2 * lttng-ring-buffer-client.h
4 * LTTng lib ring buffer client template.
6 * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; only
11 * version 2.1 of the License.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include <linux/module.h>
24 #include <linux/types.h>
25 #include <wrapper/vmalloc.h> /* for wrapper_vmalloc_sync_all() */
26 #include <lttng-events.h>
27 #include <lttng-tracer.h>
29 static struct lttng_transport lttng_relay_transport
;
31 struct metadata_packet_header
{
32 uint32_t magic
; /* 0x75D11D57 */
33 uint8_t uuid
[16]; /* Unique Universal Identifier */
34 uint32_t checksum
; /* 0 if unused */
35 uint32_t content_size
; /* in bits */
36 uint32_t packet_size
; /* in bits */
37 uint8_t compression_scheme
; /* 0 if unused */
38 uint8_t encryption_scheme
; /* 0 if unused */
39 uint8_t checksum_scheme
; /* 0 if unused */
40 uint8_t major
; /* CTF spec major version number */
41 uint8_t minor
; /* CTF spec minor version number */
42 uint8_t header_end
[0];
45 struct metadata_record_header
{
46 uint8_t header_end
[0]; /* End of header */
49 static const struct lib_ring_buffer_config client_config
;
52 u64
lib_ring_buffer_clock_read(struct channel
*chan
)
58 size_t record_header_size(const struct lib_ring_buffer_config
*config
,
59 struct channel
*chan
, size_t offset
,
60 size_t *pre_header_padding
,
61 struct lib_ring_buffer_ctx
*ctx
,
67 #include <wrapper/ringbuffer/api.h>
69 static u64
client_ring_buffer_clock_read(struct channel
*chan
)
75 size_t client_record_header_size(const struct lib_ring_buffer_config
*config
,
76 struct channel
*chan
, size_t offset
,
77 size_t *pre_header_padding
,
78 struct lib_ring_buffer_ctx
*ctx
,
85 * client_packet_header_size - called on buffer-switch to a new sub-buffer
87 * Return header size without padding after the structure. Don't use packed
88 * structure because gcc generates inefficient code on some architectures
91 static size_t client_packet_header_size(void)
93 return offsetof(struct metadata_packet_header
, header_end
);
96 static void client_buffer_begin(struct lib_ring_buffer
*buf
, u64 tsc
,
97 unsigned int subbuf_idx
)
99 struct channel
*chan
= buf
->backend
.chan
;
100 struct metadata_packet_header
*header
=
101 (struct metadata_packet_header
*)
102 lib_ring_buffer_offset_address(&buf
->backend
,
103 subbuf_idx
* chan
->backend
.subbuf_size
);
104 struct lttng_metadata_cache
*metadata_cache
=
105 channel_get_private(chan
);
107 header
->magic
= TSDL_MAGIC_NUMBER
;
108 memcpy(header
->uuid
, metadata_cache
->uuid
.b
,
109 sizeof(metadata_cache
->uuid
));
110 header
->checksum
= 0; /* 0 if unused */
111 header
->content_size
= 0xFFFFFFFF; /* in bits, for debugging */
112 header
->packet_size
= 0xFFFFFFFF; /* in bits, for debugging */
113 header
->compression_scheme
= 0; /* 0 if unused */
114 header
->encryption_scheme
= 0; /* 0 if unused */
115 header
->checksum_scheme
= 0; /* 0 if unused */
116 header
->major
= CTF_SPEC_MAJOR
;
117 header
->minor
= CTF_SPEC_MINOR
;
121 * offset is assumed to never be 0 here : never deliver a completely empty
122 * subbuffer. data_size is between 1 and subbuf_size.
124 static void client_buffer_end(struct lib_ring_buffer
*buf
, u64 tsc
,
125 unsigned int subbuf_idx
, unsigned long data_size
)
127 struct channel
*chan
= buf
->backend
.chan
;
128 struct metadata_packet_header
*header
=
129 (struct metadata_packet_header
*)
130 lib_ring_buffer_offset_address(&buf
->backend
,
131 subbuf_idx
* chan
->backend
.subbuf_size
);
132 unsigned long records_lost
= 0;
134 header
->content_size
= data_size
* CHAR_BIT
; /* in bits */
135 header
->packet_size
= PAGE_ALIGN(data_size
) * CHAR_BIT
; /* in bits */
137 * We do not care about the records lost count, because the metadata
138 * channel waits and retry.
