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 enum trace_mode
{ LTT_TRACE_NORMAL
, LTT_TRACE_FLIGHT
, LTT_TRACE_HYBRID
};
128 #define CHANNEL_FLAG_ENABLE (1U<<0)
129 #define CHANNEL_FLAG_OVERWRITE (1U<<1)
132 /* Per-trace information - each trace/flight recorder represented by one */
134 /* First 32 bytes cache-hot cacheline */
135 struct list_head list
;
136 struct ltt_chan
**channels
;
137 unsigned int nr_channels
;
139 /* Second 32 bytes cache-hot cacheline */
140 struct ltt_trace_ops
*ops
;
144 unsigned long long start_monotonic
;
145 struct timeval start_time
;
146 struct ltt_channel_setting
*settings
;
148 struct dentry
*trace_root
;
149 struct dentry
*ascii_root
;
151 struct kref kref
; /* Each channel has a kref of the trace struct */
152 struct ltt_transport
*transport
;
153 struct kref ltt_transport_kref
;
154 wait_queue_head_t kref_wq
; /* Place for ltt_trace_destroy to sleep */
155 char trace_name
[NAME_MAX
];
156 } ____cacheline_aligned
;
160 * Hardcoded event headers
162 * event header for a trace with active heartbeat : 27 bits timestamps
164 * headers are 32-bits aligned. In order to insure such alignment, a dynamic per
165 * trace alignment value must be done.
167 * Remember that the C compiler does align each member on the boundary
168 * equivalent to their own size.
170 * As relay subbuffers are aligned on pages, we are sure that they are 4 and 8
171 * bytes aligned, so the buffer header and trace header are aligned.
173 * Event headers are aligned depending on the trace alignment option.
175 * Note using C structure bitfields for cross-endianness and portability
179 #define LTT_RESERVED_EVENTS 3
180 #define LTT_EVENT_BITS 5
181 #define LTT_FREE_EVENTS ((1 << LTT_EVENT_BITS) - LTT_RESERVED_EVENTS)
182 #define LTT_TSC_BITS 27
183 #define LTT_TSC_MASK ((1 << LTT_TSC_BITS) - 1)
185 struct event_header
{
186 u32 id_time
; /* 5 bits event id (MSB); 27 bits time (LSB) */
189 /* Reservation flags */
190 #define LTT_RFLAG_ID (1 << 0)
191 #define LTT_RFLAG_ID_SIZE (1 << 1)
192 #define LTT_RFLAG_ID_SIZE_TSC (1 << 2)
194 #define LTT_MAX_SMALL_SIZE 0xFFFFU
197 * We use asm/timex.h : cpu_khz/HZ variable in here : we might have to deal
198 * specifically with CPU frequency scaling someday, so using an interpolation
199 * between the start and end of buffer values is not flexible enough. Using an
200 * immediate frequency value permits to calculate directly the times for parts
201 * of a buffer that would be before a frequency change.
203 * Keep the natural field alignment for _each field_ within this structure if
204 * you ever add/remove a field from this header. Packed attribute is not used
205 * because gcc generates poor code on at least powerpc and mips. Don't ever
206 * let gcc add padding between the structure elements.
208 struct subbuffer_header
{
209 uint64_t cycle_count_begin
; /* Cycle count at subbuffer start */
210 uint64_t cycle_count_end
; /* Cycle count at subbuffer end */
211 uint32_t magic_number
; /*
212 * Trace magic number.
213 * contains endianness information.
215 uint8_t major_version
;
216 uint8_t minor_version
;
217 uint8_t arch_size
; /* Architecture pointer size */
218 uint8_t alignment
; /* LTT data alignment */
219 uint64_t start_time_sec
; /* NTP-corrected start time */
220 uint64_t start_time_usec
;
221 uint64_t start_freq
; /*
222 * Frequency at trace start,
223 * used all along the trace.
225 uint32_t freq_scale
; /* Frequency scaling (divisor) */
226 uint32_t data_size
; /* Size of data in subbuffer */
227 uint32_t sb_size
; /* Subbuffer size (include padding) */
228 uint32_t events_lost
; /*
229 * Events lost in this subbuffer since
230 * the beginning of the trace.
233 uint32_t subbuf_corrupt
; /*
234 * Corrupted (lost) subbuffers since
235 * the begginig of the trace.
238 uint8_t header_end
[0]; /* End of header */
241 static inline notrace u64
lib_ring_buffer_clock_read(struct channel
*chan
)
243 return trace_clock_read64();
247 * record_header_size - Calculate the header size and padding necessary.
248 * @config: ring buffer instance configuration
250 * @offset: offset in the write buffer
251 * @data_size: size of the payload
252 * @pre_header_padding: padding to add before the header (output)
253 * @rflags: reservation flags
254 * @ctx: reservation context
256 * Returns the event header size (including padding).
