Andrew's git - gitweb.git/blob - t/helper/test-lazy-init-name-hash.c

   1#include "cache.h"
   2#include "parse-options.h"
   3
   4static int single;
   5static int multi;
   6static int count = 1;
   7static int dump;
   8static int perf;
   9static int analyze;
  10static int analyze_step;
  11
  12/*
  13 * Dump the contents of the "dir" and "name" hash tables to stdout.
  14 * If you sort the result, you can compare it with the other type
  15 * mode and verify that both single and multi produce the same set.
  16 */
  17static void dump_run(void)
  18{
  19        struct hashmap_iter iter_dir;
  20        struct hashmap_iter iter_cache;
  21
  22        /* Stolen from name-hash.c */
  23        struct dir_entry {
  24                struct hashmap_entry ent;
  25                struct dir_entry *parent;
  26                int nr;
  27                unsigned int namelen;
  28                char name[FLEX_ARRAY];
  29        };
  30
  31        struct dir_entry *dir;
  32        struct cache_entry *ce;
  33
  34        read_cache();
  35        if (single) {
  36                test_lazy_init_name_hash(&the_index, 0);
  37        } else {
  38                int nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
  39                if (!nr_threads_used)
  40                        die("non-threaded code path used");
  41        }
  42
  43        dir = hashmap_iter_first(&the_index.dir_hash, &iter_dir);
  44        while (dir) {
  45                printf("dir %08x %7d %s\n", dir->ent.hash, dir->nr, dir->name);
  46                dir = hashmap_iter_next(&iter_dir);
  47        }
  48
  49        ce = hashmap_iter_first(&the_index.name_hash, &iter_cache);
  50        while (ce) {
  51                printf("name %08x %s\n", ce->ent.hash, ce->name);
  52                ce = hashmap_iter_next(&iter_cache);
  53        }
  54
  55        discard_cache();
  56}
  57
  58/*
  59 * Run the single or multi threaded version "count" times and
  60 * report on the time taken.
  61 */
  62static uint64_t time_runs(int try_threaded)
  63{
  64        uint64_t t0, t1, t2;
  65        uint64_t sum = 0;
  66        uint64_t avg;
  67        int nr_threads_used;
  68        int i;
  69
  70        for (i = 0; i < count; i++) {
  71                t0 = getnanotime();
  72                read_cache();
  73                t1 = getnanotime();
  74                nr_threads_used = test_lazy_init_name_hash(&the_index, try_threaded);
  75                t2 = getnanotime();
  76
  77                sum += (t2 - t1);
  78
  79                if (try_threaded && !nr_threads_used)
  80                        die("non-threaded code path used");
  81
  82                if (nr_threads_used)
  83                        printf("%f %f %d multi %d\n",
  84                                   ((double)(t1 - t0))/1000000000,
  85                                   ((double)(t2 - t1))/1000000000,
  86                                   the_index.cache_nr,
  87                                   nr_threads_used);
  88                else
  89                        printf("%f %f %d single\n",
  90                                   ((double)(t1 - t0))/1000000000,
  91                                   ((double)(t2 - t1))/1000000000,
  92                                   the_index.cache_nr);
  93                fflush(stdout);
  94
  95                discard_cache();
  96        }
  97
  98        avg = sum / count;
  99        if (count > 1)
 100                printf("avg %f %s\n",
 101                           (double)avg/1000000000,
 102                           (try_threaded) ? "multi" : "single");
 103
 104        return avg;
 105}
 106
 107/*
 108 * Try a series of runs varying the "istate->cache_nr" and
 109 * try to find a good value for the multi-threaded criteria.
