2 * ring buffer based function tracer
4 * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
5 * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
7 * Originally taken from the RT patch by:
8 * Arnaldo Carvalho de Melo <acme@redhat.com>
10 * Based on code from the latency_tracer, that is:
11 * Copyright (C) 2004-2006 Ingo Molnar
12 * Copyright (C) 2004 William Lee Irwin III
14 #include <linux/utsrelease.h>
15 #include <linux/kallsyms.h>
16 #include <linux/seq_file.h>
17 #include <linux/notifier.h>
18 #include <linux/debugfs.h>
19 #include <linux/pagemap.h>
20 #include <linux/hardirq.h>
21 #include <linux/linkage.h>
22 #include <linux/uaccess.h>
23 #include <linux/ftrace.h>
24 #include <linux/module.h>
25 #include <linux/percpu.h>
26 #include <linux/kdebug.h>
27 #include <linux/ctype.h>
28 #include <linux/init.h>
29 #include <linux/poll.h>
30 #include <linux/gfp.h>
32 #include <linux/kprobes.h>
33 #include <linux/writeback.h>
35 #include <linux/stacktrace.h>
39 unsigned long __read_mostly tracing_max_latency
= (cycle_t
)ULONG_MAX
;
40 unsigned long __read_mostly tracing_thresh
;
42 static unsigned long __read_mostly tracing_nr_buffers
;
43 static cpumask_t __read_mostly tracing_buffer_mask
;
45 #define for_each_tracing_cpu(cpu) \
46 for_each_cpu_mask(cpu, tracing_buffer_mask)
48 static int trace_alloc_page(void);
49 static int trace_free_page(void);
51 static int tracing_disabled
= 1;
53 static unsigned long tracing_pages_allocated
;
56 ns2usecs(cycle_t nsec
)
63 cycle_t
ftrace_now(int cpu
)
65 return cpu_clock(cpu
);
69 * The global_trace is the descriptor that holds the tracing
70 * buffers for the live tracing. For each CPU, it contains
71 * a link list of pages that will store trace entries. The
72 * page descriptor of the pages in the memory is used to hold
73 * the link list by linking the lru item in the page descriptor
74 * to each of the pages in the buffer per CPU.
76 * For each active CPU there is a data field that holds the
77 * pages for the buffer for that CPU. Each CPU has the same number
78 * of pages allocated for its buffer.
80 static struct trace_array global_trace
;
82 static DEFINE_PER_CPU(struct trace_array_cpu
, global_trace_cpu
);
85 * The max_tr is used to snapshot the global_trace when a maximum
86 * latency is reached. Some tracers will use this to store a maximum
87 * trace while it continues examining live traces.
89 * The buffers for the max_tr are set up the same as the global_trace.
90 * When a snapshot is taken, the link list of the max_tr is swapped
91 * with the link list of the global_trace and the buffers are reset for
92 * the global_trace so the tracing can continue.
94 static struct trace_array max_tr
;
96 static DEFINE_PER_CPU(struct trace_array_cpu
, max_data
);
98 /* tracer_enabled is used to toggle activation of a tracer */
99 static int tracer_enabled
= 1;
101 /* function tracing enabled */
102 int ftrace_function_enabled
;
105 * trace_nr_entries is the number of entries that is allocated
106 * for a buffer. Note, the number of entries is always rounded
107 * to ENTRIES_PER_PAGE.
109 * This number is purposely set to a low number of 16384.
110 * If the dump on oops happens, it will be much appreciated
111 * to not have to wait for all that output. Anyway this can be
112 * boot time and run time configurable.
114 #define TRACE_ENTRIES_DEFAULT 16384UL
116 static unsigned long trace_nr_entries
= TRACE_ENTRIES_DEFAULT
;
118 /* trace_types holds a link list of available tracers. */
119 static struct tracer
*trace_types __read_mostly
;
121 /* current_trace points to the tracer that is currently active */
122 static struct tracer
*current_trace __read_mostly
;
125 * max_tracer_type_len is used to simplify the allocating of
126 * buffers to read userspace tracer names. We keep track of
127 * the longest tracer name registered.
129 static int max_tracer_type_len
;
132 * trace_types_lock is used to protect the trace_types list.
133 * This lock is also used to keep user access serialized.
134 * Accesses from userspace will grab this lock while userspace
135 * activities happen inside the kernel.
137 static DEFINE_MUTEX(trace_types_lock
);
139 /* trace_wait is a waitqueue for tasks blocked on trace_poll */
140 static DECLARE_WAIT_QUEUE_HEAD(trace_wait
);
142 /* trace_flags holds iter_ctrl options */
143 unsigned long trace_flags
= TRACE_ITER_PRINT_PARENT
;
145 static notrace
void no_trace_init(struct trace_array
*tr
)
149 ftrace_function_enabled
= 0;
151 for_each_online_cpu(cpu
)
152 tracing_reset(tr
->data
[cpu
]);
156 /* dummy trace to disable tracing */
157 static struct tracer no_tracer __read_mostly
= {
159 .init
= no_trace_init
164 * trace_wake_up - wake up tasks waiting for trace input
166 * Simply wakes up any task that is blocked on the trace_wait
167 * queue. These is used with trace_poll for tasks polling the trace.
169 void trace_wake_up(void)
172 * The runqueue_is_locked() can fail, but this is the best we
175 if (!(trace_flags
& TRACE_ITER_BLOCK
) && !runqueue_is_locked())
176 wake_up(&trace_wait
);
179 #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
181 static int __init
set_nr_entries(char *str
)
183 unsigned long nr_entries
;
188 ret
= strict_strtoul(str
, 0, &nr_entries
);
189 /* nr_entries can not be zero */
190 if (ret
< 0 || nr_entries
== 0)
192 trace_nr_entries
= nr_entries
;
195 __setup("trace_entries=", set_nr_entries
);
197 unsigned long nsecs_to_usecs(unsigned long nsecs
)
203 * trace_flag_type is an enumeration that holds different
204 * states when a trace occurs. These are:
205 * IRQS_OFF - interrupts were disabled
206 * NEED_RESCED - reschedule is requested
207 * HARDIRQ - inside an interrupt handler
208 * SOFTIRQ - inside a softirq handler
209 * CONT - multiple entries hold the trace item
211 enum trace_flag_type
{
212 TRACE_FLAG_IRQS_OFF
= 0x01,
213 TRACE_FLAG_NEED_RESCHED
= 0x02,
214 TRACE_FLAG_HARDIRQ
= 0x04,
215 TRACE_FLAG_SOFTIRQ
= 0x08,
216 TRACE_FLAG_CONT
= 0x10,
220 * TRACE_ITER_SYM_MASK masks the options in trace_flags that
221 * control the output of kernel symbols.
223 #define TRACE_ITER_SYM_MASK \
224 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
226 /* These must match the bit postions in trace_iterator_flags */
227 static const char *trace_options
[] = {
243 * ftrace_max_lock is used to protect the swapping of buffers
244 * when taking a max snapshot. The buffers themselves are
245 * protected by per_cpu spinlocks. But the action of the swap
246 * needs its own lock.
248 * This is defined as a raw_spinlock_t in order to help
249 * with performance when lockdep debugging is enabled.
251 static raw_spinlock_t ftrace_max_lock
=
252 (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
255 * Copy the new maximum trace into the separate maximum-trace
256 * structure. (this way the maximum trace is permanently saved,
257 * for later retrieval via /debugfs/tracing/latency_trace)
260 __update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
262 struct trace_array_cpu
*data
= tr
->data
[cpu
];
265 max_tr
.time_start
= data
->preempt_timestamp
;
267 data
= max_tr
.data
[cpu
];
268 data
->saved_latency
= tracing_max_latency
;
270 memcpy(data
->comm
, tsk
->comm
, TASK_COMM_LEN
);
271 data
->pid
= tsk
->pid
;
272 data
->uid
= tsk
->uid
;
273 data
->nice
= tsk
->static_prio
- 20 - MAX_RT_PRIO
;
274 data
->policy
= tsk
->policy
;
275 data
->rt_priority
= tsk
->rt_priority
;
277 /* record this tasks comm */
278 tracing_record_cmdline(current
);
281 #define CHECK_COND(cond) \
282 if (unlikely(cond)) { \
283 tracing_disabled = 1; \
289 * check_pages - integrity check of trace buffers
291 * As a safty measure we check to make sure the data pages have not
294 int check_pages(struct trace_array_cpu
*data
)
296 struct page
*page
, *tmp
;
298 CHECK_COND(data
->trace_pages
.next
->prev
!= &data
->trace_pages
);
299 CHECK_COND(data
->trace_pages
.prev
->next
!= &data
->trace_pages
);
301 list_for_each_entry_safe(page
, tmp
, &data
->trace_pages
, lru
) {
302 CHECK_COND(page
->lru
.next
->prev
!= &page
->lru
);
303 CHECK_COND(page
->lru
.prev
->next
!= &page
->lru
);
310 * head_page - page address of the first page in per_cpu buffer.
312 * head_page returns the page address of the first page in
313 * a per_cpu buffer. This also preforms various consistency
314 * checks to make sure the buffer has not been corrupted.
316 void *head_page(struct trace_array_cpu
*data
)
320 if (list_empty(&data
->trace_pages
))
323 page
= list_entry(data
->trace_pages
.next
, struct page
, lru
);
324 BUG_ON(&page
->lru
== &data
->trace_pages
);
326 return page_address(page
);
330 * trace_seq_printf - sequence printing of trace information
331 * @s: trace sequence descriptor
332 * @fmt: printf format string
334 * The tracer may use either sequence operations or its own
335 * copy to user routines. To simplify formating of a trace
336 * trace_seq_printf is used to store strings into a special
337 * buffer (@s). Then the output may be either used by
338 * the sequencer or pulled into another buffer.
341 trace_seq_printf(struct trace_seq
*s
, const char *fmt
, ...)
343 int len
= (PAGE_SIZE
- 1) - s
->len
;
351 ret
= vsnprintf(s
->buffer
+ s
->len
, len
, fmt
, ap
);
354 /* If we can't write it all, don't bother writing anything */
364 * trace_seq_puts - trace sequence printing of simple string
365 * @s: trace sequence descriptor
366 * @str: simple string to record
368 * The tracer may use either the sequence operations or its own
369 * copy to user routines. This function records a simple string
370 * into a special buffer (@s) for later retrieval by a sequencer
371 * or other mechanism.
374 trace_seq_puts(struct trace_seq
*s
, const char *str
)
376 int len
= strlen(str
);
378 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
381 memcpy(s
->buffer
+ s
->len
, str
, len
);
388 trace_seq_putc(struct trace_seq
*s
, unsigned char c
)
390 if (s
->len
>= (PAGE_SIZE
- 1))
393 s
->buffer
[s
->len
++] = c
;
399 trace_seq_putmem(struct trace_seq
*s
, void *mem
, size_t len
)
401 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
404 memcpy(s
->buffer
+ s
->len
, mem
, len
);
411 static const char hex2asc
[] = "0123456789abcdef";
414 trace_seq_putmem_hex(struct trace_seq
*s
, void *mem
, size_t len
)
416 unsigned char hex
[HEX_CHARS
];
417 unsigned char *data
= mem
;
421 BUG_ON(len
>= HEX_CHARS
);
424 for (i
= 0, j
= 0; i
< len
; i
++) {
426 for (i
= len
-1, j
= 0; i
>= 0; i
--) {
430 hex
[j
++] = hex2asc
[byte
& 0x0f];
431 hex
[j
++] = hex2asc
[byte
>> 4];
435 return trace_seq_putmem(s
, hex
, j
);
439 trace_seq_reset(struct trace_seq
*s
)
445 ssize_t
trace_seq_to_user(struct trace_seq
*s
, char __user
*ubuf
, size_t cnt
)
450 if (s
->len
<= s
->readpos
)
453 len
= s
->len
- s
->readpos
;
456 ret
= copy_to_user(ubuf
, s
->buffer
+ s
->readpos
, cnt
);
465 trace_print_seq(struct seq_file
*m
, struct trace_seq
*s
)
467 int len
= s
->len
>= PAGE_SIZE
? PAGE_SIZE
- 1 : s
->len
;
470 seq_puts(m
, s
->buffer
);
476 * flip the trace buffers between two trace descriptors.
