2 * Copyright (C) 2005,2006,2008 Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca)
4 * This contains the definitions for the Linux Trace Toolkit tracer.
6 * Dual LGPL v2.1/GPL v2 license.
12 #ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
13 /* Align data on its natural alignment */
14 #define RING_BUFFER_ALIGN
17 #include <linux/ringbuffer/config.h>
20 #include <linux/types.h>
21 #include <linux/limits.h>
22 #include <linux/list.h>
23 #include <linux/cache.h>
24 #include <linux/kernel.h>
25 #include <linux/timex.h>
26 #include <linux/wait.h>
27 #include <linux/marker.h>
28 #include <linux/trace-clock.h>
29 #include <asm/atomic.h>
30 #include <asm/local.h>
32 #include "ltt-tracer-core.h"
33 #include "ltt-channels.h"
35 /* Number of bytes to log with a read/write event */
36 #define LTT_LOG_RW_SIZE 32L
38 struct ltt_active_marker
;
40 /* Maximum number of callbacks per marker */
41 #define LTT_NR_CALLBACKS 10
43 struct ltt_serialize_closure
{
44 ltt_serialize_cb
*callbacks
;
45 long cb_args
[LTT_NR_CALLBACKS
];
49 size_t ltt_serialize_data(struct ltt_chanbuf
*buf
, size_t buf_offset
,
50 struct ltt_serialize_closure
*closure
,
51 void *serialize_private
, unsigned int stack_pos_ctx
,
52 int *largest_align
, const char *fmt
, va_list *args
);
54 struct ltt_available_probe
{
55 const char *name
; /* probe name */
57 marker_probe_func
*probe_func
;
58 ltt_serialize_cb callbacks
[LTT_NR_CALLBACKS
];
59 struct list_head node
; /* registered probes list */
65 LTT_CHANNEL_GLOBAL_STATE
,
66 LTT_CHANNEL_IRQ_STATE
,
67 LTT_CHANNEL_MODULE_STATE
,
68 LTT_CHANNEL_NETIF_STATE
,
69 LTT_CHANNEL_SOFTIRQ_STATE
,
70 LTT_CHANNEL_SWAP_STATE
,
71 LTT_CHANNEL_SYSCALL_STATE
,
72 LTT_CHANNEL_TASK_STATE
,
83 struct ltt_active_marker
{
84 struct list_head node
; /* active markers list */
88 struct ltt_available_probe
*probe
;
91 extern void ltt_vtrace(const struct marker
*mdata
, void *probe_data
,
92 void *call_data
, const char *fmt
, va_list *args
);
93 extern void ltt_trace(const struct marker
*mdata
, void *probe_data
,
94 void *call_data
, const char *fmt
, ...);
96 size_t ltt_serialize_printf(struct ltt_chanbuf
*buf
, unsigned long buf_offset
,
97 size_t *msg_size
, char *output
, size_t outlen
,
101 * Unique ID assigned to each registered probe.
