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
[] = {
242 * ftrace_max_lock is used to protect the swapping of buffers
243 * when taking a max snapshot. The buffers themselves are
244 * protected by per_cpu spinlocks. But the action of the swap
245 * needs its own lock.
247 * This is defined as a raw_spinlock_t in order to help
248 * with performance when lockdep debugging is enabled.
250 static raw_spinlock_t ftrace_max_lock
=
251 (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
254 * Copy the new maximum trace into the separate maximum-trace
255 * structure. (this way the maximum trace is permanently saved,
256 * for later retrieval via /debugfs/tracing/latency_trace)
259 __update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
261 struct trace_array_cpu
*data
= tr
->data
[cpu
];
264 max_tr
.time_start
= data
->preempt_timestamp
;
266 data
= max_tr
.data
[cpu
];
267 data
->saved_latency
= tracing_max_latency
;
269 memcpy(data
->comm
, tsk
->comm
, TASK_COMM_LEN
);
270 data
->pid
= tsk
->pid
;
271 data
->uid
= tsk
->uid
;
272 data
->nice
= tsk
->static_prio
- 20 - MAX_RT_PRIO
;
273 data
->policy
= tsk
->policy
;
274 data
->rt_priority
= tsk
->rt_priority
;
276 /* record this tasks comm */
277 tracing_record_cmdline(current
);
280 #define CHECK_COND(cond) \
281 if (unlikely(cond)) { \
282 tracing_disabled = 1; \
288 * check_pages - integrity check of trace buffers
290 * As a safty measure we check to make sure the data pages have not
293 int check_pages(struct trace_array_cpu
*data
)
295 struct page
*page
, *tmp
;
297 CHECK_COND(data
->trace_pages
.next
->prev
!= &data
->trace_pages
);
298 CHECK_COND(data
->trace_pages
.prev
->next
!= &data
->trace_pages
);
300 list_for_each_entry_safe(page
, tmp
, &data
->trace_pages
, lru
) {
301 CHECK_COND(page
->lru
.next
->prev
!= &page
->lru
);
302 CHECK_COND(page
->lru
.prev
->next
!= &page
->lru
);
309 * head_page - page address of the first page in per_cpu buffer.
311 * head_page returns the page address of the first page in
312 * a per_cpu buffer. This also preforms various consistency
313 * checks to make sure the buffer has not been corrupted.
315 void *head_page(struct trace_array_cpu
*data
)
319 if (list_empty(&data
->trace_pages
))
322 page
= list_entry(data
->trace_pages
.next
, struct page
, lru
);
323 BUG_ON(&page
->lru
== &data
->trace_pages
);
325 return page_address(page
);
329 * trace_seq_printf - sequence printing of trace information
330 * @s: trace sequence descriptor
331 * @fmt: printf format string
333 * The tracer may use either sequence operations or its own
334 * copy to user routines. To simplify formating of a trace
335 * trace_seq_printf is used to store strings into a special
336 * buffer (@s). Then the output may be either used by
337 * the sequencer or pulled into another buffer.
340 trace_seq_printf(struct trace_seq
*s
, const char *fmt
, ...)
342 int len
= (PAGE_SIZE
- 1) - s
->len
;
350 ret
= vsnprintf(s
->buffer
+ s
->len
, len
, fmt
, ap
);
353 /* If we can't write it all, don't bother writing anything */
363 * trace_seq_puts - trace sequence printing of simple string
364 * @s: trace sequence descriptor
365 * @str: simple string to record
367 * The tracer may use either the sequence operations or its own
368 * copy to user routines. This function records a simple string
369 * into a special buffer (@s) for later retrieval by a sequencer
370 * or other mechanism.
373 trace_seq_puts(struct trace_seq
*s
, const char *str
)
375 int len
= strlen(str
);
377 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
380 memcpy(s
->buffer
+ s
->len
, str
, len
);
387 trace_seq_putc(struct trace_seq
*s
, unsigned char c
)
389 if (s
->len
>= (PAGE_SIZE
- 1))
392 s
->buffer
[s
->len
++] = c
;
398 trace_seq_putmem(struct trace_seq
*s
, void *mem
, size_t len
)
400 if (len
> ((PAGE_SIZE
- 1) - s
->len
))
403 memcpy(s
->buffer
+ s
->len
, mem
, len
);
410 static const char hex2asc
[] = "0123456789abcdef";
413 trace_seq_putmem_hex(struct trace_seq
*s
, void *mem
, size_t len
)
415 unsigned char hex
[HEX_CHARS
];
416 unsigned char *data
= mem
;
420 BUG_ON(len
>= HEX_CHARS
);
423 for (i
= 0, j
= 0; i
< len
; i
++) {
425 for (i
= len
-1, j
= 0; i
>= 0; i
--) {
429 hex
[j
++] = hex2asc
[byte
& 0x0f];
430 hex
[j
++] = hex2asc
[byte
>> 4];
434 return trace_seq_putmem(s
, hex
, j
);
438 trace_seq_reset(struct trace_seq
*s
)
444 ssize_t
trace_seq_to_user(struct trace_seq
*s
, char __user
*ubuf
, size_t cnt
)
449 if (s
->len
<= s
->readpos
)
452 len
= s
->len
- s
->readpos
;
455 ret
= copy_to_user(ubuf
, s
->buffer
+ s
->readpos
, cnt
);
464 trace_print_seq(struct seq_file
*m
, struct trace_seq
*s
)
466 int len
= s
->len
>= PAGE_SIZE
? PAGE_SIZE
- 1 : s
->len
;
469 seq_puts(m
, s
->buffer
);
475 * flip the trace buffers between two trace descriptors.
