1/* libunwind - a platform-independent unwind library 2 Copyright (C) 2003-2004 Hewlett-Packard Co 3 Contributed by David Mosberger-Tang <davidm@hpl.hp.com> 4 5Permission is hereby granted, free of charge, to any person obtaining 6a copy of this software and associated documentation files (the 7"Software"), to deal in the Software without restriction, including 8without limitation the rights to use, copy, modify, merge, publish, 9distribute, sublicense, and/or sell copies of the Software, and to 10permit persons to whom the Software is furnished to do so, subject to 11the following conditions: 12 13The above copyright notice and this permission notice shall be 14included in all copies or substantial portions of the Software. 15 16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 20LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 21OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 22WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ 23 24#include <string.h> 25#include <stdio.h> 26#include <stdlib.h> 27#include <unistd.h> 28 29#include <libunwind.h> 30#include "compiler.h" 31 32#include <sys/resource.h> 33#include <sys/time.h> 34 35#define panic(args...) \ 36 do { fprintf (stderr, args); exit (-1); } while (0) 37 38long dummy; 39 40static long iterations = 10000; 41static int maxlevel = 100; 42 43#define KB 1024 44#define MB (1024*1024) 45 46static char big[64*MB]; /* should be >> max. cache size */ 47 48static inline double 49gettime (void) 50{ 51 struct timeval tv; 52 53 gettimeofday (&tv, NULL); 54 return tv.tv_sec + 1e-6*tv.tv_usec; 55} 56 57static int NOINLINE 58measure_unwind (int maxlevel, double *step) 59{ 60 double stop, start; 61 int level = 0; 62 void *buffer[128]; 63 64 start = gettime (); 65 level = unw_backtrace(buffer, 128); 66 stop = gettime (); 67 68 if (level <= maxlevel) 69 panic ("Unwound only %d levels, expected at least %d levels\n", 70 level, maxlevel); 71 72 *step = (stop - start) / (double) level; 73 return 0; 74} 75 76static int f1 (int, int, double *); 77 78static int NOINLINE 79g1 (int level, int maxlevel, double *step) 80{ 81 if (level == maxlevel) 82 return measure_unwind (maxlevel, step); 83 else 84 /* defeat last-call/sibcall optimization */ 85 return f1 (level + 1, maxlevel, step) + level; 86} 87 88static int NOINLINE 89f1 (int level, int maxlevel, double *step) 90{ 91 if (level == maxlevel) 92 return measure_unwind (maxlevel, step); 93 else 94 /* defeat last-call/sibcall optimization */ 95 return g1 (level + 1, maxlevel, step) + level; 96} 97 98static void 99doit (const char *label) 100{ 101 double step, min_step, first_step, sum_step; 102 int i; 103 104 sum_step = first_step = 0.0; 105 min_step = 1e99; 106 for (i = 0; i < iterations; ++i) 107 { 108 f1 (0, maxlevel, &step); 109 110 sum_step += step; 111 112 if (step < min_step) 113 min_step = step; 114 115 if (i == 0) 116 first_step = step; 117 } 118 printf ("%s: unw_step : 1st=%9.3f min=%9.3f avg=%9.3f nsec\n", label, 119 1e9*first_step, 1e9*min_step, 1e9*sum_step/iterations); 120} 121 122static long 123sum (void *buf, size_t size) 124{ 125 long s = 0; 126 char *cp = buf; 127 size_t i; 128 129 for (i = 0; i < size; i += 8) 130 s += cp[i]; 131 return s; 132} 133 134static void 135measure_init (void) 136{ 137# define N 100 138# define M 10 /* must be at least 2 to get steady-state */ 139 double stop, start, get_cold, get_warm, init_cold, init_warm, delta; 140 struct 141 { 142 unw_cursor_t c; 143 char padding[1024]; /* should be > 2 * max. cacheline size */ 144 } 145 cursor[N]; 146 struct 147 { 148 unw_context_t uc; 149 char padding[1024]; /* should be > 2 * max. cacheline size */ 150 } 151 uc[N]; 152 int i, j; 153 154 /* Run each test M times and take the minimum to filter out noise 155 such dynamic linker resolving overhead, context-switches, 156 page-in, cache, and TLB effects. */ 157 158 get_cold = 1e99; 159 for (j = 0; j < M; ++j) 160 { 161 dummy += sum (big, sizeof (big)); /* flush the cache */ 162 for (i = 0; i < N; ++i) 163 uc[i].padding[511] = i; /* warm up the TLB */ 164 start = gettime (); 165 for (i = 0; i < N; ++i) 166 unw_getcontext (&uc[i].uc); 167 stop = gettime (); 168 delta = (stop - start) / N; 169 if (delta < get_cold) 170 get_cold = delta; 171 } 172 173 init_cold = 1e99; 174 for (j = 0; j < M; ++j) 175 { 176 dummy += sum (big, sizeof (big)); /* flush cache */ 177 for (i = 0; i < N; ++i) 178 uc[i].padding[511] = i; /* warm up the TLB */ 179 start = gettime (); 180 for (i = 0; i < N; ++i) 181 unw_init_local (&cursor[i].c, &uc[i].uc); 182 stop = gettime (); 183 delta = (stop - start) / N; 184 if (delta < init_cold) 185 init_cold = delta; 186 } 187 188 get_warm = 1e99; 189 for (j = 0; j < M; ++j) 190 { 191 start = gettime (); 192 for (i = 0; i < N; ++i) 193 unw_getcontext (&uc[0].uc); 194 stop = gettime (); 195 delta = (stop - start) / N; 196 if (delta < get_warm) 197 get_warm = delta; 198 } 199 200 init_warm = 1e99; 201 for (j = 0; j < M; ++j) 202 { 203 start = gettime (); 204 for (i = 0; i < N; ++i) 205 unw_init_local (&cursor[0].c, &uc[0].uc); 206 stop = gettime (); 207 delta = (stop - start) / N; 208 if (delta < init_warm) 209 init_warm = delta; 210 } 211 212 printf ("unw_getcontext : cold avg=%9.3f nsec, warm avg=%9.3f nsec\n", 213 1e9 * get_cold, 1e9 * get_warm); 214 printf ("unw_init_local : cold avg=%9.3f nsec, warm avg=%9.3f nsec\n", 215 1e9 * init_cold, 1e9 * init_warm); 216} 217 218int 219main (int argc, char **argv) 220{ 221 struct rlimit rlim; 222 223 rlim.rlim_cur = RLIM_INFINITY; 224 rlim.rlim_max = RLIM_INFINITY; 225 setrlimit (RLIMIT_STACK, &rlim); 226 227 memset (big, 0xaa, sizeof (big)); 228 229 if (argc > 1) 230 { 231 maxlevel = atol (argv[1]); 232 if (argc > 2) 233 iterations = atol (argv[2]); 234 } 235 236 measure_init (); 237 238 unw_set_caching_policy (unw_local_addr_space, UNW_CACHE_NONE); 239 doit ("no cache "); 240 241 unw_set_caching_policy (unw_local_addr_space, UNW_CACHE_GLOBAL); 242 doit ("global cache "); 243 244 unw_set_caching_policy (unw_local_addr_space, UNW_CACHE_PER_THREAD); 245 doit ("per-thread cache"); 246 247 return 0; 248} 249