1 #!/usr/sbin/dtrace -qs 2 3 /*- 4 * Copyright (c) 2011-2012 Alexander Leidinger <netchild@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer 12 * in this position and unchanged. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /** 32 * Trace futex operations: 33 * - internal locks 34 * - size of the futex list 35 * - report error conditions (emulation errors, kernel errors, 36 * programming errors) 37 * - execution time (wallclock) of futex related functions 38 */ 39 40 #pragma D option specsize=32m 41 42 /* Error conditions */ 43 linuxulator*:futex:futex_get:error, 44 linuxulator*:futex:futex_sleep:requeue_error, 45 linuxulator*:futex:futex_sleep:sleep_error, 46 linuxulator*:futex:futex_wait:copyin_error, 47 linuxulator*:futex:futex_wait:itimerfix_error, 48 linuxulator*:futex:futex_wait:sleep_error, 49 linuxulator*:futex:futex_atomic_op:missing_access_check, 50 linuxulator*:futex:futex_atomic_op:unimplemented_op, 51 linuxulator*:futex:futex_atomic_op:unimplemented_cmp, 52 linuxulator*:futex:linux_sys_futex:unimplemented_clockswitch, 53 linuxulator*:futex:linux_sys_futex:copyin_error, 54 linuxulator*:futex:linux_sys_futex:unhandled_efault, 55 linuxulator*:futex:linux_sys_futex:unimplemented_lock_pi, 56 linuxulator*:futex:linux_sys_futex:unimplemented_unlock_pi, 57 linuxulator*:futex:linux_sys_futex:unimplemented_trylock_pi, 58 linuxulator*:futex:linux_sys_futex:unimplemented_wait_requeue_pi, 59 linuxulator*:futex:linux_sys_futex:unimplemented_cmp_requeue_pi, 60 linuxulator*:futex:linux_sys_futex:unknown_operation, 61 linuxulator*:futex:linux_get_robust_list:copyout_error, 62 linuxulator*:futex:handle_futex_death:copyin_error, 63 linuxulator*:futex:fetch_robust_entry:copyin_error, 64 linuxulator*:futex:release_futexes:copyin_error 65 { 66 printf("ERROR: %s in %s:%s:%s\n", probename, probeprov, probemod, 67 probefunc); 68 stack(); 69 ustack(); 70 } 71 72 linuxulator*:futex:linux_sys_futex:invalid_cmp_requeue_use, 73 linuxulator*:futex:linux_sys_futex:deprecated_requeue, 74 linuxulator*:futex:linux_set_robust_list:size_error 75 { 76 printf("WARNING: %s:%s:%s:%s in application %s, maybe an application error?\n", 77 probename, probeprov, probemod, probefunc, execname); 78 stack(); 79 ustack(); 80 } 81 82 83 /* Per futex checks/statistics */ 84 85 linuxulator*:futex:futex:create 86 { 87 ++futex_count; 88 @max_futexes = max(futex_count); 89 } 90 91 linuxulator*:futex:futex:destroy 92 /futex_count == 0/ 93 { 94 printf("ERROR: Request to destroy a futex which was not created,\n"); 95 printf(" or this script was started after some futexes where\n"); 96 printf(" created. Stack trace:\n"); 97 stack(); 98 ustack(); 99 } 100 101 linuxulator*:futex:futex:destroy 102 { 103 --futex_count; 104 } 105 106 107 /* Internal locks */ 108 109 linuxulator*:locks:futex_mtx:locked 110 { 111 ++check[probefunc, arg0]; 112 @stats[probefunc] = count(); 113 114 ts[probefunc] = timestamp; 115 spec[probefunc] = speculation(); 116 printf("Stacktrace of last lock operation of the %s:\n", probefunc); 117 stack(); 118 } 119 120 linuxulator*:locks:futex_mtx:unlock 121 /check[probefunc, arg0] == 0/ 122 { 123 printf("ERROR: unlock attempt of unlocked %s (%p),", probefunc, arg0); 124 printf(" missing SDT probe in kernel, or dtrace program started"); 125 printf(" while the %s was already held (race condition).", probefunc); 126 printf(" Stack trace follows:"); 127 stack(); 128 } 129 130 linuxulator*:locks:futex_mtx:unlock 131 { 132 discard(spec[probefunc]); 133 spec[probefunc] = 0; 134 --check[probefunc, arg0]; 135 } 136 137 /* Timeout handling for internal locks */ 138 139 tick-10s 140 /spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/ 141 { 142 commit(spec["futex_mtx"]); 143 spec["futex_mtx"] = 0; 144 } 145 146 147 /* Timing statistings */ 148 149 linuxulator*:futex::entry 150 { 151 self->time[probefunc] = timestamp; 152 @calls[probeprov, execname, probefunc] = count(); 153 } 154 155 linuxulator*:futex::return 156 /self->time[probefunc] != 0/ 157 { 158 this->timediff = self->time[probefunc] - timestamp; 159 160 @timestats[probeprov, execname, probefunc] = quantize(this->timediff); 161 @longest[probeprov, probefunc] = max(this->timediff); 162 163 self->time[probefunc] = 0; 164 } 165 166 167 /* Statistics */ 168 169 END 170 { 171 printf("Number of locks per type:"); 172 printa(@stats); 173 printf("Number of maximum number of futexes in the futex list:"); 174 printa(@max_futexes); 175 printf("Number of futexes still existing: %d", futex_count); 176 printf("Number of calls per provider/application/kernel function:"); 177 printa(@calls); 178 printf("Wallclock-timing statistics per provider/application/kernel function (in ns):"); 179 printa(@timestats); 180 printf("Longest running (wallclock!) functions per provider (in ns):"); 181 printa(@longest); 182 } 183