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 }