#!/usr/sbin/dtrace -qs
/*-
* Copyright (c) 2011-2012 Alexander Leidinger <netchild@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
/**
* Trace futex operations:
* - internal locks
* - size of the futex list
* - report error conditions (emulation errors, kernel errors,
* programming errors)
* - execution time (wallclock) of futex related functions
*/
#pragma D option specsize=32m
/* Error conditions */
linuxulator*:futex:futex_get:error,
linuxulator*:futex:futex_sleep:requeue_error,
linuxulator*:futex:futex_sleep:sleep_error,
linuxulator*:futex:futex_wait:copyin_error,
linuxulator*:futex:futex_wait:itimerfix_error,
linuxulator*:futex:futex_wait:sleep_error,
linuxulator*:futex:futex_atomic_op:missing_access_check,
linuxulator*:futex:futex_atomic_op:unimplemented_op,
linuxulator*:futex:futex_atomic_op:unimplemented_cmp,
linuxulator*:futex:linux_sys_futex:unimplemented_clockswitch,
linuxulator*:futex:linux_sys_futex:copyin_error,
linuxulator*:futex:linux_sys_futex:unhandled_efault,
linuxulator*:futex:linux_sys_futex:unimplemented_lock_pi,
linuxulator*:futex:linux_sys_futex:unimplemented_unlock_pi,
linuxulator*:futex:linux_sys_futex:unimplemented_trylock_pi,
linuxulator*:futex:linux_sys_futex:unimplemented_wait_requeue_pi,
linuxulator*:futex:linux_sys_futex:unimplemented_cmp_requeue_pi,
linuxulator*:futex:linux_sys_futex:unknown_operation,
linuxulator*:futex:linux_get_robust_list:copyout_error,
linuxulator*:futex:handle_futex_death:copyin_error,
linuxulator*:futex:fetch_robust_entry:copyin_error,
linuxulator*:futex:release_futexes:copyin_error
{
printf("ERROR: %s in %s:%s:%s\n", probename, probeprov, probemod,
probefunc);
stack();
ustack();
}
linuxulator*:futex:linux_sys_futex:invalid_cmp_requeue_use,
linuxulator*:futex:linux_sys_futex:deprecated_requeue,
linuxulator*:futex:linux_set_robust_list:size_error
{
printf("WARNING: %s:%s:%s:%s in application %s, maybe an application error?\n",
probename, probeprov, probemod, probefunc, execname);
stack();
ustack();
}
/* Per futex checks/statistics */
linuxulator*:futex:futex:create
{
++futex_count;
@max_futexes = max(futex_count);
}
linuxulator*:futex:futex:destroy
/futex_count == 0/
{
printf("ERROR: Request to destroy a futex which was not created,\n");
printf(" or this script was started after some futexes where\n");
printf(" created. Stack trace:\n");
stack();
ustack();
}
linuxulator*:futex:futex:destroy
{
--futex_count;
}
/* Internal locks */
linuxulator*:locks:futex_mtx:locked
{
++check[probefunc, arg0];
@stats[probefunc] = count();
ts[probefunc] = timestamp;
spec[probefunc] = speculation();
printf("Stacktrace of last lock operation of the %s:\n", probefunc);
stack();
}
linuxulator*:locks:futex_mtx:unlock
/check[probefunc, arg0] == 0/
{
printf("ERROR: unlock attempt of unlocked %s (%p),", probefunc, arg0);
printf(" missing SDT probe in kernel, or dtrace program started");
printf(" while the %s was already held (race condition).", probefunc);
printf(" Stack trace follows:");
stack();
}
linuxulator*:locks:futex_mtx:unlock
{
discard(spec[probefunc]);
spec[probefunc] = 0;
--check[probefunc, arg0];
}
/* Timeout handling for internal locks */
tick-10s
/spec["futex_mtx"] != 0 && timestamp - ts["futex_mtx"] >= 9999999000/
{
commit(spec["futex_mtx"]);
spec["futex_mtx"] = 0;
}
/* Timing statistings */
linuxulator*:futex::entry
{
self->time[probefunc] = timestamp;
@calls[probeprov, execname, probefunc] = count();
}
linuxulator*:futex::return
/self->time[probefunc] != 0/
{
this->timediff = self->time[probefunc] - timestamp;
@timestats[probeprov, execname, probefunc] = quantize(this->timediff);
@longest[probeprov, probefunc] = max(this->timediff);
self->time[probefunc] = 0;
}
/* Statistics */
END
{
printf("Number of locks per type:");
printa(@stats);
printf("Number of maximum number of futexes in the futex list:");
printa(@max_futexes);
printf("Number of futexes still existing: %d", futex_count);
printf("Number of calls per provider/application/kernel function:");
printa(@calls);
printf("Wallclock-timing statistics per provider/application/kernel function (in ns):");
printa(@timestats);
printf("Longest running (wallclock!) functions per provider (in ns):");
printa(@longest);
}