 110 */
 111static void analyze_run(void)
 112{
 113        uint64_t t1s, t1m, t2s, t2m;
 114        int cache_nr_limit;
 115        int nr_threads_used;
 116        int i;
 117        int nr;
 118
 119        read_cache();
 120        cache_nr_limit = the_index.cache_nr;
 121        discard_cache();
 122
 123        nr = analyze;
 124        while (1) {
 125                uint64_t sum_single = 0;
 126                uint64_t sum_multi = 0;
 127                uint64_t avg_single;
 128                uint64_t avg_multi;
 129
 130                if (nr > cache_nr_limit)
 131                        nr = cache_nr_limit;
 132
 133                for (i = 0; i < count; i++) {
 134                        read_cache();
 135                        the_index.cache_nr = nr; /* cheap truncate of index */
 136                        t1s = getnanotime();
 137                        test_lazy_init_name_hash(&the_index, 0);
 138                        t2s = getnanotime();
 139                        sum_single += (t2s - t1s);
 140                        the_index.cache_nr = cache_nr_limit;
 141                        discard_cache();
 142
 143                        read_cache();
 144                        the_index.cache_nr = nr; /* cheap truncate of index */
 145                        t1m = getnanotime();
 146                        nr_threads_used = test_lazy_init_name_hash(&the_index, 1);
 147                        t2m = getnanotime();
 148                        sum_multi += (t2m - t1m);
 149                        the_index.cache_nr = cache_nr_limit;
 150                        discard_cache();
 151
 152                        if (!nr_threads_used)
 153                                printf("    [size %8d] [single %f]   non-threaded code path used\n",
 154                                           nr, ((double)(t2s - t1s))/1000000000);
 155                        else
 156                                printf("    [size %8d] [single %f] %c [multi %f %d]\n",
 157                                           nr,
 158                                           ((double)(t2s - t1s))/1000000000,
 159                                           (((t2s - t1s) < (t2m - t1m)) ? '<' : '>'),
 160                                           ((double)(t2m - t1m))/1000000000,
 161                                           nr_threads_used);
 162                        fflush(stdout);
 163                }
 164                if (count > 1) {
 165                        avg_single = sum_single / count;
 166                        avg_multi = sum_multi / count;
 167                        if (!nr_threads_used)
 168                                printf("avg [size %8d] [single %f]\n",
 169                                           nr,
 170                                           (double)avg_single/1000000000);
 171                        else
 172                                printf("avg [size %8d] [single %f] %c [multi %f %d]\n",
 173                                           nr,
 174                                           (double)avg_single/1000000000,
 175                                           (avg_single < avg_multi ? '<' : '>'),
 176                                           (double)avg_multi/1000000000,
 177                                           nr_threads_used);
 178                        fflush(stdout);
 179                }
 180
 181                if (nr >= cache_nr_limit)
 182                        return;
 183                nr += analyze_step;
 184        }
 185}
 186
 187int cmd_main(int argc, const char **argv)
 188{
 189        const char *usage[] = {
 190                "test-lazy-init-name-hash -d (-s | -m)",
 191                "test-lazy-init-name-hash -p [-c c]",
 192                "test-lazy-init-name-hash -a a [--step s] [-c c]",
 193                "test-lazy-init-name-hash (-s | -m) [-c c]",
 194                "test-lazy-init-name-hash -s -m [-c c]",
 195                NULL
 196        };
 197        struct option options[] = {
 198                OPT_BOOL('s', "single", &single, "run single-threaded code"),
 199                OPT_BOOL('m', "multi", &multi, "run multi-threaded code"),
 200                OPT_INTEGER('c', "count", &count, "number of passes"),
 201                OPT_BOOL('d', "dump", &dump, "dump hash tables"),
 202                OPT_BOOL('p', "perf", &perf, "compare single vs multi"),
 203                OPT_INTEGER('a', "analyze", &analyze, "analyze different multi sizes"),
 204                OPT_INTEGER(0, "step", &analyze_step, "analyze step factor"),
 205                OPT_END(),
 206        };
 207        const char *prefix;
 208        uint64_t avg_single, avg_multi;
 209
 210        prefix = setup_git_directory();
 211
 212        argc = parse_options(argc, argv, prefix, options, usage, 0);
 213
 214        /*
 215         * istate->dir_hash is only created when ignore_case is set.
 216         */
 217        ignore_case = 1;
 218
 219        if (dump) {
 220                if (perf || analyze > 0)
 221                        die("cannot combine dump, perf, or analyze");
 222                if (count > 1)
 223                        die("count not valid with dump");
 224                if (single && multi)
 225                        die("cannot use both single and multi with dump");
 226                if (!single && !multi)
 227                        die("dump requires either single or multi");
 228                dump_run();
 229                return 0;
 230        }
 231
 232        if (perf) {
 233                if (analyze > 0)
 234                        die("cannot combine dump, perf, or analyze");
 235                if (single || multi)
 236                        die("cannot use single or multi with perf");
 237                avg_single = time_runs(0);
 238                avg_multi = time_runs(1);
 239                if (avg_multi > avg_single)
 240                        die("multi is slower");
 241                return 0;
 242        }
 243
 244        if (analyze) {
 245                if (analyze < 500)
 246                        die("analyze must be at least 500");
 247                if (!analyze_step)
 248                        analyze_step = analyze;
 249                if (single || multi)
 250                        die("cannot use single or multi with analyze");
 251                analyze_run();
 252                return 0;
 253        }
 254
 255        if (!single && !multi)
 256                die("require either -s or -m or both");
 257
 258        if (single)
 259                time_runs(0);
 260        if (multi)
 261                time_runs(1);
 262
 263        return 0;
 264}