104 MARKER_ID_SET_MARKER_ID
= 0, /* Static IDs available (range 0-7) */
105 MARKER_ID_SET_MARKER_FORMAT
,
106 MARKER_ID_COMPACT
, /* Compact IDs (range: 8-127) */
107 MARKER_ID_DYNAMIC
, /* Dynamic IDs (range: 128-65535) */
110 /* static ids 0-1 reserved for internal use. */
111 #define MARKER_CORE_IDS 2
112 static __inline__
enum marker_id
marker_id_type(uint16_t id
)
114 if (id
< MARKER_CORE_IDS
)
115 return (enum marker_id
)id
;
117 return MARKER_ID_DYNAMIC
;
120 struct user_dbg_data
{
121 unsigned long avail_size
;
126 struct ltt_trace_ops
{
127 int (*create_dirs
) (struct ltt_trace
*new_trace
);
128 void (*remove_dirs
) (struct ltt_trace
*new_trace
);
129 struct channel
*ltt_channel_create(const char *name
,
130 struct ltt_trace
*trace
,
132 size_t subbuf_size
, size_t num_subbuf
,
133 unsigned int switch_timer_interval
,
134 unsigned int read_timer_interval
);
135 void ltt_channel_destroy(struct channel
*chan
);
138 struct ltt_transport
{
140 struct module
*owner
;
141 struct list_head node
;
142 struct ltt_trace_ops ops
;
145 enum trace_mode
{ LTT_TRACE_NORMAL
, LTT_TRACE_FLIGHT
, LTT_TRACE_HYBRID
};
147 #define CHANNEL_FLAG_ENABLE (1U<<0)
148 #define CHANNEL_FLAG_OVERWRITE (1U<<1)
150 /* Per-trace information - each trace/flight recorder represented by one */
152 /* First 32 bytes cache-hot cacheline */
153 struct list_head list
;
154 struct ltt_chan
**channels
;
155 unsigned int nr_channels
;
157 /* Second 32 bytes cache-hot cacheline */
158 struct ltt_trace_ops
*ops
;
162 unsigned long long start_monotonic
;
163 struct timeval start_time
;
164 struct ltt_channel_setting
*settings
;
166 struct dentry
*trace_root
;
167 struct dentry
*ascii_root
;
169 struct kref kref
; /* Each channel has a kref of the trace struct */
170 struct ltt_transport
*transport
;
171 struct kref ltt_transport_kref
;
172 wait_queue_head_t kref_wq
; /* Place for ltt_trace_destroy to sleep */
173 char trace_name
[NAME_MAX
];
174 } ____cacheline_aligned
;
177 * Hardcoded event headers
179 * event header for a trace with active heartbeat : 27 bits timestamps
181 * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
182 * trace alignment value must be done.
184 * Remember that the C compiler does align each member on the boundary
185 * equivalent to their own size.
187 * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
188 * bytes aligned, so the buffer header and trace header are aligned.
190 * Event headers are aligned depending on the trace alignment option.
192 * Note using C structure bitfields for cross-endianness and portability
196 #define LTT_RESERVED_EVENTS 3
197 #define LTT_EVENT_BITS 5
198 #define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
199 #define LTT_TSC_BITS 27
200 #define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
202 struct event_header
{
203 u32 id_time
; /* 5 bits event id (MSB); 27 bits time (LSB) */
206 /* Reservation flags */
207 #define LTT_RFLAG_ID (1 << 0)
208 #define LTT_RFLAG_ID_SIZE (1 << 1)
209 #define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
211 #define LTT_MAX_SMALL_SIZE 0xFFFFU
214 * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
215 * specifically with CPU frequency scaling someday, so using an interpolation
216 * between the start and end of buffer values is not flexible enough. Using an
217 * immediate frequency value permits to calculate directly the times for parts
218 * of a buffer that would be before a frequency change.
220 * Keep the natural field alignment for _each field_ within this structure if
221 * you ever add/remove a field from this header. Packed attribute is not used
222 * because gcc generates poor code on at least powerpc and mips. Don't ever
223 * let gcc add padding between the structure elements.
225 struct subbuffer_header
{
226 uint64_t cycle_count_begin
; /* Cycle count at subbuffer start */
227 uint64_t cycle_count_end
; /* Cycle count at subbuffer end */
228 uint32_t magic_number
; /*
229 * Trace magic number.
230 * contains endianness information.
232 uint8_t major_version
;
233 uint8_t minor_version
;
234 uint8_t arch_size
; /* Architecture pointer size */
235 uint8_t alignment
; /* LTT data alignment */
236 uint64_t start_time_sec
; /* NTP-corrected start time */
237 uint64_t start_time_usec
;
238 uint64_t start_freq
; /*
239 * Frequency at trace start,
240 * used all along the trace.
242 uint32_t freq_scale
; /* Frequency scaling (divisor) */
243 uint32_t data_size
; /* Size of data in subbuffer */
244 uint32_t sb_size
; /* Subbuffer size (include padding) */
245 uint32_t events_lost
; /*
246 * Events lost in this subbuffer since
247 * the beginning of the trace.
250 uint32_t subbuf_corrupt
; /*
251 * Corrupted (lost) subbuffers since
252 * the begginig of the trace.
255 uint8_t header_end
[0]; /* End of header */
258 static inline notrace u64
lib_ring_buffer_clock_read(struct channel
*chan
)
260 return trace_clock_read64();
264 * record_header_size - Calculate the header size and padding necessary.