477 * This usually is the buffers between the global_trace and
478 * the max_tr to record a snapshot of a current trace.
480 * The ftrace_max_lock must be held.
483 flip_trace(struct trace_array_cpu
*tr1
, struct trace_array_cpu
*tr2
)
485 struct list_head flip_pages
;
487 INIT_LIST_HEAD(&flip_pages
);
489 memcpy(&tr1
->trace_head_idx
, &tr2
->trace_head_idx
,
490 sizeof(struct trace_array_cpu
) -
491 offsetof(struct trace_array_cpu
, trace_head_idx
));
495 list_splice_init(&tr1
->trace_pages
, &flip_pages
);
496 list_splice_init(&tr2
->trace_pages
, &tr1
->trace_pages
);
497 list_splice_init(&flip_pages
, &tr2
->trace_pages
);
498 BUG_ON(!list_empty(&flip_pages
));
504 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
506 * @tsk: the task with the latency
507 * @cpu: The cpu that initiated the trace.
509 * Flip the buffers between the @tr and the max_tr and record information
510 * about which task was the cause of this latency.
513 update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
515 struct trace_array_cpu
*data
;
518 WARN_ON_ONCE(!irqs_disabled());
519 __raw_spin_lock(&ftrace_max_lock
);
520 /* clear out all the previous traces */
521 for_each_tracing_cpu(i
) {
523 flip_trace(max_tr
.data
[i
], data
);
527 __update_max_tr(tr
, tsk
, cpu
);
528 __raw_spin_unlock(&ftrace_max_lock
);
532 * update_max_tr_single - only copy one trace over, and reset the rest
534 * @tsk - task with the latency
535 * @cpu - the cpu of the buffer to copy.
537 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
540 update_max_tr_single(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
542 struct trace_array_cpu
*data
= tr
->data
[cpu
];
545 WARN_ON_ONCE(!irqs_disabled());
546 __raw_spin_lock(&ftrace_max_lock
);
547 for_each_tracing_cpu(i
)
548 tracing_reset(max_tr
.data
[i
]);
550 flip_trace(max_tr
.data
[cpu
], data
);
553 __update_max_tr(tr
, tsk
, cpu
);
554 __raw_spin_unlock(&ftrace_max_lock
);
558 * register_tracer - register a tracer with the ftrace system.
559 * @type - the plugin for the tracer
561 * Register a new plugin tracer.
563 int register_tracer(struct tracer
*type
)
570 pr_info("Tracer must have a name\n");
574 mutex_lock(&trace_types_lock
);
575 for (t
= trace_types
; t
; t
= t
->next
) {
576 if (strcmp(type
->name
, t
->name
) == 0) {
578 pr_info("Trace %s already registered\n",
585 #ifdef CONFIG_FTRACE_STARTUP_TEST
586 if (type
->selftest
) {
587 struct tracer
*saved_tracer
= current_trace
;
588 struct trace_array_cpu
*data
;
589 struct trace_array
*tr
= &global_trace
;
590 int saved_ctrl
= tr
->ctrl
;
593 * Run a selftest on this tracer.
594 * Here we reset the trace buffer, and set the current
595 * tracer to be this tracer. The tracer can then run some
596 * internal tracing to verify that everything is in order.
597 * If we fail, we do not register this tracer.
599 for_each_tracing_cpu(i
) {
601 if (!head_page(data
))
605 current_trace
= type
;
607 /* the test is responsible for initializing and enabling */
608 pr_info("Testing tracer %s: ", type
->name
);
609 ret
= type
->selftest(type
, tr
);
610 /* the test is responsible for resetting too */
611 current_trace
= saved_tracer
;
612 tr
->ctrl
= saved_ctrl
;
614 printk(KERN_CONT
"FAILED!\n");
617 /* Only reset on passing, to avoid touching corrupted buffers */
618 for_each_tracing_cpu(i
) {
620 if (!head_page(data
))
624 printk(KERN_CONT
"PASSED\n");
628 type
->next
= trace_types
;
630 len
= strlen(type
->name
);
631 if (len
> max_tracer_type_len
)
632 max_tracer_type_len
= len
;
635 mutex_unlock(&trace_types_lock
);
640 void unregister_tracer(struct tracer
*type
)
645 mutex_lock(&trace_types_lock
);
646 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
650 pr_info("Trace %s not registered\n", type
->name
);
655 if (strlen(type
->name
) != max_tracer_type_len
)
658 max_tracer_type_len
= 0;
659 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
660 len
= strlen((*t
)->name
);
661 if (len
> max_tracer_type_len
)
662 max_tracer_type_len
= len
;
665 mutex_unlock(&trace_types_lock
);
668 void tracing_reset(struct trace_array_cpu
*data
)
672 data
->trace_head
= data
->trace_tail
= head_page(data
);
673 data
->trace_head_idx
= 0;
674 data
->trace_tail_idx
= 0;
677 #define SAVED_CMDLINES 128
678 static unsigned map_pid_to_cmdline
[PID_MAX_DEFAULT
+1];
679 static unsigned map_cmdline_to_pid
[SAVED_CMDLINES
];
680 static char saved_cmdlines
[SAVED_CMDLINES
][TASK_COMM_LEN
];
681 static int cmdline_idx
;
682 static DEFINE_SPINLOCK(trace_cmdline_lock
);
684 /* temporary disable recording */
685 atomic_t trace_record_cmdline_disabled __read_mostly
;
687 static void trace_init_cmdlines(void)
689 memset(&map_pid_to_cmdline
, -1, sizeof(map_pid_to_cmdline
));
690 memset(&map_cmdline_to_pid
, -1, sizeof(map_cmdline_to_pid
));
694 void trace_stop_cmdline_recording(void);
696 static void trace_save_cmdline(struct task_struct
*tsk
)
701 if (!tsk
->pid
|| unlikely(tsk
->pid
> PID_MAX_DEFAULT
))
705 * It's not the end of the world if we don't get
706 * the lock, but we also don't want to spin
707 * nor do we want to disable interrupts,
708 * so if we miss here, then better luck next time.
710 if (!spin_trylock(&trace_cmdline_lock
))
713 idx
= map_pid_to_cmdline
[tsk
->pid
];
714 if (idx
>= SAVED_CMDLINES
) {
715 idx
= (cmdline_idx
+ 1) % SAVED_CMDLINES
;
717 map
= map_cmdline_to_pid
[idx
];
718 if (map
<= PID_MAX_DEFAULT
)
719 map_pid_to_cmdline
[map
] = (unsigned)-1;
721 map_pid_to_cmdline
[tsk
->pid
] = idx
;
726 memcpy(&saved_cmdlines
[idx
], tsk
->comm
, TASK_COMM_LEN
);
728 spin_unlock(&trace_cmdline_lock
);
731 static char *trace_find_cmdline(int pid
)
733 char *cmdline
= "<...>";
739 if (pid
> PID_MAX_DEFAULT
)
742 map
= map_pid_to_cmdline
[pid
];
743 if (map
>= SAVED_CMDLINES
)
746 cmdline
= saved_cmdlines
[map
];
752 void tracing_record_cmdline(struct task_struct
*tsk
)
754 if (atomic_read(&trace_record_cmdline_disabled
))
757 trace_save_cmdline(tsk
);
760 static inline struct list_head
*
761 trace_next_list(struct trace_array_cpu
*data
, struct list_head
*next
)
764 * Roundrobin - but skip the head (which is not a real page):
767 if (unlikely(next
== &data
->trace_pages
))
769 BUG_ON(next
== &data
->trace_pages
);
775 trace_next_page(struct trace_array_cpu
*data
, void *addr
)
777 struct list_head
*next
;
780 page
= virt_to_page(addr
);
782 next
= trace_next_list(data
, &page
->lru
);
783 page
= list_entry(next
, struct page
, lru
);
785 return page_address(page
);
788 static inline struct trace_entry
*
789 tracing_get_trace_entry(struct trace_array
*tr
, struct trace_array_cpu
*data
)
791 unsigned long idx
, idx_next
;
792 struct trace_entry
*entry
;
795 idx
= data
->trace_head_idx
;
798 BUG_ON(idx
* TRACE_ENTRY_SIZE
>= PAGE_SIZE
);
800 entry
= data
->trace_head
+ idx
* TRACE_ENTRY_SIZE
;
802 if (unlikely(idx_next
>= ENTRIES_PER_PAGE
)) {
803 data
->trace_head
= trace_next_page(data
, data
->trace_head
);
807 if (data
->trace_head
== data
->trace_tail
&&
808 idx_next
== data
->trace_tail_idx
) {
811 data
->trace_tail_idx
++;
812 if (data
->trace_tail_idx
>= ENTRIES_PER_PAGE
) {
814 trace_next_page(data
, data
->trace_tail
);
815 data
->trace_tail_idx
= 0;
819 data
->trace_head_idx
= idx_next
;
825 tracing_generic_entry_update(struct trace_entry
*entry
, unsigned long flags
)
827 struct task_struct
*tsk
= current
;
830 pc
= preempt_count();
832 entry
->field
.preempt_count
= pc
& 0xff;
833 entry
->field
.pid
= (tsk
) ? tsk
->pid
: 0;
834 entry
->field
.t
= ftrace_now(raw_smp_processor_id());
836 (irqs_disabled_flags(flags
) ? TRACE_FLAG_IRQS_OFF
: 0) |
837 ((pc
& HARDIRQ_MASK
) ? TRACE_FLAG_HARDIRQ
: 0) |
838 ((pc
& SOFTIRQ_MASK
) ? TRACE_FLAG_SOFTIRQ
: 0) |
839 (need_resched() ? TRACE_FLAG_NEED_RESCHED
: 0);
843 trace_function(struct trace_array
*tr
, struct trace_array_cpu
*data
,
844 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
)
846 struct trace_entry
*entry
;
847 unsigned long irq_flags
;
849 raw_local_irq_save(irq_flags
);
850 __raw_spin_lock(&data
->lock
);
851 entry
= tracing_get_trace_entry(tr
, data
);
852 tracing_generic_entry_update(entry
, flags
);
853 entry
->type
= TRACE_FN
;
854 entry
->field
.fn
.ip
= ip
;
855 entry
->field
.fn
.parent_ip
= parent_ip
;
856 __raw_spin_unlock(&data
->lock
);
857 raw_local_irq_restore(irq_flags
);
861 ftrace(struct trace_array
*tr
, struct trace_array_cpu
*data
,
862 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
)
864 if (likely(!atomic_read(&data
->disabled
)))
865 trace_function(tr
, data
, ip
, parent_ip
, flags
);
868 #ifdef CONFIG_MMIOTRACE
869 void __trace_mmiotrace_rw(struct trace_array
*tr
, struct trace_array_cpu
*data
,
870 struct mmiotrace_rw
*rw
)
872 struct trace_entry
*entry
;
873 unsigned long irq_flags
;
875 raw_local_irq_save(irq_flags
);
876 __raw_spin_lock(&data
->lock
);
878 entry
= tracing_get_trace_entry(tr
, data
);
879 tracing_generic_entry_update(entry
, 0);
880 entry
->type
= TRACE_MMIO_RW
;
881 entry
->field
.mmiorw
= *rw
;
883 __raw_spin_unlock(&data
