benchtests/bench-bzero-walk.c

   1 /* Measure memset function throughput with large data sizes.
   2    Copyright (C) 2017-2023 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 #define TEST_MAIN
  20 #ifdef DO_MEMSET
  21 # define TEST_NAME "memset"
  22 #else
  23 # define TEST_NAME "bzero"
  24 #endif
  25 #define START_SIZE 128
  26 #define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
  27 #define TIMEOUT (20 * 60)
  28 #include "bench-string.h"
  29
  30 #include "json-lib.h"
  31
  32 #ifdef DO_MEMSET
  33 void *generic_memset (void *, int, size_t);
  34
  35 typedef void *(*proto_t) (void *, int, size_t);
  36
  37 IMPL (memset, 1)
  38 IMPL (generic_memset, 0)
  39
  40 #else
  41 static void
  42 memset_zero (void * s, size_t len)
  43 {
  44   memset (s, '\0', len);
  45 }
  46
  47 typedef void (*proto_t) (void *, size_t);
  48
  49 IMPL (bzero, 1)
  50 IMPL (memset_zero, 0)
  51 #endif
  52
  53 static void
  54 do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
  55              size_t n)
  56 {
  57   size_t i, iters = MIN_PAGE_SIZE / n;
  58   timing_t start, stop, cur;
  59
  60   TIMING_NOW (start);
  61   for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
  62 #ifdef DO_MEMSET
  63     CALL (impl, s, 0, n);
  64 #else
  65     CALL (impl, s, n);
  66 #endif
  67   TIMING_NOW (stop);
  68
  69   TIMING_DIFF (cur, start, stop);
  70
  71   /* Get time taken per function call.  */
  72   json_element_double (json_ctx, (double) cur / i);
  73 }
  74
  75 static void
  76 do_test (json_ctx_t *json_ctx, size_t len)
  77 {
  78   json_element_object_begin (json_ctx);
  79   json_attr_uint (json_ctx, "length", len);
  80   json_array_begin (json_ctx, "timings");
  81
  82   FOR_EACH_IMPL (impl, 0)
  83     {
  84       do_one_test (json_ctx, impl, (CHAR *) buf1,
  85                    (CHAR *) buf1 + MIN_PAGE_SIZE - len, len);
  86       alloc_bufs ();
  87     }
  88
  89   json_array_end (json_ctx);
  90   json_element_object_end (json_ctx);
  91 }
  92
  93 int
  94 test_main (void)
  95 {
  96   json_ctx_t json_ctx;
  97   size_t i;
  98
  99   test_init ();
 100
 101   json_init (&json_ctx, 0, stdout);
 102
 103   json_document_begin (&json_ctx);
 104   json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
 105
 106   json_attr_object_begin (&json_ctx, "functions");
 107   json_attr_object_begin (&json_ctx, TEST_NAME);
 108   json_attr_string (&json_ctx, "bench-variant", "walk");
 109
 110   json_array_begin (&json_ctx, "ifuncs");
 111   FOR_EACH_IMPL (impl, 0)
 112     json_element_string (&json_ctx, impl->name);
 113   json_array_end (&json_ctx);
 114
 115   json_array_begin (&json_ctx, "results");
 116   for (i = 1; i <= 64; i++)
 117     do_test (&json_ctx, i);
 118
 119   for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
 120     {
 121       do_test (&json_ctx, i);
 122       do_test (&json_ctx, i + 1);
 123     }
 124
 125   json_array_end (&json_ctx);
 126   json_attr_object_end (&json_ctx);
 127   json_attr_object_end (&json_ctx);
 128   json_document_end (&json_ctx);
 129
 130   return ret;
 131 }
 132
 133 #include <support/test-driver.c>
 134
 135 #ifdef DO_MEMSET
 136 # define libc_hidden_builtin_def(X)
 137 # define libc_hidden_def(X)
 138 # define libc_hidden_weak(X)
 139 # define weak_alias(X,Y)
 140 # undef MEMSET
 141 # define MEMSET generic_memset
 142 # include <string/memset.c>
 143 #endif