kern_lockstat.c revision 285759 
1/*-
2 * Copyright 2008-2009 Stacey Son <sson@FreeBSD.org>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD: stable/10/sys/kern/kern_lockstat.c 285759 2015-07-21 17:16:37Z markj $
26 */
27
28/*
29 * Backend for the lock tracing (lockstat) kernel support. This is required
30 * to allow a module to load even though DTrace kernel support may not be
31 * present.
32 *
33 */
34
35#include "opt_kdtrace.h"
36
37#ifdef KDTRACE_HOOKS
38
39#include <sys/types.h>
40#include <sys/lock.h>
41#include <sys/lockstat.h>
42#include <sys/time.h>
43
44/*
45 * The following must match the type definition of dtrace_probe.  It is
46 * defined this way to avoid having to rely on CDDL code.
47 */
48uint32_t lockstat_probemap[LS_NPROBES];
49void (*lockstat_probe_func)(uint32_t, uintptr_t, uintptr_t,
50    uintptr_t, uintptr_t, uintptr_t);
51int lockstat_enabled = 0;
52
53uint64_t
54lockstat_nsecs(struct lock_object *lo)
55{
56	struct bintime bt;
57	uint64_t ns;
58
59	if (!lockstat_enabled)
60		return (0);
61	if ((lo->lo_flags & LO_NOPROFILE) != 0)
62		return (0);
63
64	binuptime(&bt);
65	ns = bt.sec * (uint64_t)1000000000;
66	ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32;
67	return (ns);
68}
69
70#endif /* KDTRACE_HOOKS */
71