benchtests/bench-skeleton.c

   1 /* Skeleton for benchmark programs.
   2    Copyright (C) 2013-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <string.h>
  20 #include <stdint.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <time.h>
  24 #include <inttypes.h>
  25 #include "bench-timing.h"
  26 #include "json-lib.h"
  27 #include "bench-util.h"
  28
  29 #include "bench-util.c"
  30
  31 #define TIMESPEC_AFTER(a, b) \
  32   (((a).tv_sec == (b).tv_sec)                                                 \
  33    ? ((a).tv_nsec > (b).tv_nsec)                                              \
  34    : ((a).tv_sec > (b).tv_sec))
  35 int
  36 main (int argc, char **argv)
  37 {
  38   unsigned long i, k;
  39   struct timespec runtime;
  40   timing_t start, end;
  41   bool detailed = false;
  42   json_ctx_t json_ctx;
  43
  44   if (argc == 2 && !strcmp (argv[1], "-d"))
  45     detailed = true;
  46
  47   bench_start ();
  48
  49   memset (&runtime, 0, sizeof (runtime));
  50
  51   unsigned long iters = 1000;
  52
  53 #ifdef BENCH_INIT
  54   BENCH_INIT ();
  55 #endif
  56
  57   json_init (&json_ctx, 2, stdout);
  58
  59   /* Begin function.  */
  60   json_attr_object_begin (&json_ctx, FUNCNAME);
  61
  62   for (int v = 0; v < NUM_VARIANTS; v++)
  63     {
  64       /* Run for approximately DURATION seconds.  */
  65       clock_gettime (CLOCK_MONOTONIC_RAW, &runtime);
  66       runtime.tv_sec += DURATION;
  67
  68       bool is_bench = strncmp (VARIANT (v), "workload-", 9) == 0;
  69       double d_total_i = 0;
  70       timing_t total = 0, max = 0, min = 0x7fffffffffffffff;
  71       timing_t throughput = 0, latency = 0;
  72       int64_t c = 0;
  73       uint64_t cur;
  74       BENCH_VARS;
  75       while (1)
  76         {
  77           if (is_bench)
  78             {
  79               /* Benchmark a real trace of calls - all samples are iterated
  80                  over once before repeating.  This models actual use more
  81                  accurately than repeating the same sample many times.  */
  82               TIMING_NOW (start);
  83               for (k = 0; k < iters; k++)
  84                 for (i = 0; i < NUM_SAMPLES (v); i++)
  85                   BENCH_FUNC (v, i);
  86               TIMING_NOW (end);
  87               TIMING_DIFF (cur, start, end);
  88               TIMING_ACCUM (throughput, cur);
  89
  90               TIMING_NOW (start);
  91               for (k = 0; k < iters; k++)
  92                 for (i = 0; i < NUM_SAMPLES (v); i++)
  93                   BENCH_FUNC_LAT (v, i);
  94               TIMING_NOW (end);
  95               TIMING_DIFF (cur, start, end);
  96               TIMING_ACCUM (latency, cur);
  97
  98               d_total_i += iters * NUM_SAMPLES (v);
  99             }
 100           else
 101             for (i = 0; i < NUM_SAMPLES (v); i++)
 102               {
 103                 TIMING_NOW (start);
 104                 for (k = 0; k < iters; k++)
 105                   BENCH_FUNC (v, i);
 106                 TIMING_NOW (end);
 107
 108                 TIMING_DIFF (cur, start, end);
 109
 110                 if (cur > max)
 111                   max = cur;
 112
 113                 if (cur < min)
 114                   min = cur;
 115
 116                 TIMING_ACCUM (total, cur);
 117                 /* Accumulate timings for the value.  In the end we will divide
 118                    by the total iterations.  */
 119                 RESULT_ACCUM (cur, v, i, c * iters, (c + 1) * iters);
 120
 121                 d_total_i += iters;
 122               }
 123           c++;
 124           struct timespec curtime;
 125
 126           memset (&curtime, 0, sizeof (curtime));
 127           clock_gettime (CLOCK_MONOTONIC_RAW, &curtime);
 128           if (TIMESPEC_AFTER (curtime, runtime))
 129             goto done;
 130         }
 131
 132       double d_total_s;
 133       double d_iters;
 134
 135     done:
 136       d_total_s = total;
 137       d_iters = iters;
 138
 139       /* Begin variant.  */
 140       json_attr_object_begin (&json_ctx, VARIANT (v));
 141
 142       if (is_bench)
 143         {
 144           json_attr_double (&json_ctx, "duration", throughput + latency);
 145           json_attr_double (&json_ctx, "iterations", 2 * d_total_i);
 146           json_attr_double (&json_ctx, "reciprocal-throughput",
 147                             throughput / d_total_i);
 148           json_attr_double (&json_ctx, "latency", latency / d_total_i);
 149           json_attr_double (&json_ctx, "max-throughput",
 150                             d_total_i / throughput * 1000000000.0);
 151           json_attr_double (&json_ctx, "min-throughput",
 152                             d_total_i / latency * 1000000000.0);
 153         }
 154       else
 155         {
 156           json_attr_double (&json_ctx, "duration", d_total_s);
 157           json_attr_double (&json_ctx, "iterations", d_total_i);
 158           json_attr_double (&json_ctx, "max", max / d_iters);
 159           json_attr_double (&json_ctx, "min", min / d_iters);
 160           json_attr_double (&json_ctx, "mean", d_total_s / d_total_i);
 161         }
 162
 163       if (detailed && !is_bench)
 164         {
 165           json_array_begin (&json_ctx, "timings");
 166
 167           for (int i = 0; i < NUM_SAMPLES (v); i++)
 168             json_element_double (&json_ctx, RESULT (v, i));
 169
 170           json_array_end (&json_ctx);
 171         }
 172
 173       /* End variant.  */
 174       json_attr_object_end (&json_ctx);
 175     }
 176
 177   /* End function.  */
 178   json_attr_object_end (&json_ctx);
 179
 180   return 0;
 181 }