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 printf("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 printf("starting benchmarks\n"); 89 printf("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 } 99