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-rw-r--r--lib/test_rhashtable.c227
1 files changed, 227 insertions, 0 deletions
diff --git a/lib/test_rhashtable.c b/lib/test_rhashtable.c
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+/*
+ * 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");