1 /*
2  * Copyright (C) 2013-2021 Canonical, Ltd.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17  *
18  * This code is a complete clean re-write of the stress tool by
19  * Colin Ian King <colin.king@canonical.com> and attempts to be
20  * backwardly compatible with the stress tool by Amos Waterland
21  * <apw@rossby.metr.ou.edu> but has more stress tests and more
22  * functionality.
23  *
24  */
25 #include "stress-ng.h"
26 
27 static const stress_help_t help[] = {
28 	{ NULL,	"hsearch N",	  "start N workers that exercise a hash table search" },
29 	{ NULL,	"hsearch-ops N",  "stop after N hash search bogo operations" },
30 	{ NULL,	"hsearch-size N", "number of integers to insert into hash table" },
31 	{ NULL,	NULL,		  NULL }
32 };
33 
34 /*
35  *  stress_set_hsearch_size()
36  *      set hsearch size from given option string
37  */
stress_set_hsearch_size(const char * opt)38 static int stress_set_hsearch_size(const char *opt)
39 {
40 	uint64_t hsearch_size;
41 
42 	hsearch_size = stress_get_uint64(opt);
43 	stress_check_range("hsearch-size", hsearch_size,
44 		MIN_TSEARCH_SIZE, MAX_TSEARCH_SIZE);
45 	return stress_set_setting("hsearch-size", TYPE_ID_UINT64, &hsearch_size);
46 }
47 
48 /*
49  *  stress_hsearch()
50  *	stress hsearch
51  */
stress_hsearch(const stress_args_t * args)52 static int stress_hsearch(const stress_args_t *args)
53 {
54 	uint64_t hsearch_size = DEFAULT_HSEARCH_SIZE;
55 	size_t i, max;
56 	int ret = EXIT_FAILURE;
57 	char **keys;
58 
59 	if (!stress_get_setting("hsearch-size", &hsearch_size)) {
60 		if (g_opt_flags & OPT_FLAGS_MAXIMIZE)
61 			hsearch_size = MAX_HSEARCH_SIZE;
62 		if (g_opt_flags & OPT_FLAGS_MINIMIZE)
63 			hsearch_size = MIN_HSEARCH_SIZE;
64 	}
65 
66 	max = (size_t)hsearch_size;
67 
68 	/* Make hash table with 25% slack */
69 	if (!hcreate(max + (max / 4))) {
70 		pr_fail("%s: hcreate of size %zd failed\n", args->name, max + (max / 4));
71 		return EXIT_FAILURE;
72 	}
73 
74 	keys = calloc(max, sizeof(*keys));
75 	if (!keys) {
76 		pr_err("%s: cannot allocate keys\n", args->name);
77 		goto free_hash;
78 	}
79 
80 	/* Populate hash, make it 100% full for worst performance */
81 	for (i = 0; i < max; i++) {
82 		char buffer[32];
83 		ENTRY e;
84 
85 		(void)snprintf(buffer, sizeof(buffer), "%zu", i);
86 		keys[i] = strdup(buffer);
87 		if (!keys[i]) {
88 			pr_err("%s: cannot allocate key\n", args->name);
89 			goto free_all;
90 		}
91 
92 		e.key = keys[i];
93 		e.data = (void *)i;
94 
95 		if (hsearch(e, ENTER) == NULL) {
96 			pr_err("%s: cannot allocate new hash item\n", args->name);
97 			goto free_all;
98 		}
99 	}
100 
101 	stress_set_proc_state(args->name, STRESS_STATE_RUN);
102 
103 	do {
104 		for (i = 0; keep_stressing_flag() && i < max; i++) {
105 			ENTRY e, *ep;
106 
107 			e.key = keys[i];
108 			e.data = NULL;	/* Keep Coverity quiet */
109 			ep = hsearch(e, FIND);
110 			if (g_opt_flags & OPT_FLAGS_VERIFY) {
111 				if (ep == NULL) {
112 					pr_fail("%s: cannot find key %s\n", args->name, keys[i]);
113 				} else {
114 					if (i != (size_t)ep->data) {
115 						pr_fail("%s: hash returned incorrect data %zd\n", args->name, i);
116 					}
117 				}
118 			}
119 		}
120 		inc_counter(args);
121 	} while (keep_stressing(args));
122 
123 	ret = EXIT_SUCCESS;
124 
125 free_all:
126 	stress_set_proc_state(args->name, STRESS_STATE_DEINIT);
127 
128 	/*
129 	 * The semantics to hdestroy are rather varied from
130 	 * system to system.  OpenBSD will free the keys,
131 	 * where as NetBSD provides traditional functionality
132 	 * that does not free them, plus hdestroy1 where
133 	 * one can provide a free'ing callback.  Linux
134 	 * currently does not destroy them.  It's a mess,
135 	 * so for now, don't free them and just let it
136 	 * leak, the exit() will clean up the heap for us
137 	 */
138 #if defined(__linux__)
139 	for (i = 0; i < max; i++)
140 		free(keys[i]);
141 #endif
142 	free(keys);
143 free_hash:
144 	stress_set_proc_state(args->name, STRESS_STATE_DEINIT);
145 	hdestroy();
146 
147 	return ret;
148 }
149 
150 static const stress_opt_set_func_t opt_set_funcs[] = {
151 	{ OPT_hsearch_size,	stress_set_hsearch_size },
152 	{ 0,			NULL }
153 };
154 
155 stressor_info_t stress_hsearch_info = {
156 	.stressor = stress_hsearch,
157 	.class = CLASS_CPU_CACHE | CLASS_CPU | CLASS_MEMORY,
158 	.opt_set_funcs = opt_set_funcs,
159 	.help = help
160 };
161