476 * This usually is the buffers between the global_trace and
477 * the max_tr to record a snapshot of a current trace.
479 * The ftrace_max_lock must be held.
482 flip_trace(struct trace_array_cpu
*tr1
, struct trace_array_cpu
*tr2
)
484 struct list_head flip_pages
;
486 INIT_LIST_HEAD(&flip_pages
);
488 memcpy(&tr1
->trace_head_idx
, &tr2
->trace_head_idx
,
489 sizeof(struct trace_array_cpu
) -
490 offsetof(struct trace_array_cpu
, trace_head_idx
));
494 list_splice_init(&tr1
->trace_pages
, &flip_pages
);
495 list_splice_init(&tr2
->trace_pages
, &tr1
->trace_pages
);
496 list_splice_init(&flip_pages
, &tr2
->trace_pages
);
497 BUG_ON(!list_empty(&flip_pages
));
503 * update_max_tr - snapshot all trace buffers from global_trace to max_tr
505 * @tsk: the task with the latency
506 * @cpu: The cpu that initiated the trace.
508 * Flip the buffers between the @tr and the max_tr and record information
509 * about which task was the cause of this latency.
512 update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
514 struct trace_array_cpu
*data
;
517 WARN_ON_ONCE(!irqs_disabled());
518 __raw_spin_lock(&ftrace_max_lock
);
519 /* clear out all the previous traces */
520 for_each_tracing_cpu(i
) {
522 flip_trace(max_tr
.data
[i
], data
);
526 __update_max_tr(tr
, tsk
, cpu
);
527 __raw_spin_unlock(&ftrace_max_lock
);
531 * update_max_tr_single - only copy one trace over, and reset the rest
533 * @tsk - task with the latency
534 * @cpu - the cpu of the buffer to copy.
536 * Flip the trace of a single CPU buffer between the @tr and the max_tr.
539 update_max_tr_single(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
541 struct trace_array_cpu
*data
= tr
->data
[cpu
];
544 WARN_ON_ONCE(!irqs_disabled());
545 __raw_spin_lock(&ftrace_max_lock
);
546 for_each_tracing_cpu(i
)
547 tracing_reset(max_tr
.data
[i
]);
549 flip_trace(max_tr
.data
[cpu
], data
);
552 __update_max_tr(tr
, tsk
, cpu
);
553 __raw_spin_unlock(&ftrace_max_lock
);
557 * register_tracer - register a tracer with the ftrace system.
558 * @type - the plugin for the tracer
560 * Register a new plugin tracer.
562 int register_tracer(struct tracer
*type
)
569 pr_info("Tracer must have a name\n");
573 mutex_lock(&trace_types_lock
);
574 for (t
= trace_types
; t
; t
= t
->next
) {
575 if (strcmp(type
->name
, t
->name
) == 0) {
577 pr_info("Trace %s already registered\n",
584 #ifdef CONFIG_FTRACE_STARTUP_TEST
585 if (type
->selftest
) {
586 struct tracer
*saved_tracer
= current_trace
;
587 struct trace_array_cpu
*data
;
588 struct trace_array
*tr
= &global_trace
;
589 int saved_ctrl
= tr
->ctrl
;
592 * Run a selftest on this tracer.
593 * Here we reset the trace buffer, and set the current
594 * tracer to be this tracer. The tracer can then run some
595 * internal tracing to verify that everything is in order.
596 * If we fail, we do not register this tracer.
598 for_each_tracing_cpu(i
) {
600 if (!head_page(data
))
604 current_trace
= type
;
606 /* the test is responsible for initializing and enabling */
607 pr_info("Testing tracer %s: ", type
->name
);
608 ret
= type
->selftest(type
, tr
);
609 /* the test is responsible for resetting too */
610 current_trace
= saved_tracer
;
611 tr
->ctrl
= saved_ctrl
;
613 printk(KERN_CONT
"FAILED!\n");
616 /* Only reset on passing, to avoid touching corrupted buffers */
617 for_each_tracing_cpu(i
) {
619 if (!head_page(data
))
623 printk(KERN_CONT
"PASSED\n");
627 type
->next
= trace_types
;
629 len
= strlen(type
->name
);
630 if (len
> max_tracer_type_len
)
631 max_tracer_type_len
= len
;
634 mutex_unlock(&trace_types_lock
);
639 void unregister_tracer(struct tracer
*type
)
644 mutex_lock(&trace_types_lock
);
645 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
649 pr_info("Trace %s not registered\n", type
->name
);
654 if (strlen(type
->name
) != max_tracer_type_len
)
657 max_tracer_type_len
= 0;
658 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
659 len
= strlen((*t
)->name
);
660 if (len
> max_tracer_type_len
)
661 max_tracer_type_len
= len
;
664 mutex_unlock(&trace_types_lock
);
667 void tracing_reset(struct trace_array_cpu
*data
)
671 data
->trace_head
= data
->trace_tail
= head_page(data
);
672 data
->trace_head_idx
= 0;
673 data
->trace_tail_idx
= 0;
676 #define SAVED_CMDLINES 128
677 static unsigned map_pid_to_cmdline
[PID_MAX_DEFAULT
+1];
678 static unsigned map_cmdline_to_pid
[SAVED_CMDLINES
];
679 static char saved_cmdlines
[SAVED_CMDLINES
][TASK_COMM_LEN
];
680 static int cmdline_idx
;
681 static DEFINE_SPINLOCK(trace_cmdline_lock
);
683 /* temporary disable recording */
684 atomic_t trace_record_cmdline_disabled __read_mostly
;
686 static void trace_init_cmdlines(void)
688 memset(&map_pid_to_cmdline
, -1, sizeof(map_pid_to_cmdline
));
689 memset(&map_cmdline_to_pid
, -1, sizeof(map_cmdline_to_pid
));
693 void trace_stop_cmdline_recording(void);
695 static void trace_save_cmdline(struct task_struct
*tsk
)
700 if (!tsk
->pid
|| unlikely(tsk
->pid
> PID_MAX_DEFAULT
))
704 * It's not the end of the world if we don't get
705 * the lock, but we also don't want to spin
706 * nor do we want to disable interrupts,
707 * so if we miss here, then better luck next time.
709 if (!spin_trylock(&trace_cmdline_lock
))
712 idx
= map_pid_to_cmdline
[tsk
->pid
];
713 if (idx
>= SAVED_CMDLINES
) {
714 idx
= (cmdline_idx
+ 1) % SAVED_CMDLINES
;
716 map
= map_cmdline_to_pid
[idx
];
717 if (map
<= PID_MAX_DEFAULT
)
718 map_pid_to_cmdline
[map
] = (unsigned)-1;
720 map_pid_to_cmdline
[tsk
->pid
] = idx
;
725 memcpy(&saved_cmdlines
[idx
], tsk
->comm
, TASK_COMM_LEN
);
727 spin_unlock(&trace_cmdline_lock
);
730 static char *trace_find_cmdline(int pid
)
732 char *cmdline
= "<...>";
738 if (pid
> PID_MAX_DEFAULT
)
741 map
= map_pid_to_cmdline
[pid
];
742 if (map
>= SAVED_CMDLINES
)
745 cmdline
= saved_cmdlines
[map
];
751 void tracing_record_cmdline(struct task_struct
*tsk
)
753 if (atomic_read(&trace_record_cmdline_disabled
))
756 trace_save_cmdline(tsk
);
759 static inline struct list_head
*
760 trace_next_list(struct trace_array_cpu
*data
, struct list_head
*next
)
763 * Roundrobin - but skip the head (which is not a real page):
766 if (unlikely(next
== &data
->trace_pages
))
768 BUG_ON(next
== &data
->trace_pages
);
774 trace_next_page(struct trace_array_cpu
*data
, void *addr
)
776 struct list_head
*next
;
779 page
= virt_to_page(addr
);
781 next
= trace_next_list(data
, &page
->lru
);
782 page
= list_entry(next
, struct page
, lru
);
784 return page_address(page
);
787 static inline struct trace_entry
*
788 tracing_get_trace_entry(struct trace_array
*tr
, struct trace_array_cpu
*data
)
790 unsigned long idx
, idx_next
;
791 struct trace_entry
*entry
;
794 idx
= data
->trace_head_idx