->lock
);
884 raw_local_irq_restore(irq_flags
);
889 void __trace_mmiotrace_map(struct trace_array
*tr
, struct trace_array_cpu
*data
,
890 struct mmiotrace_map
*map
)
892 struct trace_entry
*entry
;
893 unsigned long irq_flags
;
895 raw_local_irq_save(irq_flags
);
896 __raw_spin_lock(&data
->lock
);
898 entry
= tracing_get_trace_entry(tr
, data
);
899 tracing_generic_entry_update(entry
, 0);
900 entry
->type
= TRACE_MMIO_MAP
;
901 entry
->field
.mmiomap
= *map
;
903 __raw_spin_unlock(&data
->lock
);
904 raw_local_irq_restore(irq_flags
);
910 void __trace_stack(struct trace_array
*tr
,
911 struct trace_array_cpu
*data
,
915 struct trace_entry
*entry
;
916 struct stack_trace trace
;
918 if (!(trace_flags
& TRACE_ITER_STACKTRACE
))
921 entry
= tracing_get_trace_entry(tr
, data
);
922 tracing_generic_entry_update(entry
, flags
);
923 entry
->type
= TRACE_STACK
;
925 memset(&entry
->field
.stack
, 0, sizeof(entry
->field
.stack
));
927 trace
.nr_entries
= 0;
928 trace
.max_entries
= FTRACE_STACK_ENTRIES
;
930 trace
.entries
= entry
->field
.stack
.caller
;
932 save_stack_trace(&trace
);
936 __trace_special(void *__tr
, void *__data
,
937 unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
939 struct trace_array_cpu
*data
= __data
;
940 struct trace_array
*tr
= __tr
;
941 struct trace_entry
*entry
;
942 unsigned long irq_flags
;
944 raw_local_irq_save(irq_flags
);
945 __raw_spin_lock(&data
->lock
);
946 entry
= tracing_get_trace_entry(tr
, data
);
947 tracing_generic_entry_update(entry
, 0);
948 entry
->type
= TRACE_SPECIAL
;
949 entry
->field
.special
.arg1
= arg1
;
950 entry
->field
.special
.arg2
= arg2
;
951 entry
->field
.special
.arg3
= arg3
;
952 __trace_stack(tr
, data
, irq_flags
, 4);
953 __raw_spin_unlock(&data
->lock
);
954 raw_local_irq_restore(irq_flags
);
960 tracing_sched_switch_trace(struct trace_array
*tr
,
961 struct trace_array_cpu
*data
,
962 struct task_struct
*prev
,
963 struct task_struct
*next
,
966 struct trace_entry
*entry
;
967 unsigned long irq_flags
;
969 raw_local_irq_save(irq_flags
);
970 __raw_spin_lock(&data
->lock
);
971 entry
= tracing_get_trace_entry(tr
, data
);
972 tracing_generic_entry_update(entry
, flags
);
973 entry
->type
= TRACE_CTX
;
974 entry
->field
.ctx
.prev_pid
= prev
->pid
;
975 entry
->field
.ctx
.prev_prio
= prev
->prio
;
976 entry
->field
.ctx
.prev_state
= prev
->state
;
977 entry
->field
.ctx
.next_pid
= next
->pid
;
978 entry
->field
.ctx
.next_prio
= next
->prio
;
979 entry
->field
.ctx
.next_state
= next
->state
;
980 entry
->field
.ctx
.next_cpu
= task_cpu(next
);
981 __trace_stack(tr
, data
, flags
, 5);
982 __raw_spin_unlock(&data
->lock
);
983 raw_local_irq_restore(irq_flags
);
987 tracing_sched_wakeup_trace(struct trace_array
*tr
,
988 struct trace_array_cpu
*data
,
989 struct task_struct
*wakee
,
990 struct task_struct
*curr
,
993 struct trace_entry
*entry
;
994 unsigned long irq_flags
;
996 raw_local_irq_save(irq_flags
);
997 __raw_spin_lock(&data
->lock
);
998 entry
= tracing_get_trace_entry(tr
, data
);
999 tracing_generic_entry_update(entry
, flags
);
1000 entry
->type
= TRACE_WAKE
;
1001 entry
->field
.ctx
.prev_pid
= curr
->pid
;
1002 entry
->field
.ctx
.prev_prio
= curr
->prio
;
1003 entry
->field
.ctx
.prev_state
= curr
->state
;
1004 entry
->field
.ctx
.next_pid
= wakee
->pid
;
1005 entry
->field
.ctx
.next_prio
= wakee
->prio
;
1006 entry
->field
.ctx
.next_state
= wakee
->state
;
1007 entry
->field
.ctx
.next_cpu
= task_cpu(wakee
);
1008 __trace_stack(tr
, data
, flags
, 6);
1009 __raw_spin_unlock(&data
->lock
);
1010 raw_local_irq_restore(irq_flags
);
1016 ftrace_special(unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
1018 struct trace_array
*tr
= &global_trace
;
1019 struct trace_array_cpu
*data
;
1020 unsigned long flags
;
1024 if (tracing_disabled
|| current_trace
== &no_tracer
|| !tr
->ctrl
)
1027 local_irq_save(flags
);
1028 cpu
= raw_smp_processor_id();
1029 data
= tr
->data
[cpu
];
1030 disabled
= atomic_inc_return(&data
->disabled
);
1032 if (likely(disabled
== 1))
1033 __trace_special(tr
, data
, arg1
, arg2
, arg3
);
1035 atomic_dec(&data
->disabled
);
1036 local_irq_restore(flags
);
1039 #ifdef CONFIG_FTRACE
1041 function_trace_call(unsigned long ip
, unsigned long parent_ip
)
1043 struct trace_array
*tr
= &global_trace
;
1044 struct trace_array_cpu
*data
;
1045 unsigned long flags
;
1049 if (unlikely(!ftrace_function_enabled
))
1055 local_irq_save(flags
);
1056 cpu
= raw_smp_processor_id();
1057 data
= tr
->data
[cpu
];
1058 disabled
= atomic_inc_return(&data
->disabled
);
1060 if (likely(disabled
== 1))
1061 trace_function(tr
, data
, ip
, parent_ip
, flags
);
1063 atomic_dec(&data
->disabled
);
1064 local_irq_restore(flags
);
1067 static struct ftrace_ops trace_ops __read_mostly
=
1069 .func
= function_trace_call
,
1072 void tracing_start_function_trace(void)
1074 ftrace_function_enabled
= 0;
1075 register_ftrace_function(&trace_ops
);
1077 ftrace_function_enabled
= 1;
1080 void tracing_stop_function_trace(void)
1082 ftrace_function_enabled
= 0;
1083 unregister_ftrace_function(&trace_ops
);
1087 enum trace_file_type
{
1088 TRACE_FILE_LAT_FMT
= 1,
1091 /* Return the current entry. */
1092 static struct trace_entry
*
1093 trace_entry_idx(struct trace_array
*tr
, struct trace_array_cpu
*data
,
1094 struct trace_iterator
*iter
, int cpu
)
1097 struct trace_entry
*array
;
1099 if (iter
->next_idx
[cpu
] >= tr
->entries
||
1100 iter
->next_idx
[cpu
] >= data
->trace_idx
||
1101 (data
->trace_head
== data
->trace_tail
&&
1102 data
->trace_head_idx
== data
->trace_tail_idx
))
1105 if (!iter
->next_page
[cpu
]) {
1106 /* Initialize the iterator for this cpu trace buffer */
1107 WARN_ON(!data
->trace_tail
);
1108 page
= virt_to_page(data
->trace_tail
);
1109 iter
->next_page
[cpu
] = &page
->lru
;
1110 iter
->next_page_idx
[cpu
] = data
->trace_tail_idx
;
1113 page
= list_entry(iter
->next_page
[cpu
], struct page
, lru
);
1114 BUG_ON(&data
->trace_pages
== &page
->lru
);
1116 array
= page_address(page
);
1118 WARN_ON(iter
->next_page_idx
[cpu
] >= ENTRIES_PER_PAGE
);
1119 return &array
[iter
->next_page_idx
[cpu
]];
1122 /* Increment the index counter of an iterator by one */
1123 static void __trace_iterator_increment(struct trace_iterator
*iter
, int cpu
)
1125 iter
->next_idx
[cpu
]++;
1126 iter
->next_page_idx
[cpu
]++;
1128 if (iter
->next_page_idx
[cpu
] >= ENTRIES_PER_PAGE
) {
1129 struct trace_array_cpu
*data
= iter
->tr
->data
[cpu
];
1131 iter
->next_page_idx
[cpu
] = 0;
1132 iter
->next_page
[cpu
] =
1133 trace_next_list(data
, iter
->next_page
[cpu
]);
1137 static void trace_iterator_increment(struct trace_iterator
*iter
, int cpu
)
1140 __trace_iterator_increment(iter
, cpu
);
1143 static struct trace_entry
*
1144 trace_entry_next(struct trace_array
*tr
, struct trace_array_cpu
*data
,
1145 struct trace_iterator
*iter
, int cpu
)
1147 struct list_head
*next_page
;
1148 struct trace_entry
*ent
;
1149 int idx
, next_idx
, next_page_idx
;
1151 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1153 if (likely(!ent
|| ent
->type
!= TRACE_CONT
))
1156 /* save the iterator details */
1158 next_idx
= iter
->next_idx
[cpu
];
1159 next_page_idx
= iter
->next_page_idx
[cpu
];
1160 next_page
= iter
->next_page
[cpu
];
1162 /* find a real entry */
1164 __trace_iterator_increment(iter
, cpu
);
1165 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1166 } while (ent
&& ent
->type
!= TRACE_CONT
);
1168 /* reset the iterator */
1170 iter
->next_idx
[cpu
] = next_idx
;
1171 iter
->next_page_idx
[cpu
] = next_page_idx
;
1172 iter
->next_page
[cpu
] = next_page
;
1177 static struct trace_entry
*
1178 __find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
, int inc
)
1180 struct trace_array
*tr
= iter
->tr
;
1181 struct trace_entry
*ent
, *next
= NULL
;
1185 for_each_tracing_cpu(cpu
) {
1186 if (!head_page(tr
->data
[cpu
]))
1189 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1191 if (ent
&& ent
->type
== TRACE_CONT
) {
1192 struct trace_array_cpu
*data
= tr
->data
[cpu
];
1195 ent
= trace_entry_next(tr
, data
, iter
, cpu
);
1197 while (ent
&& ent
->type
== TRACE_CONT
) {
1198 __trace_iterator_increment(iter
, cpu
);
1199 ent
= trace_entry_idx(tr
, tr
->data
[cpu
],
1206 * Pick the entry with the smallest timestamp:
1208 if (ent
&& (!next
|| ent
->field
.t
< next
->field
.t
)) {
1215 *ent_cpu
= next_cpu
;
1220 /* Find the next real entry, without updating the iterator itself */
1221 static struct trace_entry
*
1222 find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
)
1224 return __find_next_entry(iter
, ent_cpu
, 0);
1227 /* Find the next real entry, and increment the iterator to the next entry */
1228 static void *find_next_entry_inc(struct trace_iterator
*iter
)
1230 struct trace_entry
*next
;
1233 next
= __find_next_entry(iter
, &next_cpu
, 1);
1235 iter
->prev_ent
= iter
->ent
;
1236 iter
->prev_cpu
= iter
->cpu
;
1239 iter
->cpu
= next_cpu
;
1242 trace_iterator_increment(iter
, iter
->cpu
);
1244 return next