140 (void) lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
141 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
142 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
143 WARN_ON_ONCE(records_lost
!= 0);
146 static int client_buffer_create(struct lib_ring_buffer
*buf
, void *priv
,
147 int cpu
, const char *name
)
152 static void client_buffer_finalize(struct lib_ring_buffer
*buf
, void *priv
, int cpu
)
156 static int client_timestamp_begin(const struct lib_ring_buffer_config
*config
,
157 struct lib_ring_buffer
*buf
, uint64_t *timestamp_begin
)
162 static int client_timestamp_end(const struct lib_ring_buffer_config
*config
,
163 struct lib_ring_buffer
*bufb
,
164 uint64_t *timestamp_end
)
169 static int client_events_discarded(const struct lib_ring_buffer_config
*config
,
170 struct lib_ring_buffer
*bufb
,
171 uint64_t *events_discarded
)
176 static int client_current_timestamp(const struct lib_ring_buffer_config
*config
,
177 struct lib_ring_buffer
*bufb
,
183 static int client_content_size(const struct lib_ring_buffer_config
*config
,
184 struct lib_ring_buffer
*bufb
,
185 uint64_t *content_size
)
190 static int client_packet_size(const struct lib_ring_buffer_config
*config
,
191 struct lib_ring_buffer
*bufb
,
192 uint64_t *packet_size
)
197 static int client_stream_id(const struct lib_ring_buffer_config
*config
,
198 struct lib_ring_buffer
*bufb
,
204 static int client_sequence_number(const struct lib_ring_buffer_config
*config
,
205 struct lib_ring_buffer
*bufb
,
212 int client_instance_id(const struct lib_ring_buffer_config
*config
,
213 struct lib_ring_buffer
*bufb
,
219 static const struct lib_ring_buffer_config client_config
= {
220 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
221 .cb
.record_header_size
= client_record_header_size
,
222 .cb
.subbuffer_header_size
= client_packet_header_size
,
223 .cb
.buffer_begin
= client_buffer_begin
,
224 .cb
.buffer_end
= client_buffer_end
,
225 .cb
.buffer_create
= client_buffer_create
,
226 .cb
.buffer_finalize
= client_buffer_finalize
,
229 .alloc
= RING_BUFFER_ALLOC_GLOBAL
,
230 .sync
= RING_BUFFER_SYNC_GLOBAL
,
231 .mode
= RING_BUFFER_MODE_TEMPLATE
,
232 .backend
= RING_BUFFER_PAGE
,
233 .output
= RING_BUFFER_OUTPUT_TEMPLATE
,
234 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
235 .ipi
= RING_BUFFER_IPI_BARRIER
,
236 .wakeup
= RING_BUFFER_WAKEUP_BY_TIMER
,
240 void release_priv_ops(void *priv_ops
)
242 module_put(THIS_MODULE
);
246 void lttng_channel_destroy(struct channel
*chan
)
248 channel_destroy(chan
);
252 struct channel
*_channel_create(const char *name
,
253 struct lttng_channel
*lttng_chan
, void *buf_addr
,
254 size_t subbuf_size
, size_t num_subbuf
,
255 unsigned int switch_timer_interval
,
256 unsigned int read_timer_interval
)
258 struct channel
*chan
;
260 chan
= channel_create(&client_config
, name
,
261 lttng_chan
->session
->metadata_cache
, buf_addr
,
262 subbuf_size
, num_subbuf
, switch_timer_interval
,
263 read_timer_interval
);
266 * Ensure this module is not unloaded before we finish
267 * using lttng_relay_transport.ops.
