trace_futexes.d revision 299705
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: stable/10/sys/compat/linux/trace_futexes.d 299705 2016-05-14 00:35:49Z pfg $ 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 */ 43linuxulator*:futex:futex_get:error, 44linuxulator*:futex:futex_sleep:requeue_error, 45linuxulator*:futex:futex_sleep:sleep_error, 46linuxulator*:futex:futex_wait:copyin_error, 47linuxulator*:futex:futex_wait:itimerfix_error, 48linuxulator*:futex:futex_wait:sleep_error, 49linuxulator*:futex:futex_atomic_op:missing_access_check, 50linuxulator*:futex:futex_atomic_op:unimplemented_op, 51linuxulator*:futex:futex_atomic_op:unimplemented_cmp, 52linuxulator*:futex:linux_sys_futex:unimplemented_clockswitch, 53linuxulator*:futex:linux_sys_futex:copyin_error, 54linuxulator*:futex:linux_sys_futex:unhandled_efault, 55linuxulator*:futex:linux_sys_futex:unimplemented_lock_pi, 56linuxulator*:futex:linux_sys_futex:unimplemented_unlock_pi, 57linuxulator*:futex:linux_sys_futex:unimplemented_trylock_pi, 58linuxulator*:futex:linux_sys_futex:unimplemented_wait_requeue_pi, 59linuxulator*:futex:linux_sys_futex:unimplemented_cmp_requeue_pi, 60linuxulator*:futex:linux_sys_futex:unknown_operation, 61linuxulator*:futex:linux_get_robust_list:copyout_error, 62linuxulator*:futex:handle_futex_death:copyin_error, 63linuxulator*:futex:fetch_robust_entry:copyin_error, 64linuxulator*: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 72linuxulator*:futex:linux_sys_futex:invalid_cmp_requeue_use, 73linuxulator*:futex:linux_sys_futex:deprecated_requeue, 74linuxulator*: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 85linuxulator*:futex:futex:create 86{ 87 ++futex_count; 88 @max_futexes = max(futex_count); 89} 90 91linuxulator*: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 101linuxulator*:futex:futex:destroy 102{ 103 --futex_count; 104} 105 106 107/* Internal locks */ 108 109linuxulator*: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 120linuxulator*: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 130linuxulator*: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 139tick-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 149linuxulator*:futex::entry 150{ 151 self->time[probefunc] = timestamp; 152 @calls[probeprov, execname, probefunc] = count(); 153} 154 155linuxulator*: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 169END 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