tools/testing/radix-tree/benchmark.c

   1 /*
   2  * benchmark.c:
   3  * Author: Konstantin Khlebnikov <koct9i@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14 #include <linux/radix-tree.h>
  15 #include <linux/slab.h>
  16 #include <linux/errno.h>
  17 #include <time.h>
  18 #include "test.h"
  19
  20 #define NSEC_PER_SEC    1000000000L
  21
  22 static long long benchmark_iter(struct radix_tree_root *root, bool tagged)
  23 {
  24         volatile unsigned long sink = 0;
  25         struct radix_tree_iter iter;
  26         struct timespec start, finish;
  27         long long nsec;
  28         int l, loops = 1;
  29         void **slot;
  30
  31 #ifdef BENCHMARK
  32 again:
  33 #endif
  34         clock_gettime(CLOCK_MONOTONIC, &start);
  35         for (l = 0; l < loops; l++) {
  36                 if (tagged) {
  37                         radix_tree_for_each_tagged(slot, root, &iter, 0, 0)
  38                                 sink ^= (unsigned long)slot;
  39                 } else {
  40                         radix_tree_for_each_slot(slot, root, &iter, 0)
  41                                 sink ^= (unsigned long)slot;
  42                 }
  43         }
  44         clock_gettime(CLOCK_MONOTONIC, &finish);
  45
  46         nsec = (finish.tv_sec - start.tv_sec) * NSEC_PER_SEC +
  47                (finish.tv_nsec - start.tv_nsec);
  48
  49 #ifdef BENCHMARK
  50         if (loops == 1 && nsec * 5 < NSEC_PER_SEC) {
  51                 loops = NSEC_PER_SEC / nsec / 4 + 1;
  52                 goto again;
  53         }
  54 #endif
  55
  56         nsec /= loops;
  57         return nsec;
  58 }
  59
  60 static void benchmark_size(unsigned long size, unsigned long step, int order)
  61 {
  62         RADIX_TREE(tree, GFP_KERNEL);
  63         long long normal, tagged;
  64         unsigned long index;
  65
  66         for (index = 0 ; index < size ; index += step) {
  67                 item_insert_order(&tree, index, order);
  68                 radix_tree_tag_set(&tree, index, 0);
  69         }
  70
  71         tagged = benchmark_iter(&tree, true);
  72         normal = benchmark_iter(&tree, false);
  73
  74         printv(2, "Size %ld, step %6ld, order %d tagged %10lld ns, normal %10lld ns\n",
  75                 size, step, order, tagged, normal);
  76
  77         item_kill_tree(&tree);
  78         rcu_barrier();
  79 }
  80
  81 void benchmark(void)
  82 {
  83         unsigned long size[] = {1 << 10, 1 << 20, 0};
  84         unsigned long step[] = {1, 2, 7, 15, 63, 64, 65,
  85                                 128, 256, 512, 12345, 0};
  86         int c, s;
  87
  88         printv(1, "starting benchmarks\n");
  89         printv(1, "RADIX_TREE_MAP_SHIFT = %d\n", RADIX_TREE_MAP_SHIFT);
  90
  91         for (c = 0; size[c]; c++)
  92                 for (s = 0; step[s]; s++)
  93                         benchmark_size(size[c], step[s], 0);
  94
  95         for (c = 0; size[c]; c++)
  96                 for (s = 0; step[s]; s++)
  97                         benchmark_size(size[c], step[s] << 9, 9);
  98 }