269 if (!try_module_get(THIS_MODULE
)) {
270 printk(KERN_WARNING
"LTT : Can't lock transport module.\n");
273 chan
->backend
.priv_ops
= <tng_relay_transport
.ops
;
274 chan
->backend
.release_priv_ops
= release_priv_ops
;
279 lttng_channel_destroy(chan
);
284 struct lib_ring_buffer
*lttng_buffer_read_open(struct channel
*chan
)
286 struct lib_ring_buffer
*buf
;
288 buf
= channel_get_ring_buffer(&client_config
, chan
, 0);
289 if (!lib_ring_buffer_open_read(buf
))
295 int lttng_buffer_has_read_closed_stream(struct channel
*chan
)
297 struct lib_ring_buffer
*buf
;
300 for_each_channel_cpu(cpu
, chan
) {
301 buf
= channel_get_ring_buffer(&client_config
, chan
, cpu
);
302 if (!atomic_long_read(&buf
->active_readers
))
309 void lttng_buffer_read_close(struct lib_ring_buffer
*buf
)
311 lib_ring_buffer_release_read(buf
);
315 int lttng_event_reserve(struct lib_ring_buffer_ctx
*ctx
, uint32_t event_id
)
319 ret
= lib_ring_buffer_reserve(&client_config
, ctx
, NULL
);
322 lib_ring_buffer_backend_get_pages(&client_config
, ctx
,
323 &ctx
->backend_pages
);
329 void lttng_event_commit(struct lib_ring_buffer_ctx
*ctx
)
331 lib_ring_buffer_commit(&client_config
, ctx
);
335 void lttng_event_write(struct lib_ring_buffer_ctx
*ctx
, const void *src
,
338 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
342 void lttng_event_write_from_user(struct lib_ring_buffer_ctx
*ctx
,
343 const void __user
*src
, size_t len
)
345 lib_ring_buffer_copy_from_user_inatomic(&client_config
, ctx
, src
, len
);
349 void lttng_event_memset(struct lib_ring_buffer_ctx
*ctx
,
352 lib_ring_buffer_memset(&client_config
, ctx
, c
, len
);
356 void lttng_event_strcpy(struct lib_ring_buffer_ctx
*ctx
, const char *src
,
359 lib_ring_buffer_strcpy(&client_config
, ctx
, src
, len
, '#');
363 size_t lttng_packet_avail_size(struct channel
*chan
)
366 unsigned long o_begin
;
367 struct lib_ring_buffer
*buf
;
369 buf
= chan
->backend
.buf
; /* Only for global buffer ! */
370 o_begin
= v_read(&client_config
, &buf
->offset
);
371 if (subbuf_offset(o_begin
, chan
) != 0) {
372 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
);
374 return chan
->backend
.subbuf_size
- subbuf_offset(o_begin
, chan
)
375 - sizeof(struct metadata_packet_header
);
380 wait_queue_head_t
*lttng_get_writer_buf_wait_queue(struct channel
*chan
, int cpu
)
382 struct lib_ring_buffer
*buf
= channel_get_ring_buffer(&client_config
,
384 return &buf
->write_wait
;
388 wait_queue_head_t
*lttng_get_hp_wait_queue(struct channel
*chan
)
390 return &chan
->hp_wait
;
394 int lttng_is_finalized(struct channel
*chan
)
396 return lib_ring_buffer_channel_is_finalized(chan
);
400 int lttng_is_disabled(struct channel
*chan
)
402 return lib_ring_buffer_channel_is_disabled(chan
);
405 static struct lttng_transport lttng_relay_transport
= {
406 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
,
407 .owner
= THIS_MODULE
,
409 .channel_create
= _channel_create
,
410 .channel_destroy
= lttng_channel_destroy
,
411 .buffer_read_open
= lttng_buffer_read_open
,
412 .buffer_has_read_closed_stream
=
413 lttng_buffer_has_read_closed_stream
,
414 .buffer_read_close
= lttng_buffer_read_close
,
415 .event_reserve
= lttng_event_reserve
,
416 .event_commit
= lttng_event_commit
,
417 .event_write_from_user
= lttng_event_write_from_user
,
418 .event_memset
= lttng_event_memset
,
419 .event_write
= lttng_event_write
,
420 .event_strcpy
= lttng_event_strcpy
,
421 .packet_avail_size
= lttng_packet_avail_size
,
422 .get_writer_buf_wait_queue
= lttng_get_writer_buf_wait_queue
,
423 .get_hp_wait_queue
= lttng_get_hp_wait_queue
,
424 .is_finalized
= lttng_is_finalized
,
425 .is_disabled
= lttng_is_disabled
,
426 .timestamp_begin
= client_timestamp_begin
,
427 .timestamp_end
= client_timestamp_end
,
428 .events_discarded
= client_events_discarded
,
429 .content_size
= client_content_size
,
430 .packet_size
= client_packet_size
,
431 .stream_id
= client_stream_id
,
432 .current_timestamp
= client_current_timestamp
,
433 .sequence_number
= client_sequence_number
,
434 .instance_id
= client_instance_id
,
438 static int __init
lttng_ring_buffer_client_init(void)
441 * This vmalloc sync all also takes care of the lib ring buffer
442 * vmalloc'd module pages when it is built as a module into LTTng.
444 wrapper_vmalloc_sync_all();
445 lttng_transport_register(<tng_relay_transport
);
449 module_init(lttng_ring_buffer_client_init
);
451 static void __exit
lttng_ring_buffer_client_exit(void)
453 lttng_transport_unregister(<tng_relay_transport
);
456 module_exit(lttng_ring_buffer_client_exit
);
458 MODULE_LICENSE("GPL and additional rights");
459 MODULE_AUTHOR("Mathieu Desnoyers");
460 MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING