2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 #include <common/common.h>
24 #include <common/defaults.h>
25 #include <common/sessiond-comm/sessiond-comm.h>
28 #include "lttng-sessiond.h"
35 * Return allocated channel attributes.
37 struct lttng_channel
*channel_new_default_attr(int dom
,
38 enum lttng_buffer_type type
)
40 struct lttng_channel
*chan
;
42 chan
= zmalloc(sizeof(struct lttng_channel
));
44 PERROR("zmalloc channel init");
48 if (snprintf(chan
->name
, sizeof(chan
->name
), "%s",
49 DEFAULT_CHANNEL_NAME
) < 0) {
50 PERROR("snprintf default channel name");
54 /* Same for all domains. */
55 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
56 chan
->attr
.tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
57 chan
->attr
.tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
60 case LTTNG_DOMAIN_KERNEL
:
61 assert(type
== LTTNG_BUFFER_GLOBAL
);
62 chan
->attr
.subbuf_size
=
63 default_get_kernel_channel_subbuf_size();
64 chan
->attr
.num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
65 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
66 chan
->attr
.switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
67 chan
->attr
.read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
69 case LTTNG_DOMAIN_UST
:
71 case LTTNG_BUFFER_PER_UID
:
72 chan
->attr
.subbuf_size
= default_get_ust_uid_channel_subbuf_size();
73 chan
->attr
.num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
74 chan
->attr
.output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
75 chan
->attr
.switch_timer_interval
=
76 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
77 chan
->attr
.read_timer_interval
=
78 DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
80 case LTTNG_BUFFER_PER_PID
:
82 chan
->attr
.subbuf_size
= default_get_ust_pid_channel_subbuf_size();
83 chan
->attr
.num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
84 chan
->attr
.output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
85 chan
->attr
.switch_timer_interval
=
86 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
87 chan
->attr
.read_timer_interval
=
88 DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
93 goto error
; /* Not implemented */
105 * Disable kernel channel of the kernel session.
107 int channel_kernel_disable(struct ltt_kernel_session
*ksession
,
111 struct ltt_kernel_channel
*kchan
;
114 assert(channel_name
);
116 kchan
= trace_kernel_get_channel_by_name(channel_name
, ksession
);
118 ret
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
122 /* Only if channel is enabled disable it. */
123 if (kchan
->enabled
== 1) {
124 ret
= kernel_disable_channel(kchan
);
125 if (ret
< 0 && ret
!= -EEXIST
) {
126 ret
= LTTNG_ERR_KERN_CHAN_DISABLE_FAIL
;
138 * Enable kernel channel of the kernel session.
140 int channel_kernel_enable(struct ltt_kernel_session
*ksession
,
141 struct ltt_kernel_channel
*kchan
)
148 if (kchan
->enabled
== 0) {
149 ret
= kernel_enable_channel(kchan
);
151 ret
= LTTNG_ERR_KERN_CHAN_ENABLE_FAIL
;
155 ret
= LTTNG_ERR_KERN_CHAN_EXIST
;
166 * Create kernel channel of the kernel session and notify kernel thread.
168 int channel_kernel_create(struct ltt_kernel_session
*ksession
,
169 struct lttng_channel
*attr
, int kernel_pipe
)
172 struct lttng_channel
*defattr
= NULL
;
176 /* Creating channel attributes if needed */
178 defattr
= channel_new_default_attr(LTTNG_DOMAIN_KERNEL
,
179 LTTNG_BUFFER_GLOBAL
);
180 if (defattr
== NULL
) {
181 ret
= LTTNG_ERR_FATAL
;
187 /* Channel not found, creating it */
188 ret
= kernel_create_channel(ksession
, attr
);
190 ret
= LTTNG_ERR_KERN_CHAN_FAIL
;
194 /* Notify kernel thread that there is a new channel */
195 ret
= notify_thread_pipe(kernel_pipe
);
197 ret
= LTTNG_ERR_FATAL
;
208 * Enable UST channel for session and domain.
210 int channel_ust_enable(struct ltt_ust_session
*usess
,
211 struct ltt_ust_channel
*uchan
)
218 /* If already enabled, everything is OK */
219 if (uchan
->enabled
) {
220 DBG3("Channel %s already enabled. Skipping", uchan
->name
);
221 ret
= LTTNG_ERR_UST_CHAN_EXIST
;
225 DBG2("Channel %s being enabled in UST domain", uchan
->name
);
228 * Enable channel for UST global domain on all applications. Ignore return
229 * value here since whatever error we got, it means that the channel was
230 * not created on one or many registered applications and we can not report
231 * this to the user yet. However, at this stage, the channel was
232 * successfully created on the session daemon side so the enable-channel
233 * command is a success.
