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