// SPDX-License-Identifier: GPL-2.0-only /* * Resizable, Scalable, Concurrent Hash Table * * Copyright (c) 2014-2015 Thomas Graf <tgraf@suug.ch> * Copyright (c) 2008-2014 Patrick McHardy <kaber@trash.net> */ /************************************************************************** * 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/slab.h> #include <linux/sched.h> #include <linux/random.h> #include <linux/vmalloc.h> #include <linux/wait.h> #define MAX_ENTRIES 1000000 #define TEST_INSERT_FAIL INT_MAX static int parm_entries = 50000; module_param(parm_entries, int, 0); MODULE_PARM_DESC(parm_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 = 0; module_param(max_size, int, 0); MODULE_PARM_DESC(max_size, "Maximum table size (default: calculated)"); 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)"); static bool enomem_retry = false; module_param(enomem_retry, bool, 0); MODULE_PARM_DESC(enomem_retry, "Retry insert even if -ENOMEM was returned (default: off)"); struct test_obj_val { int id; int tid; }; struct test_obj { struct test_obj_val value; struct rhash_head node; }; struct test_obj_rhl { struct test_obj_val value; struct rhlist_head list_node; }; struct thread_data { unsigned int entries; int id; struct task_struct *task; struct test_obj *objs; }; static u32 my_hashfn(const void *data, u32 len, u32 seed) { const struct test_obj_rhl *obj = data; return (obj->value.id % 10); } static int my_cmpfn(struct rhashtable_compare_arg *arg, const void *obj) { const struct test_obj_rhl *test_obj = obj; const struct test_obj_val *val = arg->key; return test_obj->value.id - val->id; } static struct rhashtable_params test_rht_params = { .head_offset = offsetof(struct test_obj, node), .key_offset = offsetof(struct test_obj, value), .key_len = sizeof(struct test_obj_val), .hashfn = jhash, }; static struct rhashtable_params test_rht_params_dup = { .head_offset = offsetof(struct test_obj_rhl, list_node), .key_offset = offsetof(struct test_obj_rhl, value), .key_len = sizeof(struct test_obj_val), .hashfn = jhash, .obj_hashfn = my_hashfn, .obj_cmpfn = my_cmpfn, .nelem_hint = 128, .automatic_shrinking = false, }; static atomic_t startup_count; static DECLARE_WAIT_QUEUE_HEAD(startup_wait); static int insert_retry(struct rhashtable *ht, struct test_obj *obj, const struct rhashtable_params params) { int err, retries = -1, enomem_retries = 0; do { retries++; cond_resched(); err = rhashtable_insert_fast(ht, &obj->node, params); if (err == -ENOMEM && enomem_retry) { enomem_retries++; err = -EBUSY; } } while (err == -EBUSY); if (enomem_retries) pr_info(" %u insertions retried after -ENOMEM\n", enomem_retries); return err ? : retries; } static int __init test_rht_lookup(struct rhashtable *ht, struct test_obj *array, unsigned int entries) { unsigned int i; for (i = 0; i < entries; i++) { struct test_obj *obj; bool expected = !(i % 2); struct test_obj_val key = { .id = i, }; if (array[i / 2].value.id == 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.id); return -ENOENT; } else if (!expected && obj) { pr_warn("Test failed: Unexpected entry found for key %u\n", key.id); return -EEXIST; } else if (expected && obj) { if (obj->value.id != i) { pr_warn("Test failed: Lookup value mismatch %u!=%u\n", obj->value.id, i); return -EINVAL; } } cond_resched_rcu(); } return 0; } static void test_bucket_stats(struct rhashtable *ht, unsigned int entries) { unsigned int total = 0, chain_len = 0; struct rhashtable_iter hti; struct rhash_head *pos; rhashtable_walk_enter(ht, &hti); rhashtable_walk_start(&hti); 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 *array, unsigned int entries) { struct test_obj *obj; int err; unsigned int i, insert_retries = 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.id = i * 2; err = insert_retry(ht, obj, test_rht_params); if (err > 0) insert_retries += err; else if (err) return err; } if (insert_retries) pr_info(" %u insertions retried due to memory