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>
34 * Return allocated channel attributes.
36 struct lttng_channel
*channel_new_default_attr(int dom
,
37 enum lttng_buffer_type type
)
39 struct lttng_channel
*chan
;
41 chan
= zmalloc(sizeof(struct lttng_channel
));
43 PERROR("zmalloc channel init");
47 if (snprintf(chan
->name
, sizeof(chan
->name
), "%s",
48 DEFAULT_CHANNEL_NAME
) < 0) {
49 PERROR("snprintf default channel name");
53 /* Same for all domains. */
54 chan
->attr
.overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
55 chan
->attr
.tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
56 chan
->attr
.tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
59 case LTTNG_DOMAIN_KERNEL
:
60 assert(type
== LTTNG_BUFFER_GLOBAL
);
61 chan
->attr
.subbuf_size
=
62 default_get_kernel_channel_subbuf_size();
63 chan
->attr
.num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
64 chan
->attr
.output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
65 chan
->attr
.switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
66 chan
->attr
.read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
68 case LTTNG_DOMAIN_UST
:
70 case LTTNG_BUFFER_PER_UID
:
71 chan
->attr
.subbuf_size
= default_get_ust_uid_channel_subbuf_size();
72 chan
->attr
.num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
73 chan
->attr
.output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
74 chan
->attr
.switch_timer_interval
=
75 DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
76 chan
->attr
.read_timer_interval
=
77 DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
79 case LTTNG_BUFFER_PER_PID
:
81 chan
->attr
.subbuf_size
= default_get_ust_pid_channel_subbuf_size();
82 chan
->attr
.num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
83 chan
->attr
.output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
84 chan
->attr
.switch_timer_interval
=
85 DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
86 chan
->attr
.read_timer_interval
=
87 DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
92 goto error
; /* Not implemented */
104 * Disable kernel channel of the kernel session.
106 int channel_kernel_disable(struct ltt_kernel_session
*ksession
,
110 struct ltt_kernel_channel
*kchan
;
113 assert(channel_name
);
115 kchan
= trace_kernel_get_channel_by_name(channel_name
, ksession
);
117 ret
= LTTNG_ERR_KERN_CHAN_NOT_FOUND
;
121 /* Only if channel is enabled disable it. */
122 if (kchan
->enabled
== 1) {
123 ret
= kernel_disable_channel(kchan
);
124 if (ret
< 0 && ret
!= -EEXIST
) {
125 ret
= LTTNG_ERR_KERN_CHAN_DISABLE_FAIL
;
137 * Enable kernel channel of the kernel session.
139 int channel_kernel_enable(struct ltt_kernel_session
*ksession
,
140 struct ltt_kernel_channel
*kchan
)
147 if (kchan
->enabled
== 0) {
148 ret
= kernel_enable_channel(kchan
);
150 ret
= LTTNG_ERR_KERN_CHAN_ENABLE_FAIL
;
154 ret
= LTTNG_ERR_KERN_CHAN_EXIST
;
165 * Create kernel channel of the kernel session and notify kernel thread.
167 int channel_kernel_create(struct ltt_kernel_session
*ksession
,
168 struct lttng_channel
*attr
, int kernel_pipe
)
171 struct lttng_channel
*defattr
= NULL
;
175 /* Creating channel attributes if needed */
177 defattr
= channel_new_default_attr(LTTNG_DOMAIN_KERNEL
,
178 LTTNG_BUFFER_GLOBAL
);
179 if (defattr
== NULL
) {
180 ret
= LTTNG_ERR_FATAL
;
186 /* Channel not found, creating it */
187 ret
= kernel_create_channel(ksession
, attr
);
189 ret
= LTTNG_ERR_KERN_CHAN_FAIL
;
193 /* Notify kernel thread that there is a new channel */
194 ret
= notify_thread_pipe(kernel_pipe
);
196 ret
= LTTNG_ERR_FATAL
;
207 * Enable UST channel for session and domain.
209 int channel_ust_enable(struct ltt_ust_session
*usess
,
210 struct ltt_ust_channel
*uchan
)
217 /* If already enabled, everything is OK */
218 if (uchan
->enabled
) {
219 DBG3("Channel %s already enabled. Skipping", uchan
->name
);
220 ret
= LTTNG_ERR_UST_CHAN_EXIST
;
224 DBG2("Channel %s being enabled in UST domain", uchan
->name
);
227 * Enable channel for UST global domain on all applications. Ignore return
228 * value here since whatever error we got, it means that the channel was
229 * not created on one or many registered applications and we can not report
230 * this to the user yet. However, at this stage, the channel was
231 * successfully created on the session daemon side so the enable-channel
232 * command is a success.
