if (!quiet)
+                        pr_cont("\n  [%#x] first element: %p, chain length: %u\n",
+                                i, tbl->buckets[i], cnt);
+        }
+
+        pr_info("  Traversal complete: counted=%u, nelems=%u, entries=%d\n",
+                total, atomic_read(&ht->nelems), TEST_ENTRIES);
+
+        if (total != atomic_read(&ht->nelems) || total != TEST_ENTRIES)
+                pr_warn("Test failed: Total count mismatch ^^^");
+}
+
+static int __init test_rhashtable(struct rhashtable *ht)
+{
+        struct bucket_table *tbl;
+        struct test_obj *obj;
+        struct rhash_head *pos, *next;
+        int err;
+        unsigned int i;
+
+        /*
+         * Insertion Test:
+         * Insert TEST_ENTRIES into table with all keys even numbers
+         */
+        pr_info("  Adding %d keys\n", TEST_ENTRIES);
+        for (i = 0; i < TEST_ENTRIES; i++) {
+                struct test_obj *obj;
+
+                obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+                if (!obj) {
+                        err = -ENOMEM;
+                        goto error;
+                }
+
+                obj->ptr = TEST_PTR;
+                obj->value = i * 2;
+
+                rhashtable_insert(ht, &obj->node);
+        }
+
+        rcu_read_lock();
+        test_bucket_stats(ht, true);
+        test_rht_lookup(ht);
+        rcu_read_unlock();
+
+        for (i = 0; i < TEST_NEXPANDS; i++) {
+                pr_info("  Table expansion iteration %u...\n", i);
+                mutex_lock(&ht->mutex);
+                rhashtable_expand(ht);
+                mutex_unlock(&ht->mutex);
+
+                rcu_read_lock();
+                pr_info("  Verifying lookups...\n");
+                test_rht_lookup(ht);
+                rcu_read_unlock();
+        }
+
+        for (i = 0; i < TEST_NEXPANDS; i++) {
+                pr_info("  Table shrinkage iteration %u...\n", i);
+                mutex_lock(&ht->mutex);
+                rhashtable_shrink(ht);
+                mutex_unlock(&ht->mutex);
+
+                rcu_read_lock();
+                pr_info("  Verifying lookups...\n");
+                test_rht_lookup(ht);
+                rcu_read_unlock();
+        }
+
+        rcu_read_lock();
+        test_bucket_stats(ht, true);
+        rcu_read_unlock();
+
+        pr_info("  Deleting %d keys\n", TEST_ENTRIES);
+        for (i = 0; i < TEST_ENTRIES; i++) {
+                u32 key = i * 2;
+
+                obj = rhashtable_lookup(ht, &key);
+                BUG_ON(!obj);
+
+                rhashtable_remove(ht, &obj->node);
+                kfree(obj);
+        }
+
+        return 0;
+
+error:
+        tbl = rht_dereference_rcu(ht->tbl, ht);
+        for (i = 0; i < tbl->size; i++)
+                rht_for_each_entry_safe(obj, pos, next, tbl, i, node)
+                        kfree(obj);
+
+        return err;
+}
+
+static int __init test_rht_init(void)
+{
+        struct rhashtable ht;
+        struct rhashtable_params params = {
+                .nelem_hint = TEST_HT_SIZE,
+                .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),
+                .grow_decision = rht_grow_above_75,
+                .shrink_decision = rht_shrink_below_30,
+        };
+        int err;
+
+        pr_info("Running resizable hashtable tests...\n");
+
+        err = rhashtable_init(&ht, &params);
+        if (err < 0) {
+                pr_warn("Test failed: Unable to initialize hashtable: %d\n",
+                        err);
+                return err;
+        }
+
+        err = test_rhashtable(&ht);
+
+        rhashtable_destroy(&ht);
+
+        return err;
+}
+
+module_init(test_rht_init);
+
+MODULE_LICENSE("GPL v2");