? iter
: NULL
;
1247 static void trace_consume(struct trace_iterator
*iter
)
1249 struct trace_array_cpu
*data
= iter
->tr
->data
[iter
->cpu
];
1250 struct trace_entry
*ent
;
1253 data
->trace_tail_idx
++;
1254 if (data
->trace_tail_idx
>= ENTRIES_PER_PAGE
) {
1255 data
->trace_tail
= trace_next_page(data
, data
->trace_tail
);
1256 data
->trace_tail_idx
= 0;
1259 /* Check if we empty it, then reset the index */
1260 if (data
->trace_head
== data
->trace_tail
&&
1261 data
->trace_head_idx
== data
->trace_tail_idx
)
1262 data
->trace_idx
= 0;
1264 ent
= trace_entry_idx(iter
->tr
, iter
->tr
->data
[iter
->cpu
],
1266 if (ent
&& ent
->type
== TRACE_CONT
)
1270 static void *s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1272 struct trace_iterator
*iter
= m
->private;
1278 /* can't go backwards */
1283 ent
= find_next_entry_inc(iter
);
1287 while (ent
&& iter
->idx
< i
)
1288 ent
= find_next_entry_inc(iter
);
1295 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
1297 struct trace_iterator
*iter
= m
->private;
1302 mutex_lock(&trace_types_lock
);
1304 if (!current_trace
|| current_trace
!= iter
->trace
) {
1305 mutex_unlock(&trace_types_lock
);
1309 atomic_inc(&trace_record_cmdline_disabled
);
1311 /* let the tracer grab locks here if needed */
1312 if (current_trace
->start
)
1313 current_trace
->start(iter
);
1315 if (*pos
!= iter
->pos
) {
1319 iter
->prev_ent
= NULL
;
1320 iter
->prev_cpu
= -1;
1322 for_each_tracing_cpu(i
) {
1323 iter
->next_idx
[i
] = 0;
1324 iter
->next_page
[i
] = NULL
;
1327 for (p
= iter
; p
&& l
< *pos
; p
= s_next(m
, p
, &l
))
1332 p
= s_next(m
, p
, &l
);
1338 static void s_stop(struct seq_file
*m
, void *p
)
1340 struct trace_iterator
*iter
= m
->private;
1342 atomic_dec(&trace_record_cmdline_disabled
);
1344 /* let the tracer release locks here if needed */
1345 if (current_trace
&& current_trace
== iter
->trace
&& iter
->trace
->stop
)
1346 iter
->trace
->stop(iter
);
1348 mutex_unlock(&trace_types_lock
);
1351 #define KRETPROBE_MSG "[unknown/kretprobe'd]"
1353 #ifdef CONFIG_KRETPROBES
1354 static inline int kretprobed(unsigned long addr
)
1356 return addr
== (unsigned long)kretprobe_trampoline
;
1359 static inline int kretprobed(unsigned long addr
)
1363 #endif /* CONFIG_KRETPROBES */
1366 seq_print_sym_short(struct trace_seq
*s
, const char *fmt
, unsigned long address
)
1368 #ifdef CONFIG_KALLSYMS
1369 char str
[KSYM_SYMBOL_LEN
];
1371 kallsyms_lookup(address
, NULL
, NULL
, NULL
, str
);
1373 return trace_seq_printf(s
, fmt
, str
);
1379 seq_print_sym_offset(struct trace_seq
*s
, const char *fmt
,
1380 unsigned long address
)
1382 #ifdef CONFIG_KALLSYMS
1383 char str
[KSYM_SYMBOL_LEN
];
1385 sprint_symbol(str
, address
);
1386 return trace_seq_printf(s
, fmt
, str
);
1391 #ifndef CONFIG_64BIT
1392 # define IP_FMT "%08lx"
1394 # define IP_FMT "%016lx"
1398 seq_print_ip_sym(struct trace_seq
*s
, unsigned long ip
, unsigned long sym_flags
)
1403 return trace_seq_printf(s
, "0");
1405 if (sym_flags
& TRACE_ITER_SYM_OFFSET
)
1406 ret
= seq_print_sym_offset(s
, "%s", ip
);
1408 ret
= seq_print_sym_short(s
, "%s", ip
);
1413 if (sym_flags
& TRACE_ITER_SYM_ADDR
)
1414 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
1418 static void print_lat_help_header(struct seq_file
*m
)
1420 seq_puts(m
, "# _------=> CPU# \n");
1421 seq_puts(m
, "# / _-----=> irqs-off \n");
1422 seq_puts(m
, "# | / _----=> need-resched \n");
1423 seq_puts(m
, "# || / _---=> hardirq/softirq \n");
1424 seq_puts(m
, "# ||| / _--=> preempt-depth \n");
1425 seq_puts(m
, "# |||| / \n");
1426 seq_puts(m
, "# ||||| delay \n");
1427 seq_puts(m
, "# cmd pid ||||| time | caller \n");
1428 seq_puts(m
, "# \\ / ||||| \\ | / \n");
1431 static void print_func_help_header(struct seq_file
*m
)
1433 seq_puts(m
, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
1434 seq_puts(m
, "# | | | | |\n");
1439 print_trace_header(struct seq_file
*m
, struct trace_iterator
*iter
)
1441 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1442 struct trace_array
*tr
= iter
->tr
;
1443 struct trace_array_cpu
*data
= tr
->data
[tr
->cpu
];
1444 struct tracer
*type
= current_trace
;
1445 unsigned long total
= 0;
1446 unsigned long entries
= 0;
1448 const char *name
= "preemption";
1453 for_each_tracing_cpu(cpu
) {
1454 if (head_page(tr
->data
[cpu
])) {
1455 total
+= tr
->data
[cpu
]->trace_idx
;
1456 if (tr
->data
[cpu
]->trace_idx
> tr
->entries
)
1457 entries
+= tr
->entries
;
1459 entries
+= tr
->data
[cpu
]->trace_idx
;
1463 seq_printf(m
, "%s latency trace v1.1.5 on %s\n",
1465 seq_puts(m
, "-----------------------------------"
1466 "---------------------------------\n");
1467 seq_printf(m
, " latency: %lu us, #%lu/%lu, CPU#%d |"
1468 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
1469 nsecs_to_usecs(data
->saved_latency
),
1473 #if defined(CONFIG_PREEMPT_NONE)
1475 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
1477 #elif defined(CONFIG_PREEMPT)
1482 /* These are reserved for later use */
1485 seq_printf(m
, " #P:%d)\n", num_online_cpus());
1489 seq_puts(m
, " -----------------\n");
1490 seq_printf(m
, " | task: %.16s-%d "
1491 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
1492 data
->comm
, data
->pid
, data
->uid
, data
->nice
,
1493 data
->policy
, data
->rt_priority
);
1494 seq_puts(m
, " -----------------\n");
1496 if (data
->critical_start
) {
1497 seq_puts(m
, " => started at: ");
1498 seq_print_ip_sym(&iter
->seq
, data
->critical_start
, sym_flags
);
1499 trace_print_seq(m
, &iter
->seq
);
1500 seq_puts(m
, "\n => ended at: ");
1501 seq_print_ip_sym(&iter
->seq
, data
->critical_end
, sym_flags
);
1502 trace_print_seq(m
, &iter
->seq
);
1510 lat_print_generic(struct trace_seq
*s
, struct trace_entry
*entry
, int cpu
)
1512 struct trace_field
*field
= &entry
->field
;
1513 int hardirq
, softirq
;
1516 comm
= trace_find_cmdline(field
->pid
);
1518 trace_seq_printf(s
, "%8.8s-%-5d ", comm
, field
->pid
);
1519 trace_seq_printf(s
, "%3d", cpu
);
1520 trace_seq_printf(s
, "%c%c",
1521 (field
->flags
& TRACE_FLAG_IRQS_OFF
) ? 'd' : '.',
1522 ((field
->flags
& TRACE_FLAG_NEED_RESCHED
) ? 'N' : '.'));
1524 hardirq
= field
->flags
& TRACE_FLAG_HARDIRQ
;
1525 softirq
= field
->flags
& TRACE_FLAG_SOFTIRQ
;
1526 if (hardirq
&& softirq
) {
1527 trace_seq_putc(s
, 'H');
1530 trace_seq_putc(s
, 'h');
1533 trace_seq_putc(s
, 's');
1535 trace_seq_putc(s
, '.');
1539 if (field
->preempt_count
)
1540 trace_seq_printf(s
, "%x", field
->preempt_count
);
1542 trace_seq_puts(s
, ".");
1545 unsigned long preempt_mark_thresh
= 100;
1548 lat_print_timestamp(struct trace_seq
*s
, unsigned long long abs_usecs
,
1549 unsigned long rel_usecs
)
1551 trace_seq_printf(s
, " %4lldus", abs_usecs
);
1552 if (rel_usecs
> preempt_mark_thresh
)
1553 trace_seq_puts(s
, "!: ");
1554 else if (rel_usecs
> 1)
1555 trace_seq_puts(s
, "+: ");
1557 trace_seq_puts(s
, " : ");
1560 static const char state_to_char
[] = TASK_STATE_TO_CHAR_STR
;
1563 trace_seq_print_cont(struct trace_seq
*s
, struct trace_iterator
*iter
)
1565 struct trace_array
*tr
= iter
->tr
;
1566 struct trace_array_cpu
*data
= tr
->data
[iter
->cpu
];
1567 struct trace_entry
*ent
;
1569 ent
= trace_entry_idx(tr
, data
, iter
, iter
->cpu
);
1570 if (!ent
|| ent
->type
!= TRACE_CONT
) {
1571 trace_seq_putc(s
, '\n');
1576 trace_seq_printf(s
, "%s", ent
->cont
.buf
);
1577 __trace_iterator_increment(iter
, iter
->cpu
);
1578 ent
= trace_entry_idx(tr
, data
, iter
, iter
->cpu
);
1579 } while (ent
&& ent
->type
== TRACE_CONT
);
1583 print_lat_fmt(struct trace_iterator
*iter
, unsigned int trace_idx
, int cpu
)
1585 struct trace_seq
*s
= &iter
->seq
;
1586 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1587 struct trace_entry
*next_entry
= find_next_entry(iter
, NULL
);
1588 unsigned long verbose
= (trace_flags
& TRACE_ITER_VERBOSE
);
1589 struct trace_entry
*entry
= iter
->ent
;
1590 struct trace_field
*field
= &entry
->field
;
1591 unsigned long abs_usecs
;
1592 unsigned long rel_usecs
;
1601 if (entry
->type
== TRACE_CONT
)
1604 rel_usecs
= ns2usecs(next_entry
->field
.t
- entry
->field
.t
);
1605 abs_usecs
= ns2usecs(entry
->field
.t
- iter
->tr
->time_start
);
1608 comm
= trace_find_cmdline(field
->pid
);
1609 trace_seq_printf(s
, "%16s %5d %3d %d %08x %08x [%08lx]"
1610 " %ld.%03ldms (+%ld.%03ldms): ",
1612 field
->pid
, cpu
, field
->flags
,
1613 field
->preempt_count
, trace_idx
,
1616 abs_usecs
% 1000, rel_usecs
/1000,
1619 lat_print_generic(s
, entry
, cpu
);
1620 lat_print_timestamp(s
, abs_usecs
, rel_usecs
);
1622 switch (entry
->type
) {
1624 seq_print_ip_sym(s
, field
->fn
.ip
, sym_flags
);
1625 trace_seq_puts(s
, " (");
1626 if (kretprobed(field
->fn
.parent_ip
))
1627 trace_seq_puts(s
, KRETPROBE_MSG
);
1629 seq_print_ip_sym(s
, field
->fn
.parent_ip
, sym_flags
);
1630 trace_seq_puts(s
, ")\n");
1634 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1635 state_to_char
[field
->ctx
.next_state
] : 'X';
1637 state
= field
->ctx
.prev_state
?