265 * @config: ring buffer instance configuration
267 * @offset: offset in the write buffer
268 * @data_size: size of the payload
269 * @pre_header_padding: padding to add before the header (output)
270 * @rflags: reservation flags
271 * @ctx: reservation context
273 * Returns the event header size (including padding).
276 * The event header must be 32-bits. The total offset calculated here :
278 * Alignment of header struct on 32 bits (min arch size, header size)
279 * + sizeof(header struct) (32-bits)
280 * + (opt) u16 (ext. event id)
281 * + (opt) u16 (event_size)
282 * (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
283 * + (opt) u32 (ext. event size)
284 * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
286 * The payload must itself determine its own alignment from the biggest type it
290 unsigned char record_header_size(const struct lib_ring_buffer_config
*config
,
291 struct channel
*chan
, size_t offset
,
292 size_t data_size
, size_t *pre_header_padding
,
294 struct lib_ring_buffer_ctx
*ctx
)
296 size_t orig_offset
= offset
;
299 BUILD_BUG_ON(sizeof(struct event_header
) != sizeof(u32
));
301 padding
= lib_ring_buffer_align(config
, offset
,
302 sizeof(struct event_header
));
304 offset
+= sizeof(struct event_header
);
306 if (unlikely(rflags
)) {
308 case LTT_RFLAG_ID_SIZE_TSC
:
309 offset
+= sizeof(u16
) + sizeof(u16
);
310 if (data_size
>= LTT_MAX_SMALL_SIZE
)
311 offset
+= sizeof(u32
);
312 offset
+= ltt_align(offset
, sizeof(u64
));
313 offset
+= sizeof(u64
);
315 case LTT_RFLAG_ID_SIZE
:
316 offset
+= sizeof(u16
) + sizeof(u16
);
317 if (data_size
>= LTT_MAX_SMALL_SIZE
)
318 offset
+= sizeof(u32
);
321 offset
+= sizeof(u16
);
326 *pre_header_padding
= padding
;
327 return offset
- orig_offset
;
330 #include <linux/ringbuffer/api.h>
333 size_t ltt_write_event_header_slow(struct ltt_chanbuf_alloc
*bufa
,
334 struct ltt_chan_alloc
*chana
,
335 long buf_offset
, u16 eID
, u32 event_size
,
336 u64 tsc
, unsigned int rflags
);
339 * ltt_write_event_header
341 * Writes the event header to the offset (already aligned on 32-bits).
343 * @config: ring buffer instance configuration
344 * @ctx: reservation context
346 * @event_size : size of the event, excluding the event header.
349 void ltt_write_event_header(const struct lib_ring_buffer_config
*config
,
350 struct lib_ring_buffer_ctx
*ctx
,
351 u16 eID
, u32 event_size
)
353 struct event_header header
;
355 if (unlikely(ctx
->rflags
))
358 header
.id_time
= eID
<< LTT_TSC_BITS
;
359 header
.id_time
|= (u32
)ctx
->tsc
& LTT_TSC_MASK
;
360 lib_ring_buffer_write(config
, ctx
, &header
, sizeof(header
));
363 ltt_write_event_header_slow(config
, ctx
, eID
, event_size
);
368 * ltt_read_event_header
369 * buf_offset must aligned on 32 bits
372 size_t ltt_read_event_header(struct ltt_chanbuf_alloc
*bufa
, long buf_offset
,
373 u64
*tsc
, u32
*event_size
, u16
*eID
,
374 unsigned int *rflags
)
376 struct ltt_event_header header
;
379 ltt_relay_read(bufa
, buf_offset
, &header
, sizeof(header
));
380 buf_offset
+= sizeof(header
);
382 *event_size
= INT_MAX
;
383 *eID
= header
.id_time
>> LTT_TSC_BITS
;
384 *tsc
= header
.id_time
& LTT_TSC_MASK
;
388 *rflags
= LTT_RFLAG_ID_SIZE_TSC
;
389 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
