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