1638 __ffs(field
->ctx
.prev_state
) + 1 : 0;
1639 S
= state
< sizeof(state_to_char
) - 1 ? state_to_char
[state
] : 'X';
1640 comm
= trace_find_cmdline(field
->ctx
.next_pid
);
1641 trace_seq_printf(s
, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
1642 field
->ctx
.prev_pid
,
1643 field
->ctx
.prev_prio
,
1644 S
, entry
->type
== TRACE_CTX
? "==>" : " +",
1645 field
->ctx
.next_cpu
,
1646 field
->ctx
.next_pid
,
1647 field
->ctx
.next_prio
,
1651 trace_seq_printf(s
, "# %ld %ld %ld\n",
1652 field
->special
.arg1
,
1653 field
->special
.arg2
,
1654 field
->special
.arg3
);
1657 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1659 trace_seq_puts(s
, " <= ");
1660 seq_print_ip_sym(s
, field
->stack
.caller
[i
], sym_flags
);
1662 trace_seq_puts(s
, "\n");
1665 seq_print_ip_sym(s
, field
->print
.ip
, sym_flags
);
1666 trace_seq_printf(s
, ": %s", field
->print
.buf
);
1667 if (field
->flags
& TRACE_FLAG_CONT
)
1668 trace_seq_print_cont(s
, iter
);
1671 trace_seq_printf(s
, "Unknown type %d\n", entry
->type
);
1676 static int print_trace_fmt(struct trace_iterator
*iter
)
1678 struct trace_seq
*s
= &iter
->seq
;
1679 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1680 struct trace_entry
*entry
;
1681 struct trace_field
*field
;
1682 unsigned long usec_rem
;
1683 unsigned long long t
;
1692 if (entry
->type
== TRACE_CONT
)
1695 field
= &entry
->field
;
1697 comm
= trace_find_cmdline(iter
->ent
->field
.pid
);
1699 t
= ns2usecs(field
->t
);
1700 usec_rem
= do_div(t
, 1000000ULL);
1701 secs
= (unsigned long)t
;
1703 ret
= trace_seq_printf(s
, "%16s-%-5d ", comm
, field
->pid
);
1706 ret
= trace_seq_printf(s
, "[%03d] ", iter
->cpu
);
1709 ret
= trace_seq_printf(s
, "%5lu.%06lu: ", secs
, usec_rem
);
1713 switch (entry
->type
) {
1715 ret
= seq_print_ip_sym(s
, field
->fn
.ip
, sym_flags
);
1718 if ((sym_flags
& TRACE_ITER_PRINT_PARENT
) &&
1719 field
->fn
.parent_ip
) {
1720 ret
= trace_seq_printf(s
, " <-");
1723 if (kretprobed(field
->fn
.parent_ip
))
1724 ret
= trace_seq_puts(s
, KRETPROBE_MSG
);
1726 ret
= seq_print_ip_sym(s
,
1727 field
->fn
.parent_ip
,
1732 ret
= trace_seq_printf(s
, "\n");
1738 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1739 state_to_char
[field
->ctx
.prev_state
] : 'X';
1740 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1741 state_to_char
[field
->ctx
.next_state
] : 'X';
1742 ret
= trace_seq_printf(s
, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n",
1743 field
->ctx
.prev_pid
,
1744 field
->ctx
.prev_prio
,
1746 entry
->type
== TRACE_CTX
? "==>" : " +",
1747 field
->ctx
.next_cpu
,
1748 field
->ctx
.next_pid
,
1749 field
->ctx
.next_prio
,
1755 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
1756 field
->special
.arg1
,
1757 field
->special
.arg2
,
1758 field
->special
.arg3
);
1763 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1765 ret
= trace_seq_puts(s
, " <= ");
1769 ret
= seq_print_ip_sym(s
, field
->stack
.caller
[i
],
1774 ret
= trace_seq_puts(s
, "\n");
1779 seq_print_ip_sym(s
, field
->print
.ip
, sym_flags
);
1780 trace_seq_printf(s
, ": %s", field
->print
.buf
);
1781 if (field
->flags
& TRACE_FLAG_CONT
)
1782 trace_seq_print_cont(s
, iter
);
1788 static int print_raw_fmt(struct trace_iterator
*iter
)
1790 struct trace_seq
*s
= &iter
->seq
;
1791 struct trace_entry
*entry
;
1792 struct trace_field
*field
;
1798 if (entry
->type
== TRACE_CONT
)
1801 field
= &entry
->field
;
1803 ret
= trace_seq_printf(s
, "%d %d %llu ",
1804 field
->pid
, iter
->cpu
, field
->t
);
1808 switch (entry
->type
) {
1810 ret
= trace_seq_printf(s
, "%x %x\n",
1812 field
->fn
.parent_ip
);
1818 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1819 state_to_char
[field
->ctx
.prev_state
] : 'X';
1820 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1821 state_to_char
[field
->ctx
.next_state
] : 'X';
1822 if (entry
->type
== TRACE_WAKE
)
1824 ret
= trace_seq_printf(s
, "%d %d %c %d %d %d %c\n",
1825 field
->ctx
.prev_pid
,
1826 field
->ctx
.prev_prio
,
1828 field
->ctx
.next_cpu
,
1829 field
->ctx
.next_pid
,
1830 field
->ctx
.next_prio
,
1837 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
1838 field
->special
.arg1
,
1839 field
->special
.arg2
,
1840 field
->special
.arg3
);
1845 trace_seq_printf(s
, "# %lx %s",
1846 field
->print
.ip
, field
->print
.buf
);
1847 if (field
->flags
& TRACE_FLAG_CONT
)
1848 trace_seq_print_cont(s
, iter
);
1854 #define SEQ_PUT_FIELD_RET(s, x) \
1856 if (!trace_seq_putmem(s, &(x), sizeof(x))) \
1860 #define SEQ_PUT_HEX_FIELD_RET(s, x) \
1862 if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
1866 static int print_hex_fmt(struct trace_iterator
*iter
)
1868 struct trace_seq
*s
= &iter
->seq
;
1869 unsigned char newline
= '\n';
1870 struct trace_entry
*entry
;
1871 struct trace_field
*field
;
1876 if (entry
->type
== TRACE_CONT
)
1879 field
= &entry
->field
;
1881 SEQ_PUT_HEX_FIELD_RET(s
, field
->pid
);
1882 SEQ_PUT_HEX_FIELD_RET(s
, iter
->cpu
);
1883 SEQ_PUT_HEX_FIELD_RET(s
, field
->t
);
1885 switch (entry
->type
) {
1887 SEQ_PUT_HEX_FIELD_RET(s
, field
->fn
.ip
);
1888 SEQ_PUT_HEX_FIELD_RET(s
, field
->fn
.parent_ip
);
1892 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1893 state_to_char
[field
->ctx
.prev_state
] : 'X';
1894 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1895 state_to_char
[field
->ctx
.next_state
] : 'X';
1896 if (entry
->type
== TRACE_WAKE
)
1898 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.prev_pid
);
1899 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.prev_prio
);
1900 SEQ_PUT_HEX_FIELD_RET(s
, S
);
1901 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.next_cpu
);
1902 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.next_pid
);
1903 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.next_prio
);
1904 SEQ_PUT_HEX_FIELD_RET(s
, T
);
1908 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg1
);
1909 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg2
);
1910 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg3
);
1913 SEQ_PUT_FIELD_RET(s
, newline
);
1918 static int print_bin_fmt(struct trace_iterator
*iter
)
1920 struct trace_seq
*s
= &iter
->seq
;
1921 struct trace_entry
*entry
;
1922 struct trace_field
*field
;
1926 if (entry
->type
== TRACE_CONT
)
1929 field
= &entry
->field
;
1931 SEQ_PUT_FIELD_RET(s
, field
->pid
);
1932 SEQ_PUT_FIELD_RET(s
, field
->cpu
);
1933 SEQ_PUT_FIELD_RET(s
, field
->t
);
1935 switch (entry
->type
) {
1937 SEQ_PUT_FIELD_RET(s
, field
->fn
.ip
);
1938 SEQ_PUT_FIELD_RET(s
, field
->fn
.parent_ip
);
1941 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_pid
);
1942 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_prio
);
1943 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_state
);
1944 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_pid
);
1945 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_prio
);
1946 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_state
);
1950 SEQ_PUT_FIELD_RET(s
, field
->special
.arg1
);
1951 SEQ_PUT_FIELD_RET(s
, field
->special
.arg2
);
1952 SEQ_PUT_FIELD_RET(s
, field
->special
.arg3
);
1958 static int trace_empty(struct trace_iterator
*iter
)
1960 struct trace_array_cpu
*data
;
1963 for_each_tracing_cpu(cpu
) {
1964 data
= iter
->tr
->data
[cpu
];
1966 if (head_page(data
) && data
->trace_idx
&&
1967 (data
->trace_tail
!= data
->trace_head
||
1968 data
->trace_tail_idx
!= data
->trace_head_idx
))
1974 static int print_trace_line(struct trace_iterator
*iter
)
1976 if (iter
->trace
&& iter
->trace
->print_line
)
1977 return iter
->trace
->print_line(iter
);
1979 if (trace_flags
& TRACE_ITER_BIN
)
1980 return print_bin_fmt(iter
);
1982 if (trace_flags
& TRACE_ITER_HEX
)
1983 return print_hex_fmt(iter
);
1985 if (trace_flags
& TRACE_ITER_RAW
)
1986 return print_raw_fmt(iter
);
1988 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
)
1989 return print_lat_fmt(iter
, iter
->idx
, iter
->cpu
);
1991 return print_trace_fmt(iter
);
1994 static int s_show(struct seq_file
*m
, void *v
)
1996 struct trace_iterator
*iter
= v
;
1998 if (iter
->ent
== NULL
) {
2000 seq_printf(m
, "# tracer: %s\n", iter
->trace
->name
);
2003 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
) {
2004 /* print nothing if the buffers are empty */
2005 if (trace_empty(iter
))
2007 print_trace_header(m
, iter
);
2008 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
2009 print_lat_help_header(m
);
2011 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
2012 print_func_help_header(m
);
2015 print_trace_line(iter
);
2016 trace_print_seq(m
, &iter
->seq
);
2022 static struct seq_operations tracer_seq_ops
= {
2029 static struct trace_iterator
*
2030 __tracing_open(struct inode
*inode
, struct file
*file
, int *ret
)
2032 struct trace_iterator
*iter
;
2034 if (tracing_disabled
) {
2039 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2045 mutex_lock(&trace_types_lock
);
2046 if (current_trace
&& current_trace
->print_max
)
2049 iter
->tr
= inode
->i_private
;
2050 iter
->trace
= current_trace
;
2053 /* TODO stop tracer */
2054 *ret
= seq_open(file
, &tracer_seq_ops
);
2056 struct seq_file
*m
= file
->private_data
;
2059 /* stop the trace while dumping */
2060 if (iter
->tr
->ctrl
) {
2062 ftrace_function_enabled
= 0;
2065 if (iter
->trace
&& iter
->trace
->open
)
2066 iter
->trace
->open(iter
);
2071 mutex_unlock(&trace_types_lock
);
2077 int tracing_open_generic(struct inode
*inode
, struct file
*filp
)
2079 if (tracing_disabled
)
2082 filp
->private_data
= inode
->i_private
;
2086 int tracing_release(struct inode
*inode
, struct file
*file
)
2088 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2089 struct trace_iterator
*iter
= m
->private;
2091 mutex_lock(&trace_types_lock
);
2092 if (iter
->trace
&& iter
->trace
->close
)
2093 iter
->trace
->close(iter
);
2095 /* reenable tracing if it was previously enabled */
2096 if (iter
->tr
->ctrl
) {
2099 * It is safe to enable function tracing even if it
2102 ftrace_function_enabled
= 1;
2104 mutex_unlock(&trace_types_lock
);
2106 seq_release(inode
, file
);
2111 static int tracing_open(struct inode
*inode
, struct file
*file
)
2115 __tracing_open(inode
, file
, &ret
);
2120 static int tracing_lt_open(struct inode
*inode
, struct file
*file
)
2122 struct trace_iterator
*iter
;
2125 iter
= __tracing_open(inode
, file
, &ret
);
2128 iter
