1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/*
* 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 struct rhashtable ht;
static int __init test_rht_init(void)
{
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, ¶ms);
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");
|