pressure\n", insert_retries); test_bucket_stats(ht, entries); rcu_read_lock(); test_rht_lookup(ht, array, entries); rcu_read_unlock(); test_bucket_stats(ht, entries); pr_info(" Deleting %d keys\n", entries); for (i = 0; i < entries; i++) { struct test_obj_val key = { .id = i * 2, }; if (array[i].value.id != 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 struct rhltable rhlt; static int __init test_rhltable(unsigned int entries) { struct test_obj_rhl *rhl_test_objects; unsigned long *obj_in_table; unsigned int i, j, k; int ret, err; if (entries == 0) entries = 1; rhl_test_objects = vzalloc(array_size(entries, sizeof(*rhl_test_objects))); if (!rhl_test_objects) return -ENOMEM; ret = -ENOMEM; obj_in_table = vzalloc(array_size(sizeof(unsigned long), BITS_TO_LONGS(entries))); if (!obj_in_table) goto out_free; err = rhltable_init(&rhlt, &test_rht_params); if (WARN_ON(err)) goto out_free; k = prandom_u32(); ret = 0; for (i = 0; i < entries; i++) { rhl_test_objects[i].value.id = k; err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); if (WARN(err, "error %d on element %d\n", err, i)) break; if (err == 0) set_bit(i, obj_in_table); } if (err) ret = err; pr_info("test %d add/delete pairs into rhlist\n", entries); for (i = 0; i < entries; i++) { struct rhlist_head *h, *pos; struct test_obj_rhl *obj; struct test_obj_val key = { .id = k, }; bool found; rcu_read_lock(); h = rhltable_lookup(&rhlt, &key, test_rht_params); if (WARN(!h, "key not found during iteration %d of %d", i, entries)) { rcu_read_unlock(); break; } if (i) { j = i - 1; rhl_for_each_entry_rcu(obj, pos, h, list_node) { if (WARN(pos == &rhl_test_objects[j].list_node, "old element found, should be gone")) break; } } cond_resched_rcu(); found = false; rhl_for_each_entry_rcu(obj, pos, h, list_node) { if (pos == &rhl_test_objects[i].list_node) { found = true; break; } } rcu_read_unlock(); if (WARN(!found, "element %d not found", i)) break; err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); WARN(err, "rhltable_remove: err %d for iteration %d\n", err, i); if (err == 0) clear_bit(i, obj_in_table); } if (ret == 0 && err) ret = err; for (i = 0; i < entries; i++) { WARN(test_bit(i, obj_in_table), "elem %d allegedly still present", i); err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); if (WARN(err, "error %d on element %d\n", err, i)) break; if (err == 0) set_bit(i, obj_in_table); } pr_info("test %d random rhlist add/delete operations\n", entries); for (j = 0; j < entries; j++) { u32 i = prandom_u32_max(entries); u32 prand = prandom_u32(); cond_resched(); if (prand == 0) prand = prandom_u32(); if (prand & 1) { prand >>= 1; continue; } err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); if (test_bit(i, obj_in_table)) { clear_bit(i, obj_in_table); if (WARN(err, "cannot remove element at slot %d", i)) continue; } else { if (WARN(err != -ENOENT, "removed non-existent element %d, error %d not %d", i, err, -ENOENT)) continue; } if (prand & 1) { prand >>= 1; continue; } err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); if (err == 0) { if (WARN(test_and_set_bit(i, obj_in_table), "succeeded to insert same object %d", i)) continue; } else { if (WARN(!test_bit(i, obj_in_table), "failed to insert object %d", i)) continue; } if (prand & 1) { prand >>= 1; continue; } i = prandom_u32_max(entries); if (test_bit(i, obj_in_table)) { err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); WARN(err, "cannot remove element at slot %d", i); if (err == 0) clear_bit(i, obj_in_table); } else { err = rhltable_insert(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); WARN(err, "failed to insert object %d", i); if (err == 0) set_bit(i, obj_in_table); } } for (i = 0; i < entries; i++) { cond_resched(); err = rhltable_remove(&rhlt, &rhl_test_objects[i].list_node, test_rht_params); if (test_bit(i, obj_in_table)) { if (WARN(err, "cannot remove element at slot %d", i)) continue; } else { if (WARN(err != -ENOENT, "removed non-existent