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 29 /** 30 * Trace futex operations: 31 * - internal locks 32 * - size of the futex list 33 * - report error conditions (emulation errors, kernel errors, 34 * programming errors) 35 * - execution time (wallclock) of futex related functions 36 */ 37 38 #pragma D option specsize=32m 39 40 /* Error conditions */ 41 linuxulator*:futex:futex_get:error, 42 linuxulator*:futex:futex_sleep:requeue_error, 43 linuxulator*:futex:futex_sleep:sleep_error, 44 linuxulator*:futex:futex_wait:copyin_error, 45 linuxulator*:futex:futex_wait:itimerfix_error, 46 linuxulator*:futex:futex_wait:sleep_error, 47 linuxulator*:futex:futex_atomic_op:missing_access_check, 48 linuxulator*:futex:futex_atomic_op:unimplemented_op, 49 linuxulator*:futex:futex_atomic_op:unimplemented_cmp, 50 linuxulator*:futex:linux_sys_futex:unimplemented_clockswitch, 51 linuxulator*:futex:linux_sys_futex:copyin_error, 52 linuxulator*:futex:linux_sys_futex:unhandled_efault, 53 linuxulator*:futex:linux_sys_futex:unimplemented_lock_pi, 54 linuxulator*:futex:linux_sys_futex:unimplemented_unlock_pi, 55 linuxulator*:futex:linux_sys_futex:unimplemented_trylock_pi, 56 linuxulator*:futex:linux_sys_futex:unimplemented_wait_requeue_pi, 57 linuxulator*:futex:linux_sys_futex:unimplemented_cmp_requeue_pi, 58 linuxulator*:futex:linux_sys_futex:unknown_operation, 59 linuxulator*:futex:linux_get_robust_list:copyout_error, 60 linuxulator*:futex:handle_futex_death:copyin_error, 61 linuxulator*:futex:fetch_robust_entry:copyin_error, 62 linuxulator*:futex:release_futexes:copyin_error 63 { 64 printf("ERROR: %s in %s:%s:%s\n", probename, probeprov, probemod, 65 probefunc); 66 stack(); 67 ustack(); 68 } 69 70 linuxulator*:futex:linux_sys_futex:invalid_cmp_requeue_use, 71 linuxulator*:futex:linux_sys_futex:deprecated_requeue, 72 linuxulator*:futex:linux_set_robust_list:size_error 73 { 74 printf("WARNING: %s:%s:%s:%s in application %s, maybe an application error?\n", 75 probename, probeprov, probemod, probefunc, execname); 76 stack(); 77 ustack(); 78 } 79 80 81 /* Per futex checks/statistics */ 82 83 linuxulator*:futex:futex:create 84 { 85 ++futex_count; 86 @max_futexes = max(futex_count); 87 } 88 89 linuxulator*:futex:futex:destroy 90 /futex_count == 0/ 91 { 92 printf("ERROR: Request to destroy a futex which was not created,\n"); 93 printf(" or this script was started after some futexes where\n"); 94 printf(" created. Stack trace:\n"); 95 stack(); 96 ustack(); 97 } 98 99 linuxulator*:futex:futex:destroy 100 { 101 --futex_count; 102 } 103 104 105 /* Internal locks */ 106 107 linuxulator*:locks:futex_mtx:locked 108 { 109 ++check[probefunc, arg0]; 110 @stats[probefunc] = count(); 111 112 ts[probefunc] = timestamp; 113 spec[probefunc] = speculation(); 114 printf("Stacktrace of last lock operation of the %s:\n", probefunc); 115 stack(); 116 } 117 118 linuxulator*:locks:futex_mtx:unlock 119 /check[probefunc, arg0] == 0/ 120 { 121 printf("ERROR: unlock attempt of unlocked %s (%p),", probefunc, arg0); 122 printf(" missing SDT probe in kernel, or dtrace program started"); 123 printf(" while the %s was already held (race condition).", probefunc); 124 printf(" Stack trace follows:"); 125 stack(); 126 } 127 128 linuxulator*:locks:futex_mtx:unlock 129 { 130 discard(spec[probefunc]); 131 spec[probefunc] = 0; 132 --check[probefunc, arg0]; 133 } 134 135 /* Timeout handling for internal locks */ 136 137 tick-10s 138 /spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/ 139 { 140 commit(spec["futex_mtx"]); 141 spec["futex_mtx"] = 0; 142 } 143 144 145 /* Timing statistings */ 146 147 linuxulator*:futex::entry 148 { 149 self->time[probefunc] = timestamp; 150 @calls[probeprov, execname, probefunc] = count(); 151 } 152 153 linuxulator*:futex::return 154 /self->time[probefunc] != 0/ 155 { 156 this->timediff = self->time[probefunc] - timestamp; 157 158 @timestats[probeprov, execname, probefunc] = quantize(this->timediff); 159 @longest[probeprov, probefunc] = max(this->timediff); 160 161 self->time[probefunc] = 0; 162 } 163 164 165 /* Statistics */ 166 167 END 168 { 169 printf("Number of locks per type:"); 170 printa(@stats); 171 printf("Number of maximum number of futexes in the futex list:"); 172 printa(@max_futexes); 173 printf("Number of futexes still existing: %d", futex_count); 174 printf("Number of calls per provider/application/kernel function:"); 175 printa(@calls); 176 printf("Wallclock-timing statistics per provider/application/kernel function (in ns):"); 177 printa(@timestats); 178 printf("Longest running (wallclock!) functions per provider (in ns):"); 179 printa(@longest); 180 } 181