/* * Resizable, Scalable, Concurrent Hash Table * * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch> * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> * * 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/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)"); 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 {	int			value;	struct rhash_head	node;}; 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),	.hashfn = jhash,	.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 < 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) {			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->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){	unsigned int err, total = 0, chain_len = 0;	struct rhashtable_iter hti;	struct rhash_head *pos; 	err = rhashtable_walk_init(ht, &hti);	if (err) {		pr_warn("Test failed: allocation error");		return;	} 	err = rhashtable_walk_start(&hti);	if (err && err != -EAGAIN) {		pr_warn("Test failed: iterator failed: %d\n", err);		return;	} 	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;		} 		total++;	} 	rhashtable_walk_stop(&hti);	rhashtable_walk_exit(&hti); 	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 s64 __init test_rhashtable(struct rhashtable *ht){	struct test_obj *obj;	int err;	unsigned int i, insert_fails = 0;	s64 start, end; 	/*	 * Insertion Test:	 * Insert entries into table with all keys even numbers	 */	pr_info("  Adding %d keys\n", entries);	start = ktime_get_ns();	for (i = 0; i < entries; i++) {		struct test_obj *obj = &array[i]; 		obj->value = i * 2; 		err = rhashtable_insert_fast(ht, &obj->node, test_rht_params);		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_rht_lookup(ht);	rcu_read_unlock(); 	test_bucket_stats(ht); 	pr_info("  Deleting %d keys\n", entries);	for (i = 0; i < entries; i++) {		u32 key = i * 2; 		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);		} 		cond_resched();	} 	end = ktime_get_ns();	pr_info("  Duration of test: %lld ns\n", end - start); 	return end - start;} 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 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 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;		} 		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);		vfree(tdata);		vfree(objs);		return -EINVAL;	}	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);	vfree(tdata);	vfree(objs);	return 0;} static void __exit test_rht_exit(void){} module_init(test_rht_init);module_exit(test_rht_exit); MODULE_LICENSE("GPL v2");