235 (void) ust_app_enable_channel_glb(usess
, uchan
);
238 DBG2("Channel %s enabled successfully", uchan
->name
);
245 * Create UST channel for session and domain.
247 int channel_ust_create(struct ltt_ust_session
*usess
,
248 struct lttng_channel
*attr
, enum lttng_buffer_type type
)
251 struct ltt_ust_channel
*uchan
= NULL
;
252 struct lttng_channel
*defattr
= NULL
;
256 /* Creating channel attributes if needed */
258 defattr
= channel_new_default_attr(LTTNG_DOMAIN_UST
, type
);
259 if (defattr
== NULL
) {
260 ret
= LTTNG_ERR_FATAL
;
267 * Validate UST buffer size and number of buffers: must both be power of 2
268 * and nonzero. We validate right here for UST, because applications will
269 * not report the error to the user (unlike kernel tracing).
271 if (!attr
->attr
.subbuf_size
||
272 (attr
->attr
.subbuf_size
& (attr
->attr
.subbuf_size
- 1))) {
273 ret
= LTTNG_ERR_INVALID
;
278 * Invalid subbuffer size if it's lower then the page size.
280 if (attr
->attr
.subbuf_size
< page_size
) {
281 ret
= LTTNG_ERR_INVALID
;
285 if (!attr
->attr
.num_subbuf
||
286 (attr
->attr
.num_subbuf
& (attr
->attr
.num_subbuf
- 1))) {
287 ret
= LTTNG_ERR_INVALID
;
291 if (attr
->attr
.output
!= LTTNG_EVENT_MMAP
) {
292 ret
= LTTNG_ERR_NOT_SUPPORTED
;
297 * The tracefile_size should not be < to the subbuf_size, otherwise
298 * we won't be able to write the packets on disk
300 if ((attr
->attr
.tracefile_size
> 0) &&
301 (attr
->attr
.tracefile_size
< attr
->attr
.subbuf_size
)) {
302 ret
= LTTNG_ERR_INVALID
;
306 /* Validate buffer type. */
308 case LTTNG_BUFFER_PER_PID
:
310 case LTTNG_BUFFER_PER_UID
:
313 ret
= LTTNG_ERR_BUFFER_NOT_SUPPORTED
;
317 /* Create UST channel */
318 uchan
= trace_ust_create_channel(attr
);
320 ret
= LTTNG_ERR_FATAL
;
324 if (trace_ust_is_max_id(usess
->used_channel_id
)) {
325 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
328 uchan
->id
= trace_ust_get_next_chan_id(usess
);
330 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64
,
331 uchan
->name
, type
, uchan
->id
);
333 /* Flag session buffer type. */
334 if (!usess
->buffer_type_changed
) {
335 usess
->buffer_type
= type
;
336 usess
->buffer_type_changed
= 1;
337 } else if (usess
->buffer_type
!= type
) {
338 /* Buffer type was already set. Refuse to create channel. */
339 ret
= LTTNG_ERR_BUFFER_TYPE_MISMATCH
;
340 goto error_free_chan
;
343 /* Enable channel for global domain */
344 ret
= ust_app_create_channel_glb(usess
, uchan
);
345 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
346 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
347 goto error_free_chan
;
350 /* Adding the channel to the channel hash table. */
352 lttng_ht_add_unique_str(usess
->domain_global
.channels
, &uchan
->node
);
355 DBG2("Channel %s created successfully", uchan
->name
);
362 * No need to remove the channel from the hash table because at this point
363 * it was not added hence the direct call and no call_rcu().
365 trace_ust_destroy_channel(uchan
);
372 * Disable UST channel for session and domain.
374 int channel_ust_disable(struct ltt_ust_session
*usess
,
375 struct ltt_ust_channel
*uchan
)
382 /* Already disabled */
383 if (uchan
->enabled
== 0) {
384 DBG2("Channel UST %s already disabled", uchan
->name
);
388 DBG2("Channel %s being disabled in UST global domain", uchan
->name
);
389 /* Disable channel for global domain */
390 ret
= ust_app_disable_channel_glb(usess
, uchan
);
391 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
392 ret
= LTTNG_ERR_UST_CHAN_DISABLE_FAIL
;
398 DBG2("Channel %s disabled successfully", uchan
->name
);