xref: /netbsd/sys/dev/lockstat.h (revision 07ba99ac)
1 /*	$NetBSD: lockstat.h,v 1.15 2022/02/27 14:16:12 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef _SYS_LOCKSTAT_H_
33 #define _SYS_LOCKSTAT_H_
34 
35 #ifdef _KERNEL_OPT
36 #include "opt_dtrace.h"
37 #include <lockstat.h>
38 #endif
39 
40 #include <sys/types.h>
41 
42 #include <sys/ioccom.h>
43 #include <sys/lock.h>
44 #include <sys/queue.h>
45 #include <sys/time.h>
46 
47 #if defined(_KERNEL) && defined(__HAVE_CPU_COUNTER)
48 #include <machine/cpu_counter.h>
49 #endif
50 
51 /*
52  * Interface version.  The interface is not designed to provide
53  * compatibility across NetBSD releases.
54  */
55 
56 #define	IOC_LOCKSTAT_GVERSION	_IOR('L', 0, int)
57 
58 #define	LS_VERSION	5
59 
60 /*
61  * Enable request.  We can limit tracing by the call site and by
62  * the lock.  We also specify the number of event buffers to
63  * allocate up front, and what kind of events to track.
64  */
65 
66 #define	IOC_LOCKSTAT_ENABLE	_IOW('L', 1, lsenable_t)
67 
68 #define LE_CALLSITE	0x01		/* track call sites */
69 #define	LE_ONE_CALLSITE	0x02		/* specific call site */
70 #define	LE_ONE_LOCK	0x04		/* specific lock */
71 #define LE_LOCK		0x08		/* track locks */
72 
73 typedef struct lsenable {
74 	uintptr_t	le_csstart;	/* callsite start */
75 	uintptr_t	le_csend;	/* callsite end */
76 	uintptr_t	le_lockstart;	/* lock address start */
77 	uintptr_t	le_lockend;	/* lock address end */
78 	uintptr_t	le_nbufs;	/* buffers to allocate, 0 = default */
79 	u_int		le_flags;	/* request flags */
80 	u_int		le_mask;	/* event mask (LB_*) */
81 } lsenable_t;
82 
83 /*
84  * Disable request.
85  */
86 
87 #define	IOC_LOCKSTAT_DISABLE	_IOR('L', 2, lsdisable_t)
88 
89 typedef struct lsdisable {
90 	size_t		ld_size;	/* buffer space allocated */
91 	struct timespec	ld_time;	/* time spent enabled */
92 	uint64_t	ld_freq[64];	/* counter HZ by CPU number */
93 } lsdisable_t;
94 
95 /*
96  * Event buffers returned from reading from the devices.
97  */
98 
99 /*
100  * Event types, for lockstat_event().  Stored in lb_flags but should be
101  * meaningless to the consumer, also provided with the enable request
102  * in le_mask.
103  */
104 #define	LB_SPIN			0x00000001
105 #define	LB_SLEEP1		0x00000002
106 #define	LB_SLEEP2		0x00000003
107 #define	LB_NEVENT		0x00000003
108 #define	LB_EVENT_MASK		0x000000ff
109 
110 /*
111  * Lock types, the only part of lb_flags that should be inspected.  Also
112  * provided with the enable request in le_mask.
113  */
114 #define	LB_ADAPTIVE_MUTEX	0x00000100
115 #define	LB_SPIN_MUTEX		0x00000200
116 #define	LB_RWLOCK		0x00000300
117 #define	LB_NOPREEMPT		0x00000400
118 #define	LB_KERNEL_LOCK		0x00000500
119 #define	LB_MISC			0x00000600
120 #define	LB_NLOCK		0x00000600
121 #define	LB_LOCK_MASK		0x0000ff00
122 #define	LB_LOCK_SHIFT		8
123 
124 #define	LB_DTRACE		0x00010000
125 
126 typedef struct lsbuf {
127 	union {
128 		LIST_ENTRY(lsbuf) list;
129 		SLIST_ENTRY(lsbuf) slist;
130 		TAILQ_ENTRY(lsbuf) tailq;
131 	} lb_chain;
132 	uintptr_t	lb_lock;		/* lock address */
133 	uintptr_t	lb_callsite;		/* call site */
134 	uint64_t	lb_times[LB_NEVENT];	/* cumulative times */
135 	uint32_t	lb_counts[LB_NEVENT];	/* count of events */
136 	uint16_t	lb_flags;		/* lock type */
137 	uint16_t	lb_cpu;			/* CPU number */
138 } lsbuf_t;
139 
140 /*
141  * Tracing stubs used by lock providers.
