1 files changed, 281 insertions, 87 deletions

diff --git a/kernel/lib/test_rhashtable.c b/kernel/lib/test_rhashtable.c
index b2957540d..8c1ad1ced 100644
--- a/kernel/lib/test_rhashtable.c
+++ b/kernel/lib/test_rhashtable.c
@@ -1,14 +1,9 @@
 /*
  * 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.
@@ -21,25 +16,56 @@
 #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),
@@ -47,15 +73,21 @@ static const struct rhashtable_params test_rht_params = {
 	.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) {
@@ -66,140 +98,302 @@ static int __init test_rht_lookup(struct rhashtable *ht)
 				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)