259 * The event header must be 32-bits. The total offset calculated here :
261 * Alignment of header struct on 32 bits (min arch size, header size)
262 * + sizeof(header struct) (32-bits)
263 * + (opt) u16 (ext. event id)
264 * + (opt) u16 (event_size)
265 * (if event_size == LTT_MAX_SMALL_SIZE, has ext. event size)
266 * + (opt) u32 (ext. event size)
267 * + (opt) u64 full TSC (aligned on min(64-bits, arch size))
269 * The payload must itself determine its own alignment from the biggest type it
273 unsigned char record_header_size(const struct lib_ring_buffer_config
*config
,
274 struct channel
*chan
, size_t offset
,
275 size_t data_size
, size_t *pre_header_padding
,
277 struct lib_ring_buffer_ctx
*ctx
)
279 size_t orig_offset
= offset
;
282 BUILD_BUG_ON(sizeof(struct event_header
) != sizeof(u32
));
284 padding
= lib_ring_buffer_align(config
, offset
,
285 sizeof(struct event_header
));
287 offset
+= sizeof(struct event_header
);
289 if (unlikely(rflags
)) {
291 case LTT_RFLAG_ID_SIZE_TSC
:
292 offset
+= sizeof(u16
) + sizeof(u16
);
293 if (data_size
>= LTT_MAX_SMALL_SIZE
)
294 offset
+= sizeof(u32
);
295 offset
+= ltt_align(offset
, sizeof(u64
));
296 offset
+= sizeof(u64
);
298 case LTT_RFLAG_ID_SIZE
:
299 offset
+= sizeof(u16
) + sizeof(u16
);
300 if (data_size
>= LTT_MAX_SMALL_SIZE
)
301 offset
+= sizeof(u32
);
304 offset
+= sizeof(u16
);
309 *pre_header_padding
= padding
;
310 return offset
- orig_offset
;
313 #include <linux/ringbuffer/api.h>
316 size_t ltt_write_event_header_slow(struct ltt_chanbuf_alloc
*bufa
,
317 struct ltt_chan_alloc
*chana
,
318 long buf_offset
, u16 eID
, u32 event_size
,
319 u64 tsc
, unsigned int rflags
);
322 * ltt_write_event_header
324 * Writes the event header to the offset (already aligned on 32-bits).
326 * @config: ring buffer instance configuration
327 * @ctx: reservation context
329 * @event_size : size of the event, excluding the event header.
332 void ltt_write_event_header(const struct lib_ring_buffer_config
*config
,
333 struct lib_ring_buffer_ctx
*ctx
,
334 u16 eID
, u32 event_size
)
336 struct event_header header
;
338 if (unlikely(ctx
->rflags
))
341 header
.id_time
= eID
<< LTT_TSC_BITS
;
342 header
.id_time
|= (u32
)ctx
->tsc
& LTT_TSC_MASK
;
343 lib_ring_buffer_write(config
, ctx
, &header
, sizeof(header
));
346 ltt_write_event_header_slow(config
, ctx
, eID
, event_size
);
351 * ltt_read_event_header
352 * buf_offset must aligned on 32 bits
355 size_t ltt_read_event_header(struct ltt_chanbuf_alloc
*bufa
, long buf_offset
,
356 u64
*tsc
, u32
*event_size
, u16
*eID
,
357 unsigned int *rflags
)
359 struct ltt_event_header header
;
362 ltt_relay_read(bufa
, buf_offset
, &header
, sizeof(header
));
363 buf_offset
+= sizeof(header
);
365 *event_size
= INT_MAX
;
366 *eID
= header
.id_time
>> LTT_TSC_BITS
;
367 *tsc
= header
.id_time
& LTT_TSC_MASK
;
371 *rflags
= LTT_RFLAG_ID_SIZE_TSC
;
372 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
373 buf_offset
+= sizeof(u16
);
374 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
375 buf_offset
+= sizeof(u16
);
376 if (small_size
== LTT_MAX_SMALL_SIZE
) {
377 ltt_relay_read(bufa
, buf_offset
, event_size
,
379 buf_offset
+= sizeof(u32
);
381 *event_size
= small_size
;
382 buf_offset
+= ltt_align(buf_offset
, sizeof(u64
));
383 ltt_relay_read(bufa
, buf_offset
, tsc
, sizeof(u64
));
384 buf_offset
+= sizeof(u64
);
387 *rflags
= LTT_RFLAG_ID_SIZE
;
388 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
389 buf_offset
+= sizeof(u16
);
390 ltt_relay_read(bufa
, buf_offset
, &small_size
, sizeof(u16
));
391 buf_offset
+= sizeof(u16
);
392 if (small_size
== LTT_MAX_SMALL_SIZE
) {
393 ltt_relay_read(bufa
, buf_offset
, event_size
,
395 buf_offset
+= sizeof(u32
);
397 *event_size
= small_size
;
400 *rflags
= LTT_RFLAG_ID
;
401 ltt_relay_read(bufa
, buf_offset
, eID
, sizeof(u16
));
402 buf_offset
+= sizeof(u16
);
422 #define LTT_RELAY_ROOT "ltt"
424 #define LTT_METADATA_CHANNEL "metadata_state"
