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 <linux/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_subbuffer_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_subbuffer_header_size(void)
45 return offsetof(struct subbuffer_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 subbuffer_header
*header
=
53 (struct subbuffer_header
*)
54 lib_ring_buffer_offset_address(&buf
->backend
,
55 subbuf_idx
* chan
->backend
.subbuf_size
);
57 header
->cycle_count_begin
= tsc
;
58 header
->data_size
= 0xFFFFFFFF; /* for debugging */
59 write_trace_header(chan
->backend
.priv
, 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 subbuffer_header
*header
=
71 (struct subbuffer_header
*)
72 lib_ring_buffer_offset_address(&buf
->backend
,
73 subbuf_idx
* chan
->backend
.subbuf_size
);
74 unsigned long records_lost
= 0;
76 header
->data_size
= data_size
;
77 header
->subbuf_size
= PAGE_ALIGN(data_size
);
78 header
->cycle_count_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
;
83 header
->subbuf_corrupt
= 0; /* deprecated */
86 static int client_buffer_create(struct lib_ring_buffer
*buf
, void *priv
,
87 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_subbuffer_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 #ifdef RING_BUFFER_ALIGN
109 .align
= RING_BUFFER_NATURAL
,
111 .align
= RING_BUFFER_PACKED
,
113 .backend
= RING_BUFFER_PAGE
,
114 .output
= RING_BUFFER_SPLICE
,
115 .oops
= RING_BUFFER_OOPS_CONSISTENCY
,
116 .ipi
= RING_BUFFER_IPI_BARRIER
,
117 .wakeup
= RING_BUFFER_WAKEUP_BY_TIMER
,
121 struct channel
*ltt_channel_create(struct ltt_session
*session
, void *buf_addr
,
122 size_t subbuf_size
, size_t num_subbuf
,
123 unsigned int switch_timer_interval
,
124 unsigned int read_timer_interval
)
126 return channel_create(&client_config
, "[lttng]", session
, buf_addr
,
127 subbuf_size
, num_subbuf
, switch_timer_interval
,
128 read_timer_interval
);
132 void ltt_channel_destroy(struct channel
*chan
)
134 channel_destroy(chan
);
138 struct lib_ring_buffer
*ltt_buffer_read_open(struct channel
*chan
)
140 struct lib_ring_buffer
*buf
;
143 for_each_channel_cpu(cpu
, chan
->chan
) {
144 buf
= channel_get_ring_buffer(&config_config
, chan
, cpu
);
145 if (!lib_ring_buffer_open_read(buf
))
152 struct lib_ring_buffer
*ltt_buffer_read_close(struct lib_ring_buffer
*buf
)
154 lib_ring_buffer_release_read(buf
);
157 static struct ltt_transport ltt_relay_transport
= {
158 .name
= "relay-" RING_BUFFER_MODE_TEMPLATE_STRING
,
159 .owner
= THIS_MODULE
,
161 .create_channel
= ltt_channel_create
,
162 .destroy_channel
= ltt_channel_destroy
,
163 .buffer_read_open
= ltt_buffer_read_open
,
164 .buffer_read_close
= ltt_buffer_read_close
,
168 static int __init
ltt_ring_buffer_client_init(void)
170 printk(KERN_INFO
"LTT : ltt ring buffer client init\n");
171 ltt_transport_register(<t_relay_transport
);
175 static void __exit
ltt_ring_buffer_client_exit(void)
177 printk(KERN_INFO
"LTT : ltt ring buffer client exit\n");
178 ltt_transport_unregister(<t_relay_transport
);
181 MODULE_LICENSE("GPL and additional rights");
182 MODULE_AUTHOR("Mathieu Desnoyers");
183 MODULE_DESCRIPTION("LTTng ring buffer " RING_BUFFER_MODE_TEMPLATE_STRING