element, error %d not %d", err, -ENOENT)) continue; } } rhltable_destroy(&rhlt); out_free: vfree(rhl_test_objects); vfree(obj_in_table); return ret; } static int __init test_rhashtable_max(struct test_obj *array, unsigned int entries) { unsigned int i, insert_retries = 0; int err; test_rht_params.max_size = roundup_pow_of_two(entries / 8); err = rhashtable_init(&ht, &test_rht_params); if (err) return err; for (i = 0; i < ht.max_elems; i++) { struct test_obj *obj = &array[i]; obj->value.id = i * 2; err = insert_retry(&ht, obj, test_rht_params); if (err > 0) insert_retries += err; else if (err) return err; } err = insert_retry(&ht, &array[ht.max_elems], test_rht_params); if (err == -E2BIG) { err = 0; } else { pr_info("insert element %u should have failed with %d, got %d\n", ht.max_elems, -E2BIG, err); if (err == 0) err = -1; } rhashtable_destroy(&ht); return err; } static unsigned int __init print_ht(struct rhltable *rhlt) { struct rhashtable *ht; const struct bucket_table *tbl; char buff[512] = ""; int offset = 0; unsigned int i, cnt = 0; ht = &rhlt->ht; /* Take the mutex to avoid RCU warning */ mutex_lock(&ht->mutex); tbl = rht_dereference(ht->tbl, ht); for (i = 0; i < tbl->size; i++) { struct rhash_head *pos, *next; struct test_obj_rhl *p; pos = rht_ptr_exclusive(tbl->buckets + i); next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL; if (!rht_is_a_nulls(pos)) { offset += sprintf(buff + offset, "\nbucket[%d] -> ", i); } while (!rht_is_a_nulls(pos)) { struct rhlist_head *list = container_of(pos, struct rhlist_head, rhead); offset += sprintf(buff + offset, "[["); do { pos = &list->rhead; list = rht_dereference(list->next, ht); p = rht_obj(ht, pos); offset += sprintf(buff + offset, " val %d (tid=%d)%s", p->value.id, p->value.tid, list? ", " : " "); cnt++; } while (list); pos = next, next = !rht_is_a_nulls(pos) ? rht_dereference(pos->next, ht) : NULL; offset += sprintf(buff + offset, "]]%s", !rht_is_a_nulls(pos) ? " -> " : ""); } } printk(KERN_ERR "\n---- ht: ----%s\n-------------\n", buff); mutex_unlock(&ht->mutex); return cnt; } static int __init test_insert_dup(struct test_obj_rhl *rhl_test_objects, int cnt, bool slow) { struct rhltable *rhlt; unsigned int i, ret; const char *key; int err = 0; rhlt = kmalloc(sizeof(*rhlt), GFP_KERNEL); if (WARN_ON(!rhlt)) return -EINVAL; err = rhltable_init(rhlt, &test_rht_params_dup); if (WARN_ON(err)) { kfree(rhlt); return err; } for (i = 0; i < cnt; i++) { rhl_test_objects[i].value.tid = i; key = rht_obj(&rhlt->ht, &rhl_test_objects[i].list_node.rhead); key += test_rht_params_dup.key_offset; if (slow) { err = PTR_ERR(rhashtable_insert_slow(&rhlt->ht, key, &rhl_test_objects[i].list_node.rhead)); if (err == -EAGAIN) err = 0; } else err = rhltable_insert(rhlt, &rhl_test_objects[i].list_node, test_rht_params_dup); if (WARN(err, "error %d on element %d/%d (%s)\n", err, i, cnt, slow? "slow" : "fast")) goto skip_print; } ret = print_ht(rhlt); WARN(ret != cnt, "missing rhltable elements (%d != %d, %s)\n", ret, cnt, slow? "slow" : "fast"); skip_print: rhltable_destroy(rhlt); kfree(rhlt); return 0; } static int __init test_insert_duplicates_run(void) { struct test_obj_rhl rhl_test_objects[3] = {}; pr_info("test inserting duplicates\n"); /* two different values that map to same bucket */ rhl_test_objects[0].value.id = 1; rhl_test_objects[1].value.id = 21; /* and another duplicate with same as [0] value * which will be second on the bucket list */ rhl_test_objects[2].value.id = rhl_test_objects[0].value.id; test_insert_dup(rhl_test_objects, 2, false); test_insert_dup(rhl_test_objects, 3, false); test_insert_dup(rhl_test_objects, 2, true); test_insert_dup(rhl_test_objects, 3, true); return 0; } static int thread_lookup_test(struct thread_data *tdata) { unsigned int entries = tdata->entries; int i, err = 0; for (i = 0; i < entries; i++) { struct test_obj *obj; struct test_obj_val key = { .id = i, .tid = tdata->id, }; obj = rhashtable_lookup_fast(&ht, &key, test_rht_params); if (obj && (tdata->objs[i].value.id == TEST_INSERT_FAIL)) { pr_err(" found unexpected object %d-%d\n", key.tid, key.id); err++; } else if (!obj && (tdata->objs[i].value.id != TEST_INSERT_FAIL)) { pr_err(" object %d-%d not found!