2 * ltt-ring-buffer-client.h
4 * Copyright (C) 2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 * LTTng lib ring buffer client template.
8 * Dual LGPL v2.1/GPL v2 license.
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include "trace-clock.h"
14 #include "ltt-events.h"
15 #include "ltt-tracer.h"
17 static const struct lib_ring_buffer_config client_config
;
19 static u64
client_ring_buffer_clock_read(struct channel
*chan
)
21 return lib_ring_buffer_clock_read(chan
);
25 size_t client_record_header_size(const struct lib_ring_buffer_config
*config
,
26 struct channel
*chan
, size_t offset
,
28 size_t *pre_header_padding
,
30 struct lib_ring_buffer_ctx
*ctx
)
32 return record_header_size(config
, chan
, offset
, data_size
,
33 pre_header_padding
, rflags
, ctx
);
37 * client_packet_header_size - called on buffer-switch to a new sub-buffer
39 * Return header size without padding after the structure. Don't use packed
40 * structure because gcc generates inefficient code on some architectures
43 static size_t client_packet_header_size(void)
45 return offsetof(struct packet_header
, header_end
);
48 static void client_buffer_begin(struct lib_ring_buffer
*buf
, u64 tsc
,
49 unsigned int subbuf_idx
)
51 struct channel
*chan
= buf
->backend
.chan
;
52 struct packet_header
*header
=
53 (struct packet_header
*)
54 lib_ring_buffer_offset_address(&buf
->backend
,
55 subbuf_idx
* chan
->backend
.subbuf_size
);
57 header
->timestamp_begin
= tsc
;
58 header
->content_size
= 0xFFFFFFFF; /* for debugging */
59 write_trace_header(&client_config
, header
);
63 * offset is assumed to never be 0 here : never deliver a completely empty
64 * subbuffer. data_size is between 1 and subbuf_size.
66 static void client_buffer_end(struct lib_ring_buffer
*buf
, u64 tsc
,
67 unsigned int subbuf_idx
, unsigned long data_size
)
69 struct channel
*chan
= buf
->backend
.chan
;
70 struct packet_header
*header
=
71 (struct packet_header
*)
72 lib_ring_buffer_offset_address(&buf
->backend
,
73 subbuf_idx
* chan
->backend
.subbuf_size
);
74 unsigned long records_lost
= 0;
76 header
->content_size
= data_size
;
77 header
->packet_size
= PAGE_ALIGN(data_size
);
78 header
->timestamp_end
= tsc
;
79 records_lost
+= lib_ring_buffer_get_records_lost_full(&client_config
, buf
);
80 records_lost
+= lib_ring_buffer_get_records_lost_wrap(&client_config
, buf
);
81 records_lost
+= lib_ring_buffer_get_records_lost_big(&client_config
, buf
);
82 header
->events_lost
= records_lost
;
85 static int client_buffer_create(struct lib_ring_buffer
*buf
, void *priv
,
86 int cpu
, const char *name
)
91 static void client_buffer_finalize(struct lib_ring_buffer
*buf
, void *priv
, int cpu
)
95 static const struct lib_ring_buffer_config client_config
= {
96 .cb
.ring_buffer_clock_read
= client_ring_buffer_clock_read
,
97 .cb
.record_header_size
= client_record_header_size
,
98 .cb
.subbuffer_header_size
= client_packet_header_size
,
99 .cb
.buffer_begin
= client_buffer_begin
,
100 .cb
.buffer_end
= client_buffer_end
,
101 .cb
.buffer_create
= client_buffer_create
,
102 .cb
.buffer_finalize
= client_buffer_finalize
,
105 .alloc
= RING_BUFFER_ALLOC_PER_CPU
,
106 .sync
= RING_BUFFER_SYNC_PER_CPU
,
107 .mode
= RING_BUFFER_MODE_TEMPLATE
,
108 .backend
= RING_BUFFER_PAGE
,
109 .output
= RING_BUFFER_SPLICE
,
110 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
111 .ipi
= RING_BUFFER_IPI_BARRIER
,
112 .wakeup
= RING_BUFFER_WAKEUP_BY_TIMER
,
116 struct channel
*_channel_create(const char *name
,
117 struct ltt_session
*session
, void *buf_addr
,
118 size_t subbuf_size
, size_t num_subbuf
,
119 unsigned int switch_timer_interval
,
120 unsigned int read_timer_interval
)
122 return channel_create(&client_config
, name
, session
, buf_addr
,
123 subbuf_size
, num_subbuf
, switch_timer_interval
,
124 read_timer_interval
);
128 void ltt_channel_destroy(struct channel
*chan
)
130 channel_destroy(chan
);
134 struct lib_ring_buffer
*ltt_buffer_read_open(struct channel
*chan
)
136 struct lib_ring_buffer
*buf
;
139 for_each_channel_cpu(cpu
, chan
) {
140 buf
= channel_get_ring_buffer(&client_config
, chan
, cpu
);
141 if (!lib_ring_buffer_open_read(buf
))
148 void ltt_buffer_read_close(struct lib_ring_buffer
*buf
)
150 lib_ring_buffer_release_read(buf
);
154 int ltt_event_reserve(struct lib_ring_buffer_ctx
*ctx
)
158 cpu
= lib_ring_buffer_get_cpu(&client_config
);
163 ret
= lib_ring_buffer_reserve(&client_config
, ctx
);
169 lib_ring_buffer_put_cpu(&client_config
);
173 void ltt_event_commit(struct lib_ring_buffer_ctx
*ctx
)
175 lib_ring_buffer_commit(&client_config
, ctx
);
176 lib_ring_buffer_put_cpu(&client_config
);
179 void ltt_event_write(struct lib_ring_buffer_ctx
*ctx
, const void *src
,
182 lib_ring_buffer_write(&client_config
, ctx
, src
, len
);
185 static struct ltt_transport ltt_relay_transport
= {
186 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
,
187 .owner
= THIS_MODULE
,
189 .channel_create
= _channel_create
,
190 .channel_destroy
= ltt_channel_destroy
,
191 .buffer_read_open
= ltt_buffer_read_open
,
192 .buffer_read_close
= ltt_buffer_read_close
,
193 .event_reserve
= ltt_event_reserve
,
194 .event_commit
= ltt_event_commit
,
195 .event_write
= ltt_event_write
,
199 static int __init
ltt_ring_buffer_client_init(void)
201 printk(KERN_INFO
"LTT : ltt ring buffer client init\n");
202 ltt_transport_register(<t_relay_transport
);
206 module_init(ltt_ring_buffer_client_init
);
208 static void __exit
ltt_ring_buffer_client_exit(void)
210 printk(KERN_INFO
"LTT : ltt ring buffer client exit\n");
211 ltt_transport_unregister(<t_relay_transport
);
214 module_exit(ltt_ring_buffer_client_exit
);
216 MODULE_LICENSE("GPL and additional rights");
217 MODULE_AUTHOR("Mathieu Desnoyers");
218 MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING