/*
* Resizable, Scalable, Concurrent Hash Table
*
- * Copyright (c) 2014 Thomas Graf <tgraf@suug.ch>
+ * Copyright (c) 2014-2015 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.
#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)");
-#define TEST_HT_SIZE 8
-#define TEST_ENTRIES 2048
-#define TEST_PTR ((void *) 0xdeadbeef)
-#define TEST_NEXPANDS 4
+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 {
- void *ptr;
int value;
struct rhash_head node;
};
-static const struct rhashtable_params test_rht_params = {
- .nelem_hint = TEST_HT_SIZE,
+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),
.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 < TEST_ENTRIES * 2; 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) {
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);
+ 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, bool quiet)
+static void test_bucket_stats(struct rhashtable *ht)
{
- unsigned int cnt, rcu_cnt, i, total = 0;
+ unsigned int err, total = 0, chain_len = 0;
+ struct rhashtable_iter hti;
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;
+ err = rhashtable_walk_init(ht, &hti);
+ if (err) {
+ pr_warn("Test failed: allocation error");
+ return;
+ }
- if (!quiet)
- pr_info(" [%#4x/%u]", i, tbl->size);
+ err = rhashtable_walk_start(&hti);
+ if (err && err != -EAGAIN) {
+ pr_warn("Test failed: iterator failed: %d\n", err);
+ return;
+ }
- rht_for_each_entry_rcu(obj, pos, tbl, i, node) {
- cnt++;
- total++;
- if (!quiet)
- pr_cont(" [%p],", obj);
+ 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;
}
- 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);
+ total++;
}
- pr_info(" Traversal complete: counted=%u, nelems=%u, entries=%d\n",
- total, atomic_read(&ht->nelems), TEST_ENTRIES);
+ rhashtable_walk_stop(&hti);
+ rhashtable_walk_exit(&hti);
- if (total != atomic_read(&ht->nelems) || total != TEST_ENTRIES)
+ 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 int __init test_rhashtable(struct rhashtable *ht)
+static s64 __init test_rhashtable(struct rhashtable *ht)
{
- struct bucket_table *tbl;
struct test_obj *obj;
- struct rhash_head *pos, *next;
int err;
- unsigned int i;
+ unsigned int i, insert_fails = 0;
+ s64 start, end;
/*
* Insertion Test:
- * Insert TEST_ENTRIES into table with all keys even numbers
+ * Insert 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;
- }
+ pr_info(" Adding %d keys\n", entries);
+ start = ktime_get_ns();
+ for (i = 0; i < entries; i++) {
+ struct test_obj *obj = &array[i];
- obj->ptr = TEST_PTR;
obj->value = i * 2;
err = rhashtable_insert_fast(ht, &obj->node, test_rht_params);
- if (err) {
- kfree(obj);
- goto error;
+ 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_bucket_stats(ht, true);
test_rht_lookup(ht);
rcu_read_unlock();
- rcu_read_lock();
- test_bucket_stats(ht, true);
- rcu_read_unlock();
+ test_bucket_stats(ht);
- pr_info(" Deleting %d keys\n", TEST_ENTRIES);
- for (i = 0; i < TEST_ENTRIES; i++) {
+ pr_info(" Deleting %d keys\n", entries);
+ for (i = 0; i < entries; i++) {
u32 key = i * 2;
- obj = rhashtable_lookup_fast(ht, &key, test_rht_params);
- BUG_ON(!obj);
+ 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);
+ }
- rhashtable_remove_fast(ht, &obj->node, test_rht_params);
- kfree(obj);
+ cond_resched();
}
- return 0;
+ end = ktime_get_ns();
+ pr_info(" Duration of test: %lld ns\n", end - start);
+
+ return end - start;
+}
-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);
+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 struct rhashtable ht;
+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 err;
+ 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;
+ }
- pr_info("Running resizable hashtable tests...\n");
+ 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);
- return err;
+ vfree(tdata);
+ vfree(objs);
+ return -EINVAL;
}
-
- err = test_rhashtable(&ht);
-
+ 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);
-
- return err;
+ vfree(tdata);
+ vfree(objs);
+ return 0;
}
static void __exit test_rht_exit(void)
Code Review / kvmfornfv.git / blobdiff