->iter_flags
|= TRACE_FILE_LAT_FMT
;
2135 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2137 struct tracer
*t
= m
->private;
2149 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2151 struct tracer
*t
= m
->private;
2154 mutex_lock(&trace_types_lock
);
2155 for (; t
&& l
< *pos
; t
= t_next(m
, t
, &l
))
2161 static void t_stop(struct seq_file
*m
, void *p
)
2163 mutex_unlock(&trace_types_lock
);
2166 static int t_show(struct seq_file
*m
, void *v
)
2168 struct tracer
*t
= v
;
2173 seq_printf(m
, "%s", t
->name
);
2182 static struct seq_operations show_traces_seq_ops
= {
2189 static int show_traces_open(struct inode
*inode
, struct file
*file
)
2193 if (tracing_disabled
)
2196 ret
= seq_open(file
, &show_traces_seq_ops
);
2198 struct seq_file
*m
= file
->private_data
;
2199 m
->private = trace_types
;
2205 static struct file_operations tracing_fops
= {
2206 .open
= tracing_open
,
2208 .llseek
= seq_lseek
,
2209 .release
= tracing_release
,
2212 static struct file_operations tracing_lt_fops
= {
2213 .open
= tracing_lt_open
,
2215 .llseek
= seq_lseek
,
2216 .release
= tracing_release
,
2219 static struct file_operations show_traces_fops
= {
2220 .open
= show_traces_open
,
2222 .release
= seq_release
,
2226 * Only trace on a CPU if the bitmask is set:
2228 static cpumask_t tracing_cpumask
= CPU_MASK_ALL
;
2231 * When tracing/tracing_cpu_mask is modified then this holds
2232 * the new bitmask we are about to install:
2234 static cpumask_t tracing_cpumask_new
;
2237 * The tracer itself will not take this lock, but still we want
2238 * to provide a consistent cpumask to user-space:
2240 static DEFINE_MUTEX(tracing_cpumask_update_lock
);
2243 * Temporary storage for the character representation of the
2244 * CPU bitmask (and one more byte for the newline):
2246 static char mask_str
[NR_CPUS
+ 1];
2249 tracing_cpumask_read(struct file
*filp
, char __user
*ubuf
,
2250 size_t count
, loff_t
*ppos
)
2254 mutex_lock(&tracing_cpumask_update_lock
);
2256 len
= cpumask_scnprintf(mask_str
, count
, tracing_cpumask
);
2257 if (count
- len
< 2) {
2261 len
+= sprintf(mask_str
+ len
, "\n");
2262 count
= simple_read_from_buffer(ubuf
, count
, ppos
, mask_str
, NR_CPUS
+1);
2265 mutex_unlock(&tracing_cpumask_update_lock
);
2271 tracing_cpumask_write(struct file
*filp
, const char __user
*ubuf
,
2272 size_t count
, loff_t
*ppos
)
2276 mutex_lock(&tracing_cpumask_update_lock
);
2277 err
= cpumask_parse_user(ubuf
, count
, tracing_cpumask_new
);
2281 raw_local_irq_disable();
2282 __raw_spin_lock(&ftrace_max_lock
);
2283 for_each_tracing_cpu(cpu
) {
2285 * Increase/decrease the disabled counter if we are
2286 * about to flip a bit in the cpumask:
2288 if (cpu_isset(cpu
, tracing_cpumask
) &&
2289 !cpu_isset(cpu
, tracing_cpumask_new
)) {
2290 atomic_inc(&global_trace
.data
[cpu
]->disabled
);
2292 if (!cpu_isset(cpu
, tracing_cpumask
) &&
2293 cpu_isset(cpu
, tracing_cpumask_new
)) {
2294 atomic_dec(&global_trace
.data
[cpu
]->disabled
);
2297 __raw_spin_unlock(&ftrace_max_lock
);
2298 raw_local_irq_enable();
2300 tracing_cpumask
= tracing_cpumask_new
;
2302 mutex_unlock(&tracing_cpumask_update_lock
);
2307 mutex_unlock(&tracing_cpumask_update_lock
);
2312 static struct file_operations tracing_cpumask_fops
= {
2313 .open
= tracing_open_generic
,
2314 .read
= tracing_cpumask_read
,
2315 .write
= tracing_cpumask_write
,
2319 tracing_iter_ctrl_read(struct file
*filp
, char __user
*ubuf
,
2320 size_t cnt
, loff_t
*ppos
)
2327 /* calulate max size */
2328 for (i
= 0; trace_options
[i
]; i
++) {
2329 len
+= strlen(trace_options
[i
]);
2330 len
+= 3; /* "no" and space */
2333 /* +2 for \n and \0 */
2334 buf
= kmalloc(len
+ 2, GFP_KERNEL
);
2338 for (i
= 0; trace_options
[i
]; i
++) {
2339 if (trace_flags
& (1 << i
))
2340 r
+= sprintf(buf
+ r
, "%s ", trace_options
[i
]);
2342 r
+= sprintf(buf
+ r
, "no%s ", trace_options
[i
]);
2345 r
+= sprintf(buf
+ r
, "\n");
2346 WARN_ON(r
>= len
+ 2);
2348 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2356 tracing_iter_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
2357 size_t cnt
, loff_t
*ppos
)
2364 if (cnt
>= sizeof(buf
))
2367 if (copy_from_user(&buf
, ubuf
, cnt
))
2372 if (strncmp(buf
, "no", 2) == 0) {
2377 for (i
= 0; trace_options
[i
]; i
++) {
2378 int len
= strlen(trace_options
[i
]);
2380 if (strncmp(cmp
, trace_options
[i
], len
) == 0) {
2382 trace_flags
&= ~(1 << i
);
2384 trace_flags
|= (1 << i
);
2389 * If no option could be set, return an error:
2391 if (!trace_options
[i
])
2399 static struct file_operations tracing_iter_fops
= {
2400 .open
= tracing_open_generic
,
2401 .read
= tracing_iter_ctrl_read
,
2402 .write
= tracing_iter_ctrl_write
,
2405 static const char readme_msg
[] =
2406 "tracing mini-HOWTO:\n\n"
2408 "# mount -t debugfs nodev /debug\n\n"
2409 "# cat /debug/tracing/available_tracers\n"
2410 "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
2411 "# cat /debug/tracing/current_tracer\n"
2413 "# echo sched_switch > /debug/tracing/current_tracer\n"
2414 "# cat /debug/tracing/current_tracer\n"
2416 "# cat /debug/tracing/iter_ctrl\n"
2417 "noprint-parent nosym-offset nosym-addr noverbose\n"
2418 "# echo print-parent > /debug/tracing/iter_ctrl\n"
2419 "# echo 1 > /debug/tracing/tracing_enabled\n"
2420 "# cat /debug/tracing/trace > /tmp/trace.txt\n"
2421 "echo 0 > /debug/tracing/tracing_enabled\n"
2425 tracing_readme_read(struct file
*filp
, char __user
*ubuf
,
2426 size_t cnt
, loff_t
*ppos
)
2428 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
2429 readme_msg
, strlen(readme_msg
));
2432 static struct file_operations tracing_readme_fops
= {
2433 .open
= tracing_open_generic
,
2434 .read
= tracing_readme_read
,
2438 tracing_ctrl_read(struct file
*filp
, char __user
*ubuf
,
2439 size_t cnt
, loff_t
*ppos
)
2441 struct trace_array
*tr
= filp
->private_data
;
2445 r
= sprintf(buf
, "%ld\n", tr
->ctrl
);
2446 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2450 tracing_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
2451 size_t cnt
, loff_t
*ppos
)
2453 struct trace_array
*tr
= filp
->private_data
;
2458 if (cnt
>= sizeof(buf
))
2461 if (copy_from_user(&buf
, ubuf
, cnt
))
2466 ret
= strict_strtoul(buf
, 10, &val
);
2472 mutex_lock(&trace_types_lock
);
2473 if (tr
->ctrl
^ val
) {
2481 if (current_trace
&& current_trace
->ctrl_update
)
2482 current_trace
->ctrl_update(tr
);
2484 mutex_unlock(&trace_types_lock
);
2492 tracing_set_trace_read(struct file
*filp
, char __user
*ubuf
,
2493 size_t cnt
, loff_t
*ppos
)
2495 char buf
[max_tracer_type_len
+2];
2498 mutex_lock(&trace_types_lock
);
2500 r
= sprintf(buf
, "%s\n", current_trace
->name
);
2502 r
= sprintf(buf
, "\n");
2503 mutex_unlock(&trace_types_lock
);
2505 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2509 tracing_set_trace_write(struct file
*filp
, const char __user
*ubuf
,
2510 size_t cnt
, loff_t
*ppos
)
2512 struct trace_array
*tr
= &global_trace
;
2514 char buf
[max_tracer_type_len
+1];
2517 if (cnt
> max_tracer_type_len
)
2518 cnt
= max_tracer_type_len
;
2520 if (copy_from_user(&buf
, ubuf
, cnt
))
2525 /* strip ending whitespace. */
2526 for (i
= cnt
- 1; i
> 0 && isspace(buf
[i
]); i
--)
2529 mutex_lock(&trace_types_lock
);
2530 for (t
= trace_types
; t
; t
= t
->next
) {
2531 if (strcmp(t
->name
, buf
) == 0)
2534 if (!t
|| t
== current_trace
)
2537 if (current_trace
&& current_trace
->reset
)
2538 current_trace
->reset(tr
);
2545 mutex_unlock(&trace_types_lock
);
2553 tracing_max_lat_read(struct file
*filp
, char __user
*ubuf
,
2554 size_t cnt
, loff_t
*ppos
)
2556 unsigned long *ptr
= filp
->private_data
;
2560 r
= snprintf(buf
, sizeof(buf
), "%ld\n",
2561 *ptr
== (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr
));
2562 if (r
> sizeof(buf
))
2564 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2568 tracing_max_lat_write(struct file
*filp
, const char __user
*ubuf
,
2569 size_t cnt
, loff_t
*ppos
)
2571 long *ptr
= filp
->private_data
;
2576 if (cnt
>= sizeof(buf
))
2579 if (copy_from_user(&buf
, ubuf
, cnt
))
2584 ret
= strict_strtoul(buf
, 10, &val
);
2593 static atomic_t tracing_reader
;
2595 static int tracing_open_pipe(struct inode
*inode
, struct file
*filp
)
2597 struct trace_iterator
*iter
;
2599 if (tracing_disabled
)
2602 /* We only allow for reader of the pipe */
2603 if (atomic_inc_return(&tracing_reader
) != 1) {
2604 atomic_dec(&tracing_reader
);
2608 /* create a buffer to store the information to pass to userspace */
2609 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2613 mutex_lock(&trace_types_lock
);
2614 iter
->tr
= &global_trace
;
2615 iter
->trace
= current_trace
;
2616 filp
->private_data
= iter
;
2618 if (iter
->trace
->pipe_open
)
2619 iter
->trace
->pipe_open(iter
);
2620 mutex_unlock(&trace_types_lock
);
2625 static int tracing_release_pipe(struct inode
*inode
, struct file
*file
)
2627 struct trace_iterator
*iter
= file
->private_data
;
2630 atomic_dec(&tracing_reader
);
2636 tracing_poll_pipe(struct file
*filp
, poll_table
*poll_table
)
2638 struct trace_iterator
*iter
= filp
->private_data
;
2640 if (trace_flags
& TRACE_ITER_BLOCK
) {
2642 * Always select as readable when in blocking mode
2644 return POLLIN
| POLLRDNORM
;
2646 if (!trace_empty(iter
))
2647 return POLLIN
| POLLRDNORM
;
2648 poll_wait(filp
, &trace_wait
, poll_table
);
2649 if (!trace_empty(iter
))
2650 return POLLIN
| POLLRDNORM
;
2660 tracing_read_pipe(struct file
*filp
, char __user
*ubuf
,
2661 size_t cnt
, loff_t
*ppos
)
2663 struct trace_iterator
*iter
= filp
->private_data
;
2664 struct trace_array_cpu
*data
;
2665 static cpumask_t mask
;
2666 unsigned long flags
;
2667 #ifdef CONFIG_FTRACE
2673 /* return any leftover data */
2674 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
2679 trace_seq_reset(&iter
->seq
);
2681 mutex_lock(&trace_types_lock
);
2682 if (iter
->trace
->read
) {
2683 sret
= iter
->trace
->read(iter
, filp
, ubuf
, cnt
, ppos
);
2688 while (trace_empty(iter
)) {
2690 if ((filp
->f_flags
& O_NONBLOCK
)) {
2696 * This is a make-shift waitqueue. The reason we don't use
2697 * an actual wait queue is because:
2698 * 1) we only ever have one waiter
2699 * 2) the tracing, traces all functions, we don't want
2700 * the overhead of calling wake_up and friends
2701 * (and tracing them too)
2702 * Anyway, this is really very primitive wakeup.