425 #define LTT_FD_STATE_CHANNEL "fd_state"
426 #define LTT_GLOBAL_STATE_CHANNEL "global_state"
427 #define LTT_IRQ_STATE_CHANNEL "irq_state"
428 #define LTT_MODULE_STATE_CHANNEL "module_state"
429 #define LTT_NETIF_STATE_CHANNEL "netif_state"
430 #define LTT_SOFTIRQ_STATE_CHANNEL "softirq_state"
431 #define LTT_SWAP_STATE_CHANNEL "swap_state"
432 #define LTT_SYSCALL_STATE_CHANNEL "syscall_state"
433 #define LTT_TASK_STATE_CHANNEL "task_state"
434 #define LTT_VM_STATE_CHANNEL "vm_state"
435 #define LTT_FS_CHANNEL "fs"
436 #define LTT_INPUT_CHANNEL "input"
437 #define LTT_IPC_CHANNEL "ipc"
438 #define LTT_KERNEL_CHANNEL "kernel"
439 #define LTT_MM_CHANNEL "mm"
440 #define LTT_RCU_CHANNEL "rcu"
442 #define LTT_FLIGHT_PREFIX "flight-"
444 #define LTT_ASCII "ascii"
446 /* Tracer properties */
447 #define LTT_DEFAULT_SUBBUF_SIZE_LOW 65536
448 #define LTT_DEFAULT_N_SUBBUFS_LOW 2
449 #define LTT_DEFAULT_SUBBUF_SIZE_MED 262144
450 #define LTT_DEFAULT_N_SUBBUFS_MED 2
451 #define LTT_DEFAULT_SUBBUF_SIZE_HIGH 1048576
452 #define LTT_DEFAULT_N_SUBBUFS_HIGH 2
453 #define LTT_TRACER_MAGIC_NUMBER 0x00D6B7ED
454 #define LTT_TRACER_VERSION_MAJOR 2
455 #define LTT_TRACER_VERSION_MINOR 6
458 * ltt_write_trace_header - Write trace header
459 * @priv: Private data (struct trace)
460 * @header: Memory address where the information must be written to
463 void ltt_write_trace_header(void *priv
,
464 struct subbuffer_header
*header
)
466 struct ltt_trace
*trace
= priv
;
468 header
->magic_number
= LTT_TRACER_MAGIC_NUMBER
;
469 header
->major_version
= LTT_TRACER_VERSION_MAJOR
;
470 header
->minor_version
= LTT_TRACER_VERSION_MINOR
;
471 header
->arch_size
= sizeof(void *);
472 header
->alignment
= lib_ring_buffer_get_alignment();
473 header
->start_time_sec
= trace
->start_time
.tv_sec
;
474 header
->start_time_usec
= trace
->start_time
.tv_usec
;
475 header
->start_freq
= trace
->start_freq
;
476 header
->freq_scale
= trace
->freq_scale
;
480 * Size reserved for high priority events (interrupts, NMI, BH) at the end of a
481 * nearly full buffer. User space won't use this last amount of space when in
482 * blocking mode. This space also includes the event header that would be
483 * written by this user space event.
485 #define LTT_RESERVE_CRITICAL 4096
487 /* Register and unregister function pointers */
489 enum ltt_module_function
{
490 LTT_FUNCTION_RUN_FILTER
,
491 LTT_FUNCTION_FILTER_CONTROL
,
492 LTT_FUNCTION_STATEDUMP
495 extern int ltt_module_register(enum ltt_module_function name
, void *function
,
496 struct module
*owner
);
497 extern void ltt_module_unregister(enum ltt_module_function name
);
499 /* Exported control function */
501 enum ltt_control_msg
{
504 LTT_CONTROL_CREATE_TRACE
,
505 LTT_CONTROL_DESTROY_TRACE
508 union ltt_control_args
{
510 enum trace_mode mode
;
511 unsigned int subbuf_size_low
;
512 unsigned int n_subbufs_low
;
513 unsigned int subbuf_size_med
;
514 unsigned int n_subbufs_med
;
515 unsigned int subbuf_size_high
;
516 unsigned int n_subbufs_high
;
520 void ltt_core_register(int (*function
)(u8
, void *));
522 void ltt_core_unregister(void);
524 extern int ltt_probe_register(struct ltt_available_probe
*pdata
);
525 extern int ltt_probe_unregister(struct ltt_available_probe
*pdata
);
526 extern int ltt_marker_connect(const char *channel
, const char *mname
,
528 extern int ltt_marker_disconnect(const char *channel
, const char *mname
,
530 extern void ltt_dump_marker_state(struct ltt_trace
*trace
);
533 void ltt_statedump_register_kprobes_dump(void (*callback
)(void *call_data
));
535 void ltt_statedump_unregister_kprobes_dump(void (*callback
)(void *call_data
));
537 extern void ltt_dump_softirq_vec(void *call_data
);
539 #ifdef CONFIG_HAVE_LTT_DUMP_TABLES
540 extern void ltt_dump_sys_call_table(void *call_data
);
541 extern void ltt_dump_idt_table(void *call_data
);
543 static inline void ltt_dump_sys_call_table(void *call_data
)
547 static inline void ltt_dump_idt_table(void *call_data
)
552 #endif /* _LTT_TRACER_H */