\n", key.tid, key.id); err++; } else if (obj && memcmp(&obj->value, &key, sizeof(key))) { pr_err(" wrong object returned (got %d-%d, expected %d-%d)\n", obj->value.tid, obj->value.id, key.tid, key.id); err++; } cond_resched(); } return err; } static int threadfunc(void *data) { int i, step, err = 0, insert_retries = 0; struct thread_data *tdata = data; if (atomic_dec_and_test(&startup_count)) wake_up(&startup_wait); if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == -1)) { pr_err(" thread[%d]: interrupted\n", tdata->id); goto out; } for (i = 0; i < tdata->entries; i++) { tdata->objs[i].value.id = i; tdata->objs[i].value.tid = tdata->id; err = insert_retry(&ht, &tdata->objs[i], test_rht_params); if (err > 0) { insert_retries += err; } else if (err) { pr_err(" thread[%d]: rhashtable_insert_fast failed\n", tdata->id); goto out; } } if (insert_retries) pr_info(" thread[%d]: %u insertions retried due to memory pressure\n", tdata->id, insert_retries); 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 < tdata->entries; i += step) { if (tdata->objs[i].value.id == 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.id = TEST_INSERT_FAIL; cond_resched(); } 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) { unsigned int entries; int i, err, started_threads = 0, failed_threads = 0; u64 total_time = 0; struct thread_data *tdata; struct test_obj *objs; if (parm_entries < 0) parm_entries = 1; entries = min(parm_entries, MAX_ENTRIES); test_rht_params.automatic_shrinking = shrinking; test_rht_params.max_size = max_size ? : roundup_pow_of_two(entries); test_rht_params.nelem_hint = size; objs = vzalloc(array_size(sizeof(struct test_obj), test_rht_params.max_size + 1)); if (!objs) return -ENOMEM; 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(objs, 0, test_rht_params.max_size * sizeof(struct test_obj)); 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, objs, entries); rhashtable_destroy(&ht); if (time < 0) { vfree(objs); pr_warn("Test failed: return code %lld\n", time); return -EINVAL; } total_time += time; } pr_info("test if its possible to exceed max_size %d: %s\n", test_rht_params.max_size, test_rhashtable_max(objs, entries) == 0 ? "no, ok" : "YES, failed"); vfree(objs); do_div(total_time, runs); pr_info("Average test time: %llu\n", total_time); test_insert_duplicates_run(); if (!tcount) return 0; pr_info("Testing concurrent rhashtable access from %d threads\n", tcount); atomic_set(&startup_count, tcount); tdata = vzalloc(array_size(tcount, sizeof(struct thread_data))); if (!tdata) return -ENOMEM; objs = vzalloc(array3_size(sizeof(struct test_obj), tcount, entries)); if (!objs) { vfree(tdata); return -ENOMEM; } test_rht_params.max_size = max_size ? : roundup_pow_of_two(tcount * entries); 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].entries = entries; 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); atomic_dec(&startup_count); } else { started_threads++; } } if (wait_event_interruptible(startup_wait, atomic_read(&startup_count) == 0)) pr_err(" wait_event interruptible failed\n"); /* count is 0 now, set it to -1 and wake up all threads together */ atomic_dec(&startup_count); wake_up_all(&startup_wait); 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++; } } rhashtable_destroy(&ht); vfree(tdata); vfree(objs); /* * rhltable_remove is very expensive, default values can cause test * to run for 2 minutes or more, use a smaller number instead. */ err = test_rhltable(entries / 16); pr_info("Started %d threads, %d failed, rhltable test returns %d\n", started_threads, failed_threads, err); return 0; } static void __exit test_rht_exit(void) { } module_init(test_rht_init); module_exit(test_rht_exit); MODULE_LICENSE("GPL v2");