390 buf_offset
+= sizeof(u16
);
391 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
392 buf_offset
+= sizeof(u16
);
393 if (small_size
== LTT_MAX_SMALL_SIZE
) {
394 ltt_relay_read(bufa
, buf_offset
, event_size
,
396 buf_offset
+= sizeof(u32
);
398 *event_size
= small_size
;
399 buf_offset
+= ltt_align(buf_offset
, sizeof(u64
));
400 ltt_relay_read(bufa
, buf_offset
, tsc
, sizeof(u64
));
401 buf_offset
+= sizeof(u64
);
404 *rflags
= LTT_RFLAG_ID_SIZE
;
405 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
406 buf_offset
+= sizeof(u16
);
407 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
408 buf_offset
+= sizeof(u16
);
409 if (small_size
== LTT_MAX_SMALL_SIZE
) {
410 ltt_relay_read(bufa
, buf_offset
, event_size
,
412 buf_offset
+= sizeof(u32
);
414 *event_size
= small_size
;
417 *rflags
= LTT_RFLAG_ID
;
418 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
419 buf_offset
+= sizeof(u16
);
439 #define LTT_RELAY_ROOT "ltt"
441 #define LTT_METADATA_CHANNEL "metadata_state"
442 #define LTT_FD_STATE_CHANNEL "fd_state"
443 #define LTT_GLOBAL_STATE_CHANNEL "global_state"
444 #define LTT_IRQ_STATE_CHANNEL "irq_state"
445 #define LTT_MODULE_STATE_CHANNEL "module_state"
446 #define LTT_NETIF_STATE_CHANNEL "netif_state"
447 #define LTT_SOFTIRQ_STATE_CHANNEL "softirq_state"
448 #define LTT_SWAP_STATE_CHANNEL "swap_state"
449 #define LTT_SYSCALL_STATE_CHANNEL "syscall_state"
450 #define LTT_TASK_STATE_CHANNEL "task_state"
451 #define LTT_VM_STATE_CHANNEL "vm_state"
452 #define LTT_FS_CHANNEL "fs"
453 #define LTT_INPUT_CHANNEL "input"
454 #define LTT_IPC_CHANNEL "ipc"
455 #define LTT_KERNEL_CHANNEL "kernel"
456 #define LTT_MM_CHANNEL "mm"
457 #define LTT_RCU_CHANNEL "rcu"
459 #define LTT_FLIGHT_PREFIX "flight-"
461 #define LTT_ASCII "ascii"
463 /* Tracer properties */
464 #define LTT_DEFAULT_SUBBUF_SIZE_LOW 65536
465 #define LTT_DEFAULT_N_SUBBUFS_LOW 2
466 #define LTT_DEFAULT_SUBBUF_SIZE_MED 262144
467 #define LTT_DEFAULT_N_SUBBUFS_MED 2
468 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH 1048576
469 #define LTT_DEFAULT_N_SUBBUFS_HIGH 2
470 #define LTT_TRACER_MAGIC_NUMBER 0x00D6B7ED
471 #define LTT_TRACER_VERSION_MAJOR 2
472 #define LTT_TRACER_VERSION_MINOR 6
475 * ltt_write_trace_header - Write trace header
476 * @priv: Private data (struct trace)
477 * @header: Memory address where the information must be written to
480 void ltt_write_trace_header(void *priv
,
481 struct subbuffer_header
*header
)
483 struct ltt_trace
*trace
= priv
;
485 header
->magic_number
= LTT_TRACER_MAGIC_NUMBER
;
486 header
->major_version
= LTT_TRACER_VERSION_MAJOR
;
487 header
->minor_version
= LTT_TRACER_VERSION_MINOR
;
488 header
->arch_size
= sizeof(void *);
489 header
->alignment
= lib_ring_buffer_get_alignment();
490 header
->start_time_sec
= trace
->start_time
.tv_sec
;
491 header
->start_time_usec
= trace
->start_time
.tv_usec
;
492 header
->start_freq
= trace
->start_freq
;
493 header
->freq_scale
= trace
->freq_scale
;
497 * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
498 * nearly full buffer. User space won't use this last amount of space when in
499 * blocking mode. This space also includes the event header that would be
500 * written by this user space event.