2704 set_current_state(TASK_INTERRUPTIBLE
);
2705 iter
->tr
->waiter
= current
;
2707 mutex_unlock(&trace_types_lock
);
2709 /* sleep for 100 msecs, and try again. */
2710 schedule_timeout(HZ
/10);
2712 mutex_lock(&trace_types_lock
);
2714 iter
->tr
->waiter
= NULL
;
2716 if (signal_pending(current
)) {
2721 if (iter
->trace
!= current_trace
)
2725 * We block until we read something and tracing is disabled.
2726 * We still block if tracing is disabled, but we have never
2727 * read anything. This allows a user to cat this file, and
2728 * then enable tracing. But after we have read something,
2729 * we give an EOF when tracing is again disabled.
2731 * iter->pos will be 0 if we haven't read anything.
2733 if (!tracer_enabled
&& iter
->pos
)
2739 /* stop when tracing is finished */
2740 if (trace_empty(iter
))
2743 if (cnt
>= PAGE_SIZE
)
2744 cnt
= PAGE_SIZE
- 1;
2746 /* reset all but tr, trace, and overruns */
2747 memset(&iter
->seq
, 0,
2748 sizeof(struct trace_iterator
) -
2749 offsetof(struct trace_iterator
, seq
));
2753 * We need to stop all tracing on all CPUS to read the
2754 * the next buffer. This is a bit expensive, but is
2755 * not done often. We fill all what we can read,
2756 * and then release the locks again.
2760 local_irq_save(flags
);
2761 #ifdef CONFIG_FTRACE
2762 ftrace_save
= ftrace_enabled
;
2766 for_each_tracing_cpu(cpu
) {
2767 data
= iter
->tr
->data
[cpu
];
2769 if (!head_page(data
) || !data
->trace_idx
)
2772 atomic_inc(&data
->disabled
);
2776 for_each_cpu_mask(cpu
, mask
) {
2777 data
= iter
->tr
->data
[cpu
];
2778 __raw_spin_lock(&data
->lock
);
2780 if (data
->overrun
> iter
->last_overrun
[cpu
])
2781 iter
->overrun
[cpu
] +=
2782 data
->overrun
- iter
->last_overrun
[cpu
];
2783 iter
->last_overrun
[cpu
] = data
->overrun
;
2786 while (find_next_entry_inc(iter
) != NULL
) {
2788 int len
= iter
->seq
.len
;
2790 ret
= print_trace_line(iter
);
2792 /* don't print partial lines */
2793 iter
->seq
.len
= len
;
2797 trace_consume(iter
);
2799 if (iter
->seq
.len
>= cnt
)
2803 for_each_cpu_mask(cpu
, mask
) {
2804 data
= iter
->tr
->data
[cpu
];
2805 __raw_spin_unlock(&data
->lock
);
2808 for_each_cpu_mask(cpu
, mask
) {
2809 data
= iter
->tr
->data
[cpu
];
2810 atomic_dec(&data
->disabled
);
2812 #ifdef CONFIG_FTRACE
2813 ftrace_enabled
= ftrace_save
;
2815 local_irq_restore(flags
);
2817 /* Now copy what we have to the user */
2818 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
2819 if (iter
->seq
.readpos
>= iter
->seq
.len
)
2820 trace_seq_reset(&iter
->seq
);
2825 mutex_unlock(&trace_types_lock
);
2831 tracing_entries_read(struct file
*filp
, char __user
*ubuf
,
2832 size_t cnt
, loff_t
*ppos
)
2834 struct trace_array
*tr
= filp
->private_data
;
2838 r
= sprintf(buf
, "%lu\n", tr
->entries
);
2839 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2843 tracing_entries_write(struct file
*filp
, const char __user
*ubuf
,
2844 size_t cnt
, loff_t
*ppos
)
2850 if (cnt
>= sizeof(buf
))
2853 if (copy_from_user(&buf
, ubuf
, cnt
))
2858 ret
= strict_strtoul(buf
, 10, &val
);
2862 /* must have at least 1 entry */
2866 mutex_lock(&trace_types_lock
);
2868 if (current_trace
!= &no_tracer
) {
2870 pr_info("ftrace: set current_tracer to none"
2871 " before modifying buffer size\n");
2875 if (val
> global_trace
.entries
) {
2876 long pages_requested
;
2877 unsigned long freeable_pages
;
2879 /* make sure we have enough memory before mapping */
2881 (val
+ (ENTRIES_PER_PAGE
-1)) / ENTRIES_PER_PAGE
;
2883 /* account for each buffer (and max_tr) */
2884 pages_requested
*= tracing_nr_buffers
* 2;
2886 /* Check for overflow */
2887 if (pages_requested
< 0) {
2892 freeable_pages
= determine_dirtyable_memory();
2894 /* we only allow to request 1/4 of useable memory */
2895 if (pages_requested
>
2896 ((freeable_pages
+ tracing_pages_allocated
) / 4)) {
2901 while (global_trace
.entries
< val
) {
2902 if (trace_alloc_page()) {
2906 /* double check that we don't go over the known pages */
2907 if (tracing_pages_allocated
> pages_requested
)
2912 /* include the number of entries in val (inc of page entries) */
2913 while (global_trace
.entries
> val
+ (ENTRIES_PER_PAGE
- 1))
2917 /* check integrity */
2918 for_each_tracing_cpu(i
)
2919 check_pages(global_trace
.data
[i
]);
2923 /* If check pages failed, return ENOMEM */
2924 if (tracing_disabled
)
2927 max_tr
.entries
= global_trace
.entries
;
2928 mutex_unlock(&trace_types_lock
);
2933 static struct file_operations tracing_max_lat_fops
= {
2934 .open
= tracing_open_generic
,
2935 .read
= tracing_max_lat_read
,
2936 .write
= tracing_max_lat_write
,
2939 static struct file_operations tracing_ctrl_fops
= {
2940 .open
= tracing_open_generic
,
2941 .read
= tracing_ctrl_read
,
2942 .write
= tracing_ctrl_write
,
2945 static struct file_operations set_tracer_fops
= {
2946 .open
= tracing_open_generic
,
2947 .read
= tracing_set_trace_read
,
2948 .write
= tracing_set_trace_write
,
2951 static struct file_operations tracing_pipe_fops
= {
2952 .open
= tracing_open_pipe
,
2953 .poll
= tracing_poll_pipe
,
2954 .read
= tracing_read_pipe
,
2955 .release
= tracing_release_pipe
,
2958 static struct file_operations tracing_entries_fops
= {
2959 .open
= tracing_open_generic
,
2960 .read
= tracing_entries_read
,
2961 .write
= tracing_entries_write
,
2964 #ifdef CONFIG_DYNAMIC_FTRACE
2967 tracing_read_long(struct file
*filp
, char __user
*ubuf
,
2968 size_t cnt
, loff_t
*ppos
)
2970 unsigned long *p
= filp
->private_data
;
2974 r
= sprintf(buf
, "%ld\n", *p
);
2976 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2979 static struct file_operations tracing_read_long_fops
= {
2980 .open
= tracing_open_generic
,
2981 .read
= tracing_read_long
,
2985 static struct dentry
*d_tracer
;
2987 struct dentry
*tracing_init_dentry(void)
2994 d_tracer
= debugfs_create_dir("tracing", NULL
);
2996 if (!d_tracer
&& !once
) {
2998 pr_warning("Could not create debugfs directory 'tracing'\n");
3005 #ifdef CONFIG_FTRACE_SELFTEST
3006 /* Let selftest have access to static functions in this file */
3007 #include "trace_selftest.c"
3010 static __init
void tracer_init_debugfs(void)
3012 struct dentry
*d_tracer
;
3013 struct dentry
*entry
;
3015 d_tracer
= tracing_init_dentry();
3017 entry
= debugfs_create_file("tracing_enabled", 0644, d_tracer
,
3018 &global_trace
, &tracing_ctrl_fops
);
3020 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
3022 entry
= debugfs_create_file("iter_ctrl", 0644, d_tracer
,
3023 NULL
, &tracing_iter_fops
);
3025 pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
3027 entry
= debugfs_create_file("tracing_cpumask", 0644, d_tracer
,
3028 NULL
, &tracing_cpumask_fops
);
3030 pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
3032 entry
= debugfs_create_file("latency_trace", 0444, d_tracer
,
3033 &global_trace
, &tracing_lt_fops
);
3035 pr_warning("Could not create debugfs 'latency_trace' entry\n");
3037 entry
= debugfs_create_file("trace", 0444, d_tracer
,
3038 &global_trace
, &tracing_fops
);
3040 pr_warning("Could not create debugfs 'trace' entry\n");
3042 entry
= debugfs_create_file("available_tracers", 0444, d_tracer
,
3043 &global_trace
, &show_traces_fops
);
3045 pr_warning("Could not create debugfs 'available_tracers' entry\n");
3047 entry
= debugfs_create_file("current_tracer", 0444, d_tracer
,
3048 &global_trace
, &set_tracer_fops
);
3050 pr_warning("Could not create debugfs 'current_tracer' entry\n");
3052 entry
= debugfs_create_file("tracing_max_latency", 0644, d_tracer
,
3053 &tracing_max_latency
,
3054 &tracing_max_lat_fops
);
3056 pr_warning("Could not create debugfs "
3057 "'tracing_max_latency' entry\n");
3059 entry
= debugfs_create_file("tracing_thresh", 0644, d_tracer
,
3060 &tracing_thresh
, &tracing_max_lat_fops
);
3062 pr_warning("Could not create debugfs "
3063 "'tracing_thresh' entry\n");
3064 entry
= debugfs_create_file("README", 0644, d_tracer
,
3065 NULL
, &tracing_readme_fops
);
3067 pr_warning("Could not create debugfs 'README' entry\n");
3069 entry
= debugfs_create_file("trace_pipe", 0644, d_tracer
,
3070 NULL
, &tracing_pipe_fops
);
3072 pr_warning("Could not create debugfs "
3073 "'trace_pipe' entry\n");
3075 entry
= debugfs_create_file("trace_entries", 0644, d_tracer
,
3076 &global_trace
, &tracing_entries_fops
);
3078 pr_warning("Could not create debugfs "
3079 "'trace_entries' entry\n");
3081 #ifdef CONFIG_DYNAMIC_FTRACE
3082 entry
= debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer
,
3083 &ftrace_update_tot_cnt
,
3084 &tracing_read_long_fops
);
3086 pr_warning("Could not create debugfs "
3087 "'dyn_ftrace_total_info' entry\n");
3089 #ifdef CONFIG_SYSPROF_TRACER
3090 init_tracer_sysprof_debugfs(d_tracer
);
3094 #define TRACE_BUF_SIZE 1024
3095 #define TRACE_PRINT_BUF_SIZE \
3096 (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf))
3097 #define TRACE_CONT_BUF_SIZE sizeof(struct trace_field)
3099 int __ftrace_printk(unsigned long ip
, const char *fmt
, ...)
