xref: /freebsd/sys/sys/lock_profile.h (revision 282a3889ebf826db9839be296ff1dd903f6d6d6e)
1 /*-
2  * Copyright (c) 2006 Kip Macy kmacy@FreeBSD.org
3  * Copyright (c) 2006 Kris Kennaway kris@FreeBSD.org
4  * Copyright (c) 2006 Dag-Erling Smorgrav des@des.no
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHAL THE AUTHORS BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  *
27  * $FreeBSD$
28  */
29 
30 
31 #ifndef _SYS_LOCK_PROFILE_H_
32 #define _SYS_LOCK_PROFILE_H_
33 
34 #ifdef LOCK_PROFILING
35 #include <sys/stdint.h>
36 #include <sys/ktr.h>
37 #include <sys/mutex.h>
38 #include <machine/atomic.h>
39 #include <machine/cpufunc.h>
40 
41 #ifndef LPROF_HASH_SIZE
42 #define LPROF_HASH_SIZE		4096
43 #define LPROF_HASH_MASK		(LPROF_HASH_SIZE - 1)
44 #endif
45 
46 #ifndef USE_CPU_NANOSECONDS
47 u_int64_t nanoseconds(void);
48 #endif
49 
50 struct lock_prof {
51 	const char	*name;
52 	const char      *type;
53 	const char	*file;
54 	u_int		 namehash;
55 	int		line;
56 	uintmax_t	cnt_max;
57 	uintmax_t	cnt_tot;
58 	uintmax_t       cnt_wait;
59 	uintmax_t	cnt_cur;
60 	uintmax_t	cnt_contest_holding;
61 	uintmax_t	cnt_contest_locking;
62 };
63 
64 extern struct lock_prof lprof_buf[LPROF_HASH_SIZE];
65 #define LPROF_SBUF_SIZE		256 * 400
66 
67 /* We keep a smaller pool of spin mutexes for protecting the lprof hash entries */
68 #define LPROF_LOCK_SIZE         16
69 #define LPROF_LOCK_MASK         (LPROF_LOCK_SIZE - 1)
70 #define LPROF_LHASH(hash)       ((hash) & LPROF_LOCK_MASK)
71 
72 #define LPROF_LOCK(hash)        mtx_lock_spin(&lprof_locks[LPROF_LHASH(hash)])
73 #define LPROF_UNLOCK(hash)      mtx_unlock_spin(&lprof_locks[LPROF_LHASH(hash)])
74 
75 #ifdef _KERNEL
76 extern struct mtx lprof_locks[LPROF_LOCK_SIZE];
77 extern int lock_prof_enable;
78 
79 void _lock_profile_obtain_lock_success(struct lock_object *lo, int contested, uint64_t waittime, const char *file, int line);
80 void _lock_profile_update_wait(struct lock_object *lo, uint64_t waitstart);
81 void _lock_profile_release_lock(struct lock_object *lo);
82 
83 static inline void lock_profile_object_init(struct lock_object *lo, struct lock_class *class, const char *name) {
84 	const char *p;
85 	u_int hash = 0;
86 	struct lock_profile_object *l = &lo->lo_profile_obj;
87 
88 	l->lpo_acqtime = 0;
89 	l->lpo_waittime = 0;
90 	l->lpo_filename = NULL;
91 	l->lpo_lineno = 0;
92 	l->lpo_contest_holding = 0;
93 	l->lpo_contest_locking = 0;
94 	l->lpo_type = class->lc_name;
95 
96 	/* Hash the mutex name to an int so we don't have to strcmp() it repeatedly */
97 	for (p = name; *p != '\0'; p++)
98 		hash = 31 * hash + *p;
99 	l->lpo_namehash = hash;
100 #if 0
101 	if (opts & MTX_PROFILE)
102 		l->lpo_stack = stack_create();
103 #endif
104 }
105 
106 
107 static inline void
108 lock_profile_object_destroy(struct lock_object *lo)
109 {
110 #if 0
111 	struct lock_profile_object *l = &lo->lo_profile_obj;
112 	if (lo->lo_flags & LO_PROFILE)
113 		stack_destroy(l->lpo_stack);
114 #endif
115 }
116 
117 static inline void lock_profile_obtain_lock_failed(struct lock_object *lo, int *contested,
118     uint64_t *waittime)
119 {
120 	struct lock_profile_object *l = &lo->lo_profile_obj;
121 
122 	if (lock_prof_enable && *contested == 0) {
123 		*waittime = nanoseconds();
124 		atomic_add_int(&l->lpo_contest_holding, 1);
125 		*contested = 1;
126 	}
127 }
128 
129 static inline void lock_profile_obtain_lock_success(struct lock_object *lo, int contested, uint64_t waittime, const char *file, int line)
130 {
131 
132 	/* don't reset the timer when/if recursing */
133 	if (lock_prof_enable && lo->lo_profile_obj.lpo_acqtime == 0) {
134 #ifdef LOCK_PROFILING_FAST
135                if (contested == 0)
136                        return;
137 #endif
138 	       _lock_profile_obtain_lock_success(lo, contested, waittime, file, line);
139 	}
140 }
141 static inline void lock_profile_release_lock(struct lock_object *lo)
142 {
143 	struct lock_profile_object *l = &lo->lo_profile_obj;
144 
145 	if (l->lpo_acqtime)
146 		_lock_profile_release_lock(lo);
147 }
148 
149 #endif /* _KERNEL */
150 
151 #else /* !LOCK_PROFILING */
152 
153 #ifdef _KERNEL
154 static inline void lock_profile_update_wait(struct lock_object *lo, uint64_t waitstart) {;}
155 static inline void lock_profile_update_contest_locking(struct lock_object *lo, int contested) {;}
156 static inline void lock_profile_release_lock(struct lock_object *lo) {;}
157 static inline void lock_profile_obtain_lock_failed(struct lock_object *lo, int *contested, uint64_t *waittime) {;}
158 static inline void lock_profile_obtain_lock_success(struct lock_object *lo, int contested, uint64_t waittime,
159 						    const char *file, int line) {;}
160 static inline void lock_profile_object_destroy(struct lock_object *lo) {;}
161 static inline void lock_profile_object_init(struct lock_object *lo, struct lock_class *class, const char *name) {;}
162 
163 #endif /* _KERNEL */
164 
165 #endif  /* !LOCK_PROFILING */
166 
167 #endif /* _SYS_LOCK_PROFILE_H_ */
168