Commit | Line | Data |
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7514523f | 1 | /* |
3d084699 | 2 | * ltt-ring-buffer-client.h |
7514523f MD |
3 | * |
4 | * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
5 | * | |
3d084699 | 6 | * LTTng lib ring buffer client template. |
7514523f MD |
7 | * |
8 | * Dual LGPL v2.1/GPL v2 license. | |
9 | */ | |
10 | ||
11 | #include <linux/module.h> | |
12 | #include "ltt-tracer.h" | |
13 | ||
14 | struct ring_buffer_priv { | |
15 | struct dentry *dentry; | |
16 | } | |
17 | ||
18 | struct channel_priv { | |
19 | struct ltt_trace *trace; | |
20 | struct ring_buffer_priv *buf; | |
21 | }; | |
22 | ||
23 | static const struct lib_ring_buffer_config client_config; | |
24 | ||
25 | static u64 client_ring_buffer_clock_read(struct channel *chan) | |
26 | { | |
27 | return lib_ring_buffer_clock_read(chan); | |
28 | } | |
29 | ||
1e2015dc | 30 | static |
7514523f MD |
31 | size_t client_record_header_size(const struct lib_ring_buffer_config *config, |
32 | struct channel *chan, size_t offset, | |
33 | size_t data_size, | |
34 | size_t *pre_header_padding, | |
35 | unsigned int rflags, | |
36 | struct lib_ring_buffer_ctx *ctx) | |
37 | { | |
38 | return record_header_size(config, chan, offset, data_size, | |
39 | pre_header_padding, rflags, ctx); | |
40 | } | |
41 | ||
42 | /** | |
43 | * client_subbuffer_header_size - called on buffer-switch to a new sub-buffer | |
44 | * | |
45 | * Return header size without padding after the structure. Don't use packed | |
46 | * structure because gcc generates inefficient code on some architectures | |
47 | * (powerpc, mips..) | |
48 | */ | |
49 | static size_t client_subbuffer_header_size(void) | |
50 | { | |
51 | return offsetof(struct subbuffer_header, header_end); | |
52 | } | |
53 | ||
54 | static void client_buffer_begin(struct lib_ring_buffer *buf, u64 tsc, | |
55 | unsigned int subbuf_idx) | |
56 | { | |
57 | struct channel *chan = buf->backend.chan; | |
58 | struct subbuffer_header *header = | |
59 | (struct subbuffer_header *) | |
60 | lib_ring_buffer_offset_address(&buf->backend, | |
61 | subbuf_idx * chan->backend.subbuf_size); | |
62 | ||
63 | header->cycle_count_begin = tsc; | |
64 | header->data_size = 0xFFFFFFFF; /* for debugging */ | |
65 | write_trace_header(chan->backend.priv, header); | |
66 | } | |
67 | ||
68 | /* | |
69 | * offset is assumed to never be 0 here : never deliver a completely empty | |
70 | * subbuffer. data_size is between 1 and subbuf_size. | |
71 | */ | |
72 | static void client_buffer_end(struct lib_ring_buffer *buf, u64 tsc, | |
73 | unsigned int subbuf_idx, unsigned long data_size) | |
74 | { | |
75 | struct channel *chan = buf->backend.chan; | |
76 | struct subbuffer_header *header = | |
77 | (struct subbuffer_header *) | |
78 | lib_ring_buffer_offset_address(&buf->backend, | |
79 | subbuf_idx * chan->backend.subbuf_size); | |
80 | unsigned long records_lost = 0; | |
81 | ||
82 | header->data_size = data_size; | |
83 | header->subbuf_size = PAGE_ALIGN(data_size); | |
84 | header->cycle_count_end = tsc; | |
85 | records_lost += lib_ring_buffer_get_records_lost_full(&client_config, buf); | |
86 | records_lost += lib_ring_buffer_get_records_lost_wrap(&client_config, buf); | |
87 | records_lost += lib_ring_buffer_get_records_lost_big(&client_config, buf); | |
