1 // SPDX-License-Identifier: GPL-2.0
2 #ifndef PERF_LOCK_CONTENTION_H
3 #define PERF_LOCK_CONTENTION_H
4 
5 #include <linux/list.h>
6 #include <linux/rbtree.h>
7 
8 struct lock_filter {
9 	int			nr_types;
10 	int			nr_addrs;
11 	int			nr_syms;
12 	unsigned int		*types;
13 	unsigned long		*addrs;
14 	char			**syms;
15 };
16 
17 struct lock_stat {
18 	struct hlist_node	hash_entry;
19 	struct rb_node		rb;		/* used for sorting */
20 
21 	u64			addr;		/* address of lockdep_map, used as ID */
22 	char			*name;		/* for strcpy(), we cannot use const */
23 	u64			*callstack;
24 
25 	unsigned int		nr_acquire;
26 	unsigned int		nr_acquired;
27 	unsigned int		nr_contended;
28 	unsigned int		nr_release;
29 
30 	union {
31 		unsigned int	nr_readlock;
32 		unsigned int	flags;
33 	};
34 	unsigned int		nr_trylock;
35 
36 	/* these times are in nano sec. */
37 	u64                     avg_wait_time;
38 	u64			wait_time_total;
39 	u64			wait_time_min;
40 	u64			wait_time_max;
41 
42 	int			broken; /* flag of blacklist */
43 	int			combined;
44 };
45 
46 /*
47  * States of lock_seq_stat
48  *
49  * UNINITIALIZED is required for detecting first event of acquire.
50  * As the nature of lock events, there is no guarantee
51  * that the first event for the locks are acquire,
52  * it can be acquired, contended or release.
53  */
54 #define SEQ_STATE_UNINITIALIZED      0	       /* initial state */
55 #define SEQ_STATE_RELEASED	1
56 #define SEQ_STATE_ACQUIRING	2
57 #define SEQ_STATE_ACQUIRED	3
58 #define SEQ_STATE_READ_ACQUIRED	4
59 #define SEQ_STATE_CONTENDED	5
60 
61 /*
62  * MAX_LOCK_DEPTH
63  * Imported from include/linux/sched.h.
64  * Should this be synchronized?
65  */
66 #define MAX_LOCK_DEPTH 48
67 
68 struct lock_stat *lock_stat_find(u64 addr);
69 struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);
70 
71 bool match_callstack_filter(struct machine *machine, u64 *callstack);
72 
73 /*
74  * struct lock_seq_stat:
75  * Place to put on state of one lock sequence
76  * 1) acquire -> acquired -> release
77  * 2) acquire -> contended -> acquired -> release
78  * 3) acquire (with read or try) -> release
79  * 4) Are there other patterns?
80  */
81 struct lock_seq_stat {
82 	struct list_head        list;
83 	int			state;
84 	u64			prev_event_time;
85 	u64                     addr;
86 
87 	int                     read_count;
88 };
89 
90 struct thread_stat {
91 	struct rb_node		rb;
92 
93 	u32                     tid;
94 	struct list_head        seq_list;
95 };
96 
97 /*
98  * CONTENTION_STACK_DEPTH
99  * Number of stack trace entries to find callers
100  */
101 #define CONTENTION_STACK_DEPTH  8
102 
103 /*
104  * CONTENTION_STACK_SKIP
105  * Number of stack trace entries to skip when finding callers.
106  * The first few entries belong to the locking implementation itself.
107  */
108 #define CONTENTION_STACK_SKIP  4
109 
110 /*
111  * flags for lock:contention_begin
112  * Imported from include/trace/events/lock.h.
113  */
114 #define LCB_F_SPIN	(1U << 0)
115 #define LCB_F_READ	(1U << 1)
116 #define LCB_F_WRITE	(1U << 2)
117 #define LCB_F_RT	(1U << 3)
118 #define LCB_F_PERCPU	(1U << 4)
119 #define LCB_F_MUTEX	(1U << 5)
120 
121 struct evlist;
122 struct machine;
123 struct target;
124 
125 struct lock_contention {
126 	struct evlist *evlist;
127 	struct target *target;
128 	struct machine *machine;
129 	struct hlist_head *result;
130 	struct lock_filter *filters;
131 	unsigned long map_nr_entries;
132 	int lost;
133 	int max_stack;
134 	int stack_skip;
135 	int aggr_mode;
136 	int owner;
137 	bool save_callstack;
138 };
139 
140 #ifdef HAVE_BPF_SKEL
141 
142 int lock_contention_prepare(struct lock_contention *con);
143 int lock_contention_start(void);
144 int lock_contention_stop(void);
145 int lock_contention_read(struct lock_contention *con);
146 int lock_contention_finish(void);
147 
148 #else  /* !HAVE_BPF_SKEL */
149 
150 static inline int lock_contention_prepare(struct lock_contention *con __maybe_unused)
151 {
152 	return 0;
153 }
154 
155 static inline int lock_contention_start(void) { return 0; }
156 static inline int lock_contention_stop(void) { return 0; }
157 static inline int lock_contention_finish(void) { return 0; }
158 
159 static inline int lock_contention_read(struct lock_contention *con __maybe_unused)
160 {
161 	return 0;
162 }
163 
164 #endif  /* HAVE_BPF_SKEL */
165 
166 #endif  /* PERF_LOCK_CONTENTION_H */
167