summaryrefslogtreecommitdiff
path: root/t/helper/test-lazy-init-name-hash.c
blob: cd1b4c9736ef2c658dd3467506cbe5c1612cd4d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
#include "test-tool.h"
#include "cache.h"
#include "parse-options.h"
 
static int single;
static int multi;
static int count = 1;
static int dump;
static int perf;
static int analyze;
static int analyze_step;
 
/*
 * Dump the contents of the "dir" and "name" hash tables to stdout.
 * If you sort the result, you can compare it with the other type
 * mode and verify that both single and multi produce the same set.
 */
static void dump_run(void)
{
	struct hashmap_iter iter_dir;
	struct hashmap_iter iter_cache;
 
	/* Stolen from name-hash.c */
	struct dir_entry {
		struct hashmap_entry ent;
		struct dir_entry *parent;
		int nr;
		unsigned int namelen;
		char name[FLEX_ARRAY];
	};
 
	struct dir_entry *dir;
	struct cache_entry *ce;
 
	read_cache();
	if (single) {
		test_lazy_init_name_hash(&the_index, 0);
	} else {
		int nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
		if (!nr_threads_used)
			die("non-threaded code path used");
	}
 
	hashmap_for_each_entry(&the_index.dir_hash, &iter_dir, dir,
				ent /* member name */)
		printf("dir %08x %7d %s\n", dir->ent.hash, dir->nr, dir->name);
 
	hashmap_for_each_entry(&the_index.name_hash, &iter_cache, ce,
				ent /* member name */)
		printf("name %08x %s\n", ce->ent.hash, ce->name);
 
	discard_cache();
}
 
/*
 * Run the single or multi threaded version "count" times and
 * report on the time taken.
 */
static uint64_t time_runs(int try_threaded)
{
	uint64_t t0, t1, t2;
	uint64_t sum = 0;
	uint64_t avg;
	int nr_threads_used;
	int i;
 
	for (i = 0; i < count; i++) {
		t0 = getnanotime();
		read_cache();
		t1 = getnanotime();
		nr_threads_used = test_lazy_init_name_hash(&the_index, try_threaded);
		t2 = getnanotime();
 
		sum += (t2 - t1);
 
		if (try_threaded && !nr_threads_used)
			die("non-threaded code path used");
 
		if (nr_threads_used)
			printf("%f %f %d multi %d\n",
				   ((double)(t1 - t0))/1000000000,
				   ((double)(t2 - t1))/1000000000,
				   the_index.cache_nr,
				   nr_threads_used);
		else
			printf("%f %f %d single\n",
				   ((double)(t1 - t0))/1000000000,
				   ((double)(t2 - t1))/1000000000,
				   the_index.cache_nr);
		fflush(stdout);
 
		discard_cache();
	}
 
	avg = sum / count;
	if (count > 1)
		printf("avg %f %s\n",
			   (double)avg/1000000000,
			   (try_threaded) ? "multi" : "single");
 
	return avg;
}
 
/*
 * Try a series of runs varying the "istate->cache_nr" and
 * try to find a good value for the multi-threaded criteria.
 */
static void analyze_run(void)
{
	uint64_t t1s, t1m, t2s, t2m;
	int cache_nr_limit;
	int nr_threads_used = 0;
	int i;
	int nr;
 
	read_cache();
	cache_nr_limit = the_index.cache_nr;
	discard_cache();
 
	nr = analyze;
	while (1) {
		uint64_t sum_single = 0;
		uint64_t sum_multi = 0;
		uint64_t avg_single;
		uint64_t avg_multi;
 
		if (nr > cache_nr_limit)
			nr = cache_nr_limit;
 
		for (i = 0; i < count; i++) {
			read_cache();
			the_index.cache_nr = nr; /* cheap truncate of index */
			t1s = getnanotime();
			test_lazy_init_name_hash(&the_index, 0);
			t2s = getnanotime();
			sum_single += (t2s - t1s);
			the_index.cache_nr = cache_nr_limit;
			discard_cache();
 