502 #define LTT_RESERVE_CRITICAL 4096
504 /* Register and unregister function pointers */
506 enum ltt_module_function
{
507 LTT_FUNCTION_RUN_FILTER
,
508 LTT_FUNCTION_FILTER_CONTROL
,
509 LTT_FUNCTION_STATEDUMP
512 extern int ltt_module_register(enum ltt_module_function name
, void *function
,
513 struct module
*owner
);
514 extern void ltt_module_unregister(enum ltt_module_function name
);
516 void ltt_transport_register(struct ltt_transport
*transport
);
517 void ltt_transport_unregister(struct ltt_transport
*transport
);
519 /* Exported control function */
521 enum ltt_control_msg
{
524 LTT_CONTROL_CREATE_TRACE
,
525 LTT_CONTROL_DESTROY_TRACE
528 union ltt_control_args
{
530 enum trace_mode mode
;
531 unsigned int subbuf_size_low
;
532 unsigned int n_subbufs_low
;
533 unsigned int subbuf_size_med
;
534 unsigned int n_subbufs_med
;
535 unsigned int subbuf_size_high
;
536 unsigned int n_subbufs_high
;
540 int _ltt_trace_setup(const char *trace_name
);
541 int ltt_trace_setup(const char *trace_name
);
542 struct ltt_trace
*_ltt_trace_find_setup(const char *trace_name
);
543 int ltt_trace_set_type(const char *trace_name
, const char *trace_type
);
544 int ltt_trace_set_channel_subbufsize(const char *trace_name
,
545 const char *channel_name
,
547 int ltt_trace_set_channel_subbufcount(const char *trace_name
,
548 const char *channel_name
,
550 int ltt_trace_set_channel_switch_timer(const char *trace_name
,
551 const char *channel_name
,
552 unsigned long interval
);
553 int ltt_trace_set_channel_overwrite(const char *trace_name
,
554 const char *channel_name
,
555 unsigned int overwrite
);
556 int ltt_trace_alloc(const char *trace_name
);
557 int ltt_trace_destroy(const char *trace_name
);
558 int ltt_trace_start(const char *trace_name
);
559 int ltt_trace_stop(const char *trace_name
);
561 extern int ltt_control(enum ltt_control_msg msg
, const char *trace_name
,
562 const char *trace_type
, union ltt_control_args args
);
564 enum ltt_filter_control_msg
{
565 LTT_FILTER_DEFAULT_ACCEPT
,
566 LTT_FILTER_DEFAULT_REJECT
569 extern int ltt_filter_control(enum ltt_filter_control_msg msg
,
570 const char *trace_name
);
572 extern struct dentry
*get_filter_root(void);
574 void ltt_core_register(int (*function
)(u8
, void *));
576 void ltt_core_unregister(void);
578 void ltt_release_trace(struct kref
*kref
);
579 void ltt_release_transport(struct kref
*kref
);
581 extern int ltt_probe_register(struct ltt_available_probe
*pdata
);
582 extern int ltt_probe_unregister(struct ltt_available_probe
*pdata
);
583 extern int ltt_marker_connect(const char *channel
, const char *mname
,
585 extern int ltt_marker_disconnect(const char *channel
, const char *mname
,
587 extern void ltt_dump_marker_state(struct ltt_trace
*trace
);
589 void ltt_lock_traces(void);
590 void ltt_unlock_traces(void);
592 extern int ltt_ascii_create_dir(struct ltt_trace
*new_trace
);
593 extern void ltt_ascii_remove_dir(struct ltt_trace
*trace
);
594 extern int ltt_ascii_create(struct ltt_chan
*chan
);
595 extern void ltt_ascii_remove(struct ltt_chan
*chan
);
598 void ltt_statedump_register_kprobes_dump(void (*callback
)(void *call_data
));
600 void ltt_statedump_unregister_kprobes_dump(void (*callback
)(void *call_data
));
602 extern void ltt_dump_softirq_vec(void *call_data
);
604 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
605 extern void ltt_dump_sys_call_table(void *call_data
);
606 extern void ltt_dump_idt_table(void *call_data
);
608 static inline void ltt_dump_sys_call_table(void *call_data
)
612 static inline void ltt_dump_idt_table(void *call_data
)
617 #endif /* _LTT_TRACER_H */