Git 2.18.4
[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         dir = hashmap_iter_first(&the_index.dir_hash, &iter_dir);
45         while (dir) {
46                 printf("dir %08x %7d %s\n", dir->ent.hash, dir->nr, dir->name);
47                 dir = hashmap_iter_next(&iter_dir);
48         }
49
50         ce = hashmap_iter_first(&the_index.name_hash, &iter_cache);
51         while (ce) {
52                 printf("name %08x %s\n", ce->ent.hash, ce->name);
53                 ce = hashmap_iter_next(&iter_cache);
54         }
55
56         discard_cache();
57 }
58
59 /*
60  * Run the single or multi threaded version "count" times and
61  * report on the time taken.
62  */
63 static uint64_t time_runs(int try_threaded)
64 {
65         uint64_t t0, t1, t2;
66         uint64_t sum = 0;
67         uint64_t avg;
68         int nr_threads_used;
69         int i;
70
71         for (i = 0; i < count; i++) {
72                 t0 = getnanotime();
73                 read_cache();
74                 t1 = getnanotime();
75                 nr_threads_used = test_lazy_init_name_hash(&the_index, try_threaded);
76                 t2 = getnanotime();
77
78                 sum += (t2 - t1);
79
80                 if (try_threaded && !nr_threads_used)
81                         die("non-threaded code path used");
82
83                 if (nr_threads_used)
84                         printf("%f %f %d multi %d\n",
85                                    ((double)(t1 - t0))/1000000000,
86                                    ((double)(t2 - t1))/1000000000,
87                                    the_index.cache_nr,
88                                    nr_threads_used);
89                 else
90                         printf("%f %f %d single\n",
91                                    ((double)(t1 - t0))/1000000000,
92                                    ((double)(t2 - t1))/1000000000,
93                                    the_index.cache_nr);
94                 fflush(stdout);
95
96                 discard_cache();
97         }
98
99         avg = sum / count;
100         if (count > 1)
101                 printf("avg %f %s\n",
102                            (double)avg/1000000000,
103                            (try_threaded) ? "multi" : "single");
104
105         return avg;
106 }
107
108 /*
109  * Try a series of runs varying the "istate->cache_nr" and
110  * try to find a good value for the multi-threaded criteria.
111  */
112 static void analyze_run(void)
113 {
114         uint64_t t1s, t1m, t2s, t2m;
115         int cache_nr_limit;
116         int nr_threads_used = 0;
117         int i;
118         int nr;
119
120         read_cache();
121         cache_nr_limit = the_index.cache_nr;
122         discard_cache();
123
124         nr = analyze;
125         while (1) {
126                 uint64_t sum_single = 0;
127                 uint64_t sum_multi = 0;
128                 uint64_t avg_single;
129                 uint64_t avg_multi;
130
131                 if (nr > cache_nr_limit)
132                         nr = cache_nr_limit;
133
134                 for (i = 0; i < count; i++) {
135                         read_cache();
136                         the_index.cache_nr = nr; /* cheap truncate of index */
137                         t1s = getnanotime();
138                         test_lazy_init_name_hash(&the_index, 0);
139                         t2s = getnanotime();
140                         sum_single += (t2s - t1s);
141                         the_index.cache_nr = cache_nr_limit;
142                         discard_cache();
143
144                         read_cache();
145                         the_index.cache_nr = nr; /* cheap truncate of index */
146                         t1m = getnanotime();
147                         nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
148                         t2m = getnanotime();
149                         sum_multi += (t2m - t1m);
150                         the_index.cache_nr = cache_nr_limit;
151                         discard_cache();
152
153                         if (!nr_threads_used)
154                                 printf("    [size %8d] [single %f]   non-threaded code path used\n",
155                                            nr, ((double)(t2s - t1s))/1000000000);
156                         else
157                                 printf("    [size %8d] [single %f] %c [multi %f %d]\n",
158                                            nr,
159                                            ((double)(t2s - t1s))/1000000000,
160                                            (((t2s - t1s) < (t2m - t1m)) ? '<' : '>'),
161                                            ((double)(t2m - t1m))/1000000000,
162                                            nr_threads_used);
163                         fflush(stdout);
164                 }
165                 if (count > 1) {
166                         avg_single = sum_single / count;
167                         avg_multi = sum_multi / count;
168                         if (!nr_threads_used)
169                                 printf("avg [size %8d] [single %f]\n",
170                                            nr,
171                                            (double)avg_single/1000000000);
172                         else
173                                 printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
174                                            nr,
175                                            (double)avg_single/1000000000,
176                                            (avg_single < avg_multi ? '<' : '>'),
177                                            (double)avg_multi/1000000000,
178                                            nr_threads_used);
179                         fflush(stdout);
180                 }
181
182                 if (nr >= cache_nr_limit)
183                         return;
184                 nr += analyze_step;
185         }
186 }
187
188 int cmd__lazy_init_name_hash(int argc, const char **argv)
189 {
190         const char *usage[] = {
191                 "test-tool lazy-init-name-hash -d (-s | -m)",
192                 "test-tool lazy-init-name-hash -p [-c c]",
193                 "test-tool lazy-init-name-hash -a a [--step s] [-c c]",
194                 "test-tool lazy-init-name-hash (-s | -m) [-c c]",
195                 "test-tool lazy-init-name-hash -s -m [-c c]",
196                 NULL
197         };
198         struct option options[] = {
199                 OPT_BOOL('s', "single", &single, "run single-threaded code"),
200                 OPT_BOOL('m', "multi", &multi, "run multi-threaded code"),
201                 OPT_INTEGER('c', "count", &count, "number of passes"),
202                 OPT_BOOL('d', "dump", &dump, "dump hash tables"),
203                 OPT_BOOL('p', "perf", &perf, "compare single vs multi"),
204                 OPT_INTEGER('a', "analyze", &analyze, "analyze different multi sizes"),
205                 OPT_INTEGER(0, "step", &analyze_step, "analyze step factor"),
206                 OPT_END(),
207         };
208         const char *prefix;
209         uint64_t avg_single, avg_multi;
210
211         prefix = setup_git_directory();
212
213         argc = parse_options(argc, argv, prefix, options, usage, 0);
214
215         /*
216          * istate->dir_hash is only created when ignore_case is set.
217          */
218         ignore_case = 1;
219
220         if (dump) {
221                 if (perf || analyze > 0)
222                         die("cannot combine dump, perf, or analyze");
223                 if (count > 1)
224                         die("count not valid with dump");
225                 if (single && multi)
226                         die("cannot use both single and multi with dump");
227                 if (!single && !multi)
228                         die("dump requires either single or multi");
229                 dump_run();
230                 return 0;
231         }
232
233         if (perf) {
234                 if (analyze > 0)
235                         die("cannot combine dump, perf, or analyze");
236                 if (single || multi)
237                         die("cannot use single or multi with perf");
238                 avg_single = time_runs(0);
239                 avg_multi = time_runs(1);
240                 if (avg_multi > avg_single)
241                         die("multi is slower");
242                 return 0;
243         }
244
245         if (analyze) {
246                 if (analyze < 500)
247                         die("analyze must be at least 500");
248                 if (!analyze_step)
249                         analyze_step = analyze;
250                 if (single || multi)
251                         die("cannot use single or multi with analyze");
252                 analyze_run();
253                 return 0;
254         }
255
256         if (!single && !multi)
257                 die("require either -s or -m or both");
258
259         if (single)
260                 time_runs(0);
261         if (multi)
262                 time_runs(1);
263
264         return 0;
265 }