234 (void) ust_app_enable_channel_glb(usess
, uchan
);
237 DBG2("Channel %s enabled successfully", uchan
->name
);
244 * Create UST channel for session and domain.
246 int channel_ust_create(struct ltt_ust_session
*usess
,
247 struct lttng_channel
*attr
, enum lttng_buffer_type type
)
250 struct ltt_ust_channel
*uchan
= NULL
;
251 struct lttng_channel
*defattr
= NULL
;
255 /* Creating channel attributes if needed */
257 defattr
= channel_new_default_attr(LTTNG_DOMAIN_UST
, type
);
258 if (defattr
== NULL
) {
259 ret
= LTTNG_ERR_FATAL
;
266 * Validate UST buffer size and number of buffers: must both be power of 2
267 * and nonzero. We validate right here for UST, because applications will
268 * not report the error to the user (unlike kernel tracing).
270 if (!attr
->attr
.subbuf_size
||
271 (attr
->attr
.subbuf_size
& (attr
->attr
.subbuf_size
- 1))) {
272 ret
= LTTNG_ERR_INVALID
;
276 if (!attr
->attr
.num_subbuf
||
277 (attr
->attr
.num_subbuf
& (attr
->attr
.num_subbuf
- 1))) {
278 ret
= LTTNG_ERR_INVALID
;
282 if (attr
->attr
.output
!= LTTNG_EVENT_MMAP
) {
283 ret
= LTTNG_ERR_NOT_SUPPORTED
;
288 * The tracefile_size should not be < to the subbuf_size, otherwise
289 * we won't be able to write the packets on disk
291 if ((attr
->attr
.tracefile_size
> 0) &&
292 (attr
->attr
.tracefile_size
< attr
->attr
.subbuf_size
)) {
293 ret
= LTTNG_ERR_INVALID
;
297 /* Validate buffer type. */
299 case LTTNG_BUFFER_PER_PID
:
300 if (attr
->attr
.subbuf_size
<
301 default_get_ust_pid_channel_subbuf_size()) {
302 ret
= LTTNG_ERR_INVALID
;
306 case LTTNG_BUFFER_PER_UID
:
307 if (attr
->attr
.subbuf_size
<
308 default_get_ust_uid_channel_subbuf_size()) {
309 ret
= LTTNG_ERR_INVALID
;
314 ret
= LTTNG_ERR_BUFFER_NOT_SUPPORTED
;
318 /* Create UST channel */
319 uchan
= trace_ust_create_channel(attr
);
321 ret
= LTTNG_ERR_FATAL
;
325 if (trace_ust_is_max_id(usess
->used_channel_id
)) {
326 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
329 uchan
->id
= trace_ust_get_next_chan_id(usess
);
331 DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64
,
332 uchan
->name
, type
, uchan
->id
);
334 /* Flag session buffer type. */
335 if (!usess
->buffer_type_changed
) {
336 usess
->buffer_type
= type
;
337 usess
->buffer_type_changed
= 1;
338 } else if (usess
->buffer_type
!= type
) {
339 /* Buffer type was already set. Refuse to create channel. */
340 ret
= LTTNG_ERR_BUFFER_TYPE_MISMATCH
;
341 goto error_free_chan
;
344 /* Enable channel for global domain */
345 ret
= ust_app_create_channel_glb(usess
, uchan
);
346 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
347 ret
= LTTNG_ERR_UST_CHAN_FAIL
;
348 goto error_free_chan
;
351 /* Adding the channel to the channel hash table. */
353 lttng_ht_add_unique_str(usess
->domain_global
.channels
, &uchan
->node
);
356 DBG2("Channel %s created successfully", uchan
->name
);
363 * No need to remove the channel from the hash table because at this point
364 * it was not added hence the direct call and no call_rcu().
366 trace_ust_destroy_channel(uchan
);
373 * Disable UST channel for session and domain.
375 int channel_ust_disable(struct ltt_ust_session
*usess
,
376 struct ltt_ust_channel
*uchan
)
383 /* Already disabled */
384 if (uchan
->enabled
== 0) {
385 DBG2("Channel UST %s already disabled", uchan
->name
);
389 DBG2("Channel %s being disabled in UST global domain", uchan
->name
);
390 /* Disable channel for global domain */
391 ret
= ust_app_disable_channel_glb(usess
, uchan
);
392 if (ret
< 0 && ret
!= -LTTNG_UST_ERR_EXIST
) {
393 ret
= LTTNG_ERR_UST_CHAN_DISABLE_FAIL
;
399 DBG2("Channel %s disabled successfully", uchan
->name
);