88 | header->events_lost = records_lost; | |
89 | header->subbuf_corrupt = 0; /* deprecated */ | |
90 | } | |
91 | ||
92 | static int client_buffer_create(struct lib_ring_buffer *buf, void *priv, | |
93 | int cpu, const char *name) | |
94 | { | |
95 | struct channel_priv *chan_priv = priv; | |
96 | struct ring_buffer_priv *buf_priv; | |
97 | struct dentry *trace_dentry; | |
98 | char *tmpname; | |
99 | int ret = 0; | |
100 | ||
101 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) | |
102 | buf_priv = per_cpu_ptr(chan_priv->buf, cpu); | |
103 | else | |
104 | buf_priv = chan_priv->buf; | |
105 | ||
106 | tmpname = kzalloc(NAME_MAX + 1, GFP_KERNEL); | |
107 | if (!tmpname) { | |
108 | ret = -ENOMEM; | |
109 | goto end; | |
110 | } | |
111 | ||
112 | snprintf(tmpname, NAME_MAX, "%s%s_%d", | |
3d084699 | 113 | (client_config.mode == RING_BUFFER_OVERWRITE) ? "flight-" : "", |
7514523f MD |
114 | name, cpu); |
115 | ||
116 | trace_dentry = chan_priv->trace->dentry.trace_root; | |
117 | buf_priv->dentry = debugfs_create_file(tmpname, S_IRUSR, trace_dentry, | |
118 | buf, | |
119 | &lib_ring_buffer_file_operations); | |
120 | if (!buf_priv->dentry) { | |
121 | ret = -ENOMEM; | |
122 | goto free_name; | |
123 | } | |
124 | free_name: | |
125 | kfree(tmpname); | |
126 | end: | |
127 | return ret; | |
128 | } | |
129 | ||
130 | static void client_buffer_finalize(struct lib_ring_buffer *buf, void *priv, int cpu) | |
131 | { | |
132 | struct channel_priv *chan_priv = priv; | |
133 | struct lib_ring_buffer_priv *buf_priv; | |
134 | ||
135 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) | |
136 | buf_priv = per_cpu_ptr(chan_priv->buf, cpu); | |
137 | else | |
138 | buf_priv = chan_priv->buf; | |
139 | ||
140 | debugfs_remove(buf_priv->dentry); | |
141 | } | |
142 | ||
143 | static const struct lib_ring_buffer_config client_config = { | |
144 | .cb.ring_buffer_clock_read = client_ring_buffer_clock_read, | |
145 | .cb.record_header_size = client_record_header_size, | |
146 | .cb.subbuffer_header_size = client_subbuffer_header_size, | |
147 | .cb.buffer_begin = client_buffer_begin, | |
148 | .cb.buffer_end = client_buffer_end, | |
149 | .cb.buffer_create = client_buffer_create, | |
150 | .cb.buffer_finalize = client_buffer_finalize, | |
151 | ||
152 | .tsc_bits = 32, | |
153 | .alloc = RING_BUFFER_ALLOC_PER_CPU, | |
154 | .sync = RING_BUFFER_SYNC_PER_CPU, | |
3d084699 | 155 | .mode = RING_BUFFER_MODE_TEMPLATE, |
7514523f MD |
156 | #ifdef RING_BUFFER_ALIGN |
157 | .align = RING_BUFFER_NATURAL, | |
158 | #else | |
159 | .align = RING_BUFFER_PACKED, | |
160 | #endif | |
161 | .backend = RING_BUFFER_PAGE, | |
162 | .output = RING_BUFFER_SPLICE, | |
163 | .oops = RING_BUFFER_OOPS_CONSISTENCY, | |
164 | .ipi = RING_BUFFER_IPI_BARRIER, | |
165 | .wakeup = RING_BUFFER_WAKEUP_BY_TIMER, | |
166 | }; | |
167 | ||
1e2015dc | 168 | static |
7514523f MD |
169 | struct channel *ltt_channel_create(const char *name, struct ltt_trace *trace, |
170 | void *buf_addr, | |
171 | size_t subbuf_size, size_t num_subbuf, | |
172 | unsigned int switch_timer_interval, | |
173 | unsigned int read_timer_interval) | |
174 | { | |
175 | struct channel *chan; | |
176 | struct chan_priv *chan_priv; | |
177 | ||
178 | chan_priv = kzalloc(sizeof(struct chan_priv), GFP_KERNEL); | |
179 | if (!chan_priv) | |