			read_cache();
			the_index.cache_nr = nr; /* cheap truncate of index */
			t1m = getnanotime();
			nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
			t2m = getnanotime();
			sum_multi += (t2m - t1m);
			the_index.cache_nr = cache_nr_limit;
			discard_cache();
 
			if (!nr_threads_used)
				printf("    [size %8d] [single %f]   non-threaded code path used\n",
					   nr, ((double)(t2s - t1s))/1000000000);
			else
				printf("    [size %8d] [single %f] %c [multi %f %d]\n",
					   nr,
					   ((double)(t2s - t1s))/1000000000,
					   (((t2s - t1s) < (t2m - t1m)) ? '<' : '>'),
					   ((double)(t2m - t1m))/1000000000,
					   nr_threads_used);
			fflush(stdout);
		}
		if (count > 1) {
			avg_single = sum_single / count;
			avg_multi = sum_multi / count;
			if (!nr_threads_used)
				printf("avg [size %8d] [single %f]\n",
					   nr,
					   (double)avg_single/1000000000);
			else
				printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
					   nr,
					   (double)avg_single/1000000000,
					   (avg_single < avg_multi ? '<' : '>'),
					   (double)avg_multi/1000000000,
					   nr_threads_used);
			fflush(stdout);
		}
 
		if (nr >= cache_nr_limit)
			return;
		nr += analyze_step;
	}
}
 
int cmd__lazy_init_name_hash(int argc, const char **argv)
{
	const char *usage[] = {
		"test-tool lazy-init-name-hash -d (-s | -m)",
		"test-tool lazy-init-name-hash -p [-c c]",
		"test-tool lazy-init-name-hash -a a [--step s] [-c c]",
		"test-tool lazy-init-name-hash (-s | -m) [-c c]",
		"test-tool lazy-init-name-hash -s -m [-c c]",
		NULL
	};
	struct option options[] = {
		OPT_BOOL('s', "single", &single, "run single-threaded code"),
		OPT_BOOL('m', "multi", &multi, "run multi-threaded code"),
		OPT_INTEGER('c', "count", &count, "number of passes"),
		OPT_BOOL('d', "dump", &dump, "dump hash tables"),
		OPT_BOOL('p', "perf", &perf, "compare single vs multi"),
		OPT_INTEGER('a', "analyze", &analyze, "analyze different multi sizes"),
		OPT_INTEGER(0, "step", &analyze_step, "analyze step factor"),
		OPT_END(),
	};
	const char *prefix;
	uint64_t avg_single, avg_multi;
 
	prefix = setup_git_directory();
 
	argc = parse_options(argc, argv, prefix, options, usage, 0);
 
	/*
	 * istate->dir_hash is only created when ignore_case is set.
	 */
	ignore_case = 1;
 
	if (dump) {
		if (perf || analyze > 0)
			die("cannot combine dump, perf, or analyze");
		if (count > 1)
			die("count not valid with dump");
		if (single && multi)
			die("cannot use both single and multi with dump");
		if (!single && !multi)
			die("dump requires either single or multi");
		dump_run();
		return 0;
	}
 
	if (perf) {
		if (analyze > 0)
			die("cannot combine dump, perf, or analyze");
		if (single || multi)
			die("cannot use single or multi with perf");
		avg_single = time_runs(0);
		avg_multi = time_runs(1);
		if (avg_multi > avg_single)
			die("multi is slower");
		return 0;
	}
 
	if (analyze) {
		if (analyze < 500)
			die("analyze must be at least 500");
		if (!analyze_step)
			analyze_step = analyze;
		if (single || multi)
			die("cannot use single or multi with analyze");
		analyze_run();
		return 0;
	}
 
	if (!single && !multi)
		die("require either -s or -m or both");
 
	if (single)
		time_runs(0);
	if (multi)
		time_runs(1);
 
	return 0;
}