3101 static DEFINE_SPINLOCK(trace_buf_lock
);
3102 static char trace_buf
[TRACE_BUF_SIZE
];
3104 struct trace_array
*tr
= &global_trace
;
3105 struct trace_array_cpu
*data
;
3106 struct trace_entry
*entry
;
3107 unsigned long flags
;
3110 int cpu
, len
= 0, write
, written
= 0;
3112 if (!(trace_flags
& TRACE_ITER_PRINTK
) || !tr
->ctrl
|| tracing_disabled
)
3115 local_irq_save(flags
);
3116 cpu
= raw_smp_processor_id();
3117 data
= tr
->data
[cpu
];
3118 disabled
= atomic_inc_return(&data
->disabled
);
3120 if (unlikely(disabled
!= 1))
3123 spin_lock(&trace_buf_lock
);
3125 len
= vsnprintf(trace_buf
, TRACE_BUF_SIZE
, fmt
, ap
);
3128 len
= min(len
, TRACE_BUF_SIZE
-1);
3131 __raw_spin_lock(&data
->lock
);
3132 entry
= tracing_get_trace_entry(tr
, data
);
3133 tracing_generic_entry_update(entry
, flags
);
3134 entry
->type
= TRACE_PRINT
;
3135 entry
->field
.print
.ip
= ip
;
3137 write
= min(len
, (int)(TRACE_PRINT_BUF_SIZE
-1));
3139 memcpy(&entry
->field
.print
.buf
, trace_buf
, write
);
3140 entry
->field
.print
.buf
[write
] = 0;
3144 entry
->field
.flags
|= TRACE_FLAG_CONT
;
3146 while (written
!= len
) {
3147 entry
= tracing_get_trace_entry(tr
, data
);
3149 entry
->type
= TRACE_CONT
;
3150 write
= min(len
- written
, (int)(TRACE_CONT_BUF_SIZE
-1));
3151 memcpy(&entry
->cont
.buf
, trace_buf
+written
, write
);
3152 entry
->cont
.buf
[write
] = 0;
3155 __raw_spin_unlock(&data
->lock
);
3157 spin_unlock(&trace_buf_lock
);
3160 atomic_dec(&data
->disabled
);
3161 local_irq_restore(flags
);
3165 EXPORT_SYMBOL_GPL(__ftrace_printk
);
3167 static int trace_panic_handler(struct notifier_block
*this,
3168 unsigned long event
, void *unused
)
3174 static struct notifier_block trace_panic_notifier
= {
3175 .notifier_call
= trace_panic_handler
,
3177 .priority
= 150 /* priority: INT_MAX >= x >= 0 */
3180 static int trace_die_handler(struct notifier_block
*self
,
3194 static struct notifier_block trace_die_notifier
= {
3195 .notifier_call
= trace_die_handler
,
3200 * printk is set to max of 1024, we really don't need it that big.
3201 * Nothing should be printing 1000 characters anyway.
3203 #define TRACE_MAX_PRINT 1000
3206 * Define here KERN_TRACE so that we have one place to modify
3207 * it if we decide to change what log level the ftrace dump
3210 #define KERN_TRACE KERN_INFO
3213 trace_printk_seq(struct trace_seq
*s
)
3215 /* Probably should print a warning here. */
3219 /* should be zero ended, but we are paranoid. */
3220 s
->buffer
[s
->len
] = 0;
3222 printk(KERN_TRACE
"%s", s
->buffer
);
3228 void ftrace_dump(void)
3230 static DEFINE_SPINLOCK(ftrace_dump_lock
);
3231 /* use static because iter can be a bit big for the stack */
3232 static struct trace_iterator iter
;
3233 struct trace_array_cpu
*data
;
3234 static cpumask_t mask
;
3235 static int dump_ran
;
3236 unsigned long flags
;
3241 spin_lock_irqsave(&ftrace_dump_lock
, flags
);
3247 /* No turning back! */
3248 ftrace_kill_atomic();
3250 printk(KERN_TRACE
"Dumping ftrace buffer:\n");
3252 iter
.tr
= &global_trace
;
3253 iter
.trace
= current_trace
;
3256 * We need to stop all tracing on all CPUS to read the
3257 * the next buffer. This is a bit expensive, but is
3258 * not done often. We fill all what we can read,
3259 * and then release the locks again.
3264 for_each_tracing_cpu(cpu
) {
3265 data
= iter
.tr
->data
[cpu
];
3267 if (!head_page(data
) || !data
->trace_idx
)
3270 atomic_inc(&data
->disabled
);
3274 for_each_cpu_mask(cpu
, mask
) {
3275 data
= iter
.tr
->data
[cpu
];
3276 __raw_spin_lock(&data
->lock
);
3278 if (data
->overrun
> iter
.last_overrun
[cpu
])
3279 iter
.overrun
[cpu
] +=
3280 data
->overrun
- iter
.last_overrun
[cpu
];
3281 iter
.last_overrun
[cpu
] = data
->overrun
;
3284 while (!trace_empty(&iter
)) {
3287 printk(KERN_TRACE
"---------------------------------\n");
3291 /* reset all but tr, trace, and overruns */
3292 memset(&iter
.seq
, 0,
3293 sizeof(struct trace_iterator
) -
3294 offsetof(struct trace_iterator
, seq
));
3295 iter
.iter_flags
|= TRACE_FILE_LAT_FMT
;
3298 if (find_next_entry_inc(&iter
) != NULL
) {
3299 print_trace_line(&iter
);
3300 trace_consume(&iter
);
3303 trace_printk_seq(&iter
.seq
);
3307 printk(KERN_TRACE
" (ftrace buffer empty)\n");
3309 printk(KERN_TRACE
"---------------------------------\n");
3311 for_each_cpu_mask(cpu
, mask
) {
3312 data
= iter
.tr
->data
[cpu
];
3313 __raw_spin_unlock(&data
->lock
);
3316 for_each_cpu_mask(cpu
, mask
) {
3317 data
= iter
.tr
->data
[cpu
];
3318 atomic_dec(&data
->disabled
);
3323 spin_unlock_irqrestore(&ftrace_dump_lock
, flags
);
3326 static int trace_alloc_page(void)
3328 struct trace_array_cpu
*data
;
3329 struct page
*page
, *tmp
;
3332 unsigned pages_allocated
= 0;
3335 /* first allocate a page for each CPU */
3336 for_each_tracing_cpu(i
) {
3337 array
= (void *)__get_free_page(GFP_KERNEL
);
3338 if (array
== NULL
) {
3339 printk(KERN_ERR
"tracer: failed to allocate page"
3340 "for trace buffer!\n");
3345 page
= virt_to_page(array
);
3346 list_add(&page
->lru
, &pages
);
3348 /* Only allocate if we are actually using the max trace */
3349 #ifdef CONFIG_TRACER_MAX_TRACE
3350 array
= (void *)__get_free_page(GFP_KERNEL
);
3351 if (array
== NULL
) {
3352 printk(KERN_ERR
"tracer: failed to allocate page"
3353 "for trace buffer!\n");
3357 page
= virt_to_page(array
);
3358 list_add(&page
->lru
, &pages
);
3362 /* Now that we successfully allocate a page per CPU, add them */
3363 for_each_tracing_cpu(i
) {
3364 data
= global_trace
.data
[i
];
3365 page
= list_entry(pages
.next
, struct page
, lru
);
3366 list_del_init(&page
->lru
);
3367 list_add_tail(&page
->lru
, &data
->trace_pages
);
3370 #ifdef CONFIG_TRACER_MAX_TRACE
3371 data
= max_tr
.data
[i
];
3372 page
= list_entry(pages
.next
, struct page
, lru
);
3373 list_del_init(&page
->lru
);
3374 list_add_tail(&page
->lru
, &data
->trace_pages
);
3378 tracing_pages_allocated
+= pages_allocated
;
3379 global_trace
.entries
+= ENTRIES_PER_PAGE
;
3384 list_for_each_entry_safe(page
, tmp
, &pages
, lru
) {
3385 list_del_init(&page
->lru
);
3391 static int trace_free_page(void)
3393 struct trace_array_cpu
*data
;
3395 struct list_head
*p
;
3399 /* free one page from each buffer */
3400 for_each_tracing_cpu(i
) {
3401 data
= global_trace
.data
[i
];
3402 p
= data
->trace_pages
.next
;
3403 if (p
== &data
->trace_pages
) {
3404 /* should never happen */
3406 tracing_disabled
= 1;
3410 page
= list_entry(p
, struct page
, lru
);
3412 list_del(&page
->lru
);
3413 tracing_pages_allocated
--;
3414 tracing_pages_allocated
--;
3417 tracing_reset(data
);
3419 #ifdef CONFIG_TRACER_MAX_TRACE
3420 data
= max_tr
.data
[i
];
3421 p
= data
->trace_pages
.next
;
3422 if (p
== &data
->trace_pages
) {
3423 /* should never happen */
3425 tracing_disabled
= 1;
3429 page
= list_entry(p
, struct page
, lru
);
3431 list_del(&page
->lru
);
3434 tracing_reset(data
);
3437 global_trace
.entries
-= ENTRIES_PER_PAGE
;
3442 __init
static int tracer_alloc_buffers(void)
3444 struct trace_array_cpu
*data
;
3451 /* TODO: make the number of buffers hot pluggable with CPUS */
3452 tracing_nr_buffers
= num_possible_cpus();
3453 tracing_buffer_mask
= cpu_possible_map
;
3455 /* Allocate the first page for all buffers */
3456 for_each_tracing_cpu(i
) {
3457 data
= global_trace
.data
[i
] = &per_cpu(global_trace_cpu
, i
);
3458 max_tr
.data
[i
] = &per_cpu(max_data
, i
);
3460 array
= (void *)__get_free_page(GFP_KERNEL
);
3461 if (array
== NULL
) {
3462 printk(KERN_ERR
"tracer: failed to allocate page"
3463 "for trace buffer!\n");
3467 /* set the array to the list */
3468 INIT_LIST_HEAD(&data
->trace_pages
);
3469 page
= virt_to_page(array
);
3470 list_add(&page
->lru
, &data
->trace_pages
);
3471 /* use the LRU flag to differentiate the two buffers */
3474 data
->lock
= (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
3475 max_tr
.data
[i
]->lock
= (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
3477 /* Only allocate if we are actually using the max trace */
3478 #ifdef CONFIG_TRACER_MAX_TRACE
3479 array
= (void *)__get_free_page(GFP_KERNEL
);
3480 if (array
== NULL
) {
3481 printk(KERN_ERR
"tracer: failed to allocate page"
3482 "for trace buffer!\n");
3486 INIT_LIST_HEAD(&max_tr
.data
[i
]->trace_pages
);
3487 page
= virt_to_page(array
);
3488 list_add(&page
->lru
, &max_tr
.data
[i
]->trace_pages
);
3494 * Since we allocate by orders of pages, we may be able to
3497 global_trace
.entries
= ENTRIES_PER_PAGE
;
3500 while (global_trace
.entries
< trace_nr_entries
) {
3501 if (trace_alloc_page())
3505 max_tr
.entries
= global_trace
.entries
;
3507 pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
3508 pages
, trace_nr_entries
, (long)TRACE_ENTRY_SIZE
);
3509 pr_info(" actual entries %ld\n", global_trace
.entries
);
3511 tracer_init_debugfs();
3513 trace_init_cmdlines();
3515 register_tracer(&no_tracer
);
3516 current_trace
= &no_tracer
;
3518 /* All seems OK, enable tracing */
3519 global_trace
.ctrl
= tracer_enabled
;
3520 tracing_disabled
= 0;
3522 atomic_notifier_chain_register(&panic_notifier_list
,
3523 &trace_panic_notifier
);
3525 register_die_notifier(&trace_die_notifier
);
3530 for (i
-- ; i
>= 0; i
--) {
3531 struct page
*page
, *tmp
;
3532 struct trace_array_cpu
*data
= global_trace
.data
[i
];
3535 list_for_each_entry_safe(page
, tmp
,
3536 &data
->trace_pages
, lru
) {
3537 list_del_init(&page
->lru
);
3542 #ifdef CONFIG_TRACER_MAX_TRACE
3543 data
= max_tr
.data
[i
];
3545 list_for_each_entry_safe(page
, tmp
,
3546 &data
->trace_pages
, lru
) {
3547 list_del_init(&page
->lru
);
3555 fs_initcall(tracer_alloc_buffers
);