142  */
143 
144 #if defined(_KERNEL) && defined(__HAVE_CPU_COUNTER) && NLOCKSTAT > 0
145 
146 #define	LOCKSTAT_EVENT(flag, lock, type, count, time)			\
147 do {									\
148 	if (__predict_false(flag))					\
149 		lockstat_event((uintptr_t)(lock),			\
150 		    (uintptr_t)__builtin_return_address(0),		\
151 		    (type), (count), (time));				\
152 } while (/* CONSTCOND */ 0);
153 
154 #define	LOCKSTAT_EVENT_RA(flag, lock, type, count, time, ra)		\
155 do {									\
156 	if (__predict_false(flag))					\
157 		lockstat_event((uintptr_t)(lock), (uintptr_t)ra,	\
158 		    (type), (count), (time));				\
159 } while (/* CONSTCOND */ 0);
160 
161 #define	LOCKSTAT_TIMER(name)	uint64_t name = 0
162 #define	LOCKSTAT_COUNTER(name)	uint64_t name = 0
163 #define	LOCKSTAT_FLAG(name)	int name
164 #define	LOCKSTAT_ENTER(name)	name = atomic_load_relaxed(&lockstat_enabled)
165 #define	LOCKSTAT_EXIT(name)
166 
167 #define	LOCKSTAT_START_TIMER(flag, name)				\
168 do {									\
169 	if (__predict_false(flag))					\
170 		(name) -= cpu_counter();				\
171 } while (/* CONSTCOND */ 0)
172 
173 #define	LOCKSTAT_STOP_TIMER(flag, name)					\
174 do {									\
175 	if (__predict_false(flag))					\
176 		(name) += cpu_counter();				\
177 } while (/* CONSTCOND */ 0)
178 
179 #define	LOCKSTAT_COUNT(name, inc)					\
180 do {									\
181 	(name) += (inc);						\
182 } while (/* CONSTCOND */ 0)
183 
184 void	lockstat_event(uintptr_t, uintptr_t, u_int, u_int, uint64_t);
185 
186 #else
187 
188 #define	LOCKSTAT_FLAG(name)					/* nothing */
189 #define	LOCKSTAT_ENTER(name)					/* nothing */
190 #define	LOCKSTAT_EXIT(name)					/* nothing */
191 #define	LOCKSTAT_EVENT(flag, lock, type, count, time)		/* nothing */
192 #define	LOCKSTAT_EVENT_RA(flag, lock, type, count, time, ra)	/* nothing */
193 #define	LOCKSTAT_TIMER(void)					/* nothing */
194 #define	LOCKSTAT_COUNTER(void)					/* nothing */
195 #define	LOCKSTAT_START_TIMER(flag, void)			/* nothing */
196 #define	LOCKSTAT_STOP_TIMER(flag, void)				/* nothing */
197 #define	LOCKSTAT_COUNT(name, int)				/* nothing */
198 
199 #endif
200 
201 #ifdef KDTRACE_HOOKS
202 extern volatile u_int lockstat_dtrace_enabled;
203 #define KDTRACE_LOCKSTAT_ENABLED lockstat_dtrace_enabled
204 #define LS_COMPRESS(f) \
205     ((((f) & 0x3) | (((f) & 0x700) >> 6)) & (LS_NPROBES - 1))
206 #define	LS_NPROBES	0x20	/* 5 bits */
207 
208 extern uint32_t	lockstat_probemap[];
209 extern void	(*lockstat_probe_func)(uint32_t, uintptr_t, uintptr_t,
210     uintptr_t, uintptr_t, uintptr_t);
211 
212 void		lockstat_probe_stub(uint32_t, uintptr_t, uintptr_t,
213     uintptr_t, uintptr_t, uintptr_t);
214 #else
215 #define KDTRACE_LOCKSTAT_ENABLED 0
216 #endif
217 
218 #if defined(_KERNEL) && NLOCKSTAT > 0
219 extern __cpu_simple_lock_t lockstat_enabled_lock;
220 extern volatile u_int	lockstat_enabled;
221 extern volatile u_int	lockstat_dev_enabled;
222 
223 #define LOCKSTAT_ENABLED_UPDATE_BEGIN() do				    \
224 {									    \
225 	__cpu_simple_lock(&lockstat_enabled_lock);			    \
226 } while (/*CONSTCOND*/0)
227 
228 #define LOCKSTAT_ENABLED_UPDATE_END() do				    \
229 {									    \
230 	atomic_store_relaxed(&lockstat_enabled,				    \
231 	    lockstat_dev_enabled | KDTRACE_LOCKSTAT_ENABLED);		    \
232 	__cpu_simple_unlock(&lockstat_enabled_lock);			    \
233 } while (/*CONSTCOND*/0)
234 
235 #endif
236 
237 #endif	/* _SYS_LOCKSTAT_H_ */
238