180 | return NULL; | |
181 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) { | |
182 | chan_priv->buf = alloc_percpu(struct lib_ring_buffer_priv); | |
183 | memset(chan_priv->buf, 0, sizeof(*chan_priv->buf)); | |
184 | } else | |
185 | chan_priv->buf = kzalloc(sizeof(*chan_priv->buf), GFP_KERNEL) | |
186 | if (!channel_priv->buf) | |
187 | goto free_chan_priv; | |
188 | chan_priv->trace = trace; | |
189 | chan = channel_create(&client_config, name, chan_priv, buf_addr, | |
190 | subbuf_size, num_subbuf, switch_timer_interval, | |
191 | read_timer_interval); | |
192 | if (!chan) | |
193 | goto free_buf_priv; | |
194 | return chan; | |
195 | ||
196 | free_buf_priv: | |
197 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) | |
198 | free_percpu(chan_priv->buf); | |
199 | else | |
200 | kfree(chan_priv->buf); | |
201 | free_chan_priv: | |
202 | kfree(chan_priv); | |
203 | return NULL; | |
204 | } | |
205 | ||
1e2015dc | 206 | static |
7514523f MD |
207 | void ltt_channel_destroy(struct channel *chan) |
208 | { | |
209 | struct chan_priv *chan_priv = channel_get_private(chan); | |
210 | ||
211 | channel_destroy(chan); | |
212 | if (client_config.alloc == RING_BUFFER_ALLOC_PER_CPU) | |
213 | free_percpu(chan_priv->buf); | |
214 | else | |
215 | kfree(chan_priv->buf); | |
216 | kfree(chan_priv); | |
217 | } | |
218 | ||
219 | static void ltt_relay_remove_dirs(struct ltt_trace *trace) | |
220 | { | |
7514523f MD |
221 | debugfs_remove(trace->dentry.trace_root); |
222 | } | |
223 | ||
224 | static int ltt_relay_create_dirs(struct ltt_trace *new_trace) | |
225 | { | |
226 | struct dentry *ltt_root_dentry; | |
227 | int ret; | |
228 | ||
229 | ltt_root_dentry = get_ltt_root(); | |
230 | if (!ltt_root_dentry) | |
231 | return ENOENT; | |
232 | ||
233 | new_trace->dentry.trace_root = debugfs_create_dir(new_trace->trace_name, | |
234 | ltt_root_dentry); | |
235 | put_ltt_root(); | |
236 | if (new_trace->dentry.trace_root == NULL) { | |
237 | printk(KERN_ERR "LTT : Trace directory name %s already taken\n", | |
238 | new_trace->trace_name); | |
239 | return EEXIST; | |
240 | } | |
7514523f MD |
241 | return 0; |
242 | } | |
1e2015dc | 243 | |
7514523f | 244 | static struct ltt_transport ltt_relay_transport = { |
3d084699 | 245 | .name = "relay-" RING_BUFFER_MODE_TEMPLATE_STRING, |
7514523f MD |
246 | .owner = THIS_MODULE, |
247 | .ops = { | |
248 | .create_dirs = ltt_relay_create_dirs, | |
249 | .remove_dirs = ltt_relay_remove_dirs, | |
1e2015dc MD |
250 | .create_channel = ltt_channel_create, |
251 | .destroy_channel = ltt_channel_destroy, | |
7514523f MD |
252 | }, |
253 | }; | |
254 | ||
3d084699 | 255 | static int __init ltt_ring_buffer_client_init(void) |
7514523f MD |
256 | { |
257 | printk(KERN_INFO "LTT : ltt ring buffer client init\n"); | |
258 | ltt_transport_register(<t_relay_transport); | |
259 | return 0; | |
260 | } | |
261 | ||
3d084699 | 262 | static void __exit ltt_ring_buffer_client_exit(void) |
7514523f MD |
263 | { |
264 | printk(KERN_INFO "LTT : ltt ring buffer client exit\n"); | |
265 | ltt_transport_unregister(<t_relay_transport); | |
266 | } | |
267 | ||
268 | MODULE_LICENSE("GPL and additional rights"); | |
269 | MODULE_AUTHOR("Mathieu Desnoyers"); | |
3d084699 MD |
270 | MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING |
271 | " client"); |