;
797 BUG_ON(idx
* TRACE_ENTRY_SIZE
>= PAGE_SIZE
);
799 entry
= data
->trace_head
+ idx
* TRACE_ENTRY_SIZE
;
801 if (unlikely(idx_next
>= ENTRIES_PER_PAGE
)) {
802 data
->trace_head
= trace_next_page(data
, data
->trace_head
);
806 if (data
->trace_head
== data
->trace_tail
&&
807 idx_next
== data
->trace_tail_idx
) {
810 data
->trace_tail_idx
++;
811 if (data
->trace_tail_idx
>= ENTRIES_PER_PAGE
) {
813 trace_next_page(data
, data
->trace_tail
);
814 data
->trace_tail_idx
= 0;
818 data
->trace_head_idx
= idx_next
;
824 tracing_generic_entry_update(struct trace_entry
*entry
, unsigned long flags
)
826 struct task_struct
*tsk
= current
;
829 pc
= preempt_count();
831 entry
->field
.preempt_count
= pc
& 0xff;
832 entry
->field
.pid
= (tsk
) ? tsk
->pid
: 0;
833 entry
->field
.t
= ftrace_now(raw_smp_processor_id());
835 (irqs_disabled_flags(flags
) ? TRACE_FLAG_IRQS_OFF
: 0) |
836 ((pc
& HARDIRQ_MASK
) ? TRACE_FLAG_HARDIRQ
: 0) |
837 ((pc
& SOFTIRQ_MASK
) ? TRACE_FLAG_SOFTIRQ
: 0) |
838 (need_resched() ? TRACE_FLAG_NEED_RESCHED
: 0);
842 trace_function(struct trace_array
*tr
, struct trace_array_cpu
*data
,
843 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
)
845 struct trace_entry
*entry
;
846 unsigned long irq_flags
;
848 raw_local_irq_save(irq_flags
);
849 __raw_spin_lock(&data
->lock
);
850 entry
= tracing_get_trace_entry(tr
, data
);
851 tracing_generic_entry_update(entry
, flags
);
852 entry
->type
= TRACE_FN
;
853 entry
->field
.fn
.ip
= ip
;
854 entry
->field
.fn
.parent_ip
= parent_ip
;
855 __raw_spin_unlock(&data
->lock
);
856 raw_local_irq_restore(irq_flags
);
860 ftrace(struct trace_array
*tr
, struct trace_array_cpu
*data
,
861 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
)
863 if (likely(!atomic_read(&data
->disabled
)))
864 trace_function(tr
, data
, ip
, parent_ip
, flags
);
867 #ifdef CONFIG_MMIOTRACE
868 void __trace_mmiotrace_rw(struct trace_array
*tr
, struct trace_array_cpu
*data
,
869 struct mmiotrace_rw
*rw
)
871 struct trace_entry
*entry
;
872 unsigned long irq_flags
;
874 raw_local_irq_save(irq_flags
);
875 __raw_spin_lock(&data
->lock
);
877 entry
= tracing_get_trace_entry(tr
, data
);
878 tracing_generic_entry_update(entry
, 0);
879 entry
->type
= TRACE_MMIO_RW
;
880 entry
->field
.mmiorw
= *rw
;
882 __raw_spin_unlock(&data
->lock
);
883 raw_local_irq_restore(irq_flags
);
888 void __trace_mmiotrace_map(struct trace_array
*tr
, struct trace_array_cpu
*data
,
889 struct mmiotrace_map
*map
)
891 struct trace_entry
*entry
;
892 unsigned long irq_flags
;
894 raw_local_irq_save(irq_flags
);
895 __raw_spin_lock(&data
->lock
);
897 entry
= tracing_get_trace_entry(tr
, data
);
898 tracing_generic_entry_update(entry
, 0);
899 entry
->type
= TRACE_MMIO_MAP
;
900 entry
->field
.mmiomap
= *map
;
902 __raw_spin_unlock(&data
->lock
);
903 raw_local_irq_restore(irq_flags
);
909 void __trace_stack(struct trace_array
*tr
,
910 struct trace_array_cpu
*data
,
914 struct trace_entry
*entry
;
915 struct stack_trace trace
;
917 if (!(trace_flags
& TRACE_ITER_STACKTRACE
))
920 entry
= tracing_get_trace_entry(tr
, data
);
921 tracing_generic_entry_update(entry
, flags
);
922 entry
->type
= TRACE_STACK
;
924 memset(&entry
->field
.stack
, 0, sizeof(entry
->field
.stack
));
926 trace
.nr_entries
= 0;
927 trace
.max_entries
= FTRACE_STACK_ENTRIES
;
929 trace
.entries
= entry
->field
.stack
.caller
;
931 save_stack_trace(&trace
);
935 __trace_special(void *__tr
, void *__data
,
936 unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
938 struct trace_array_cpu
*data
= __data
;
939 struct trace_array
*tr
= __tr
;
940 struct trace_entry
*entry
;
941 unsigned long irq_flags
;
943 raw_local_irq_save(irq_flags
);
944 __raw_spin_lock(&data
->lock
);
945 entry
= tracing_get_trace_entry(tr
, data
);
946 tracing_generic_entry_update(entry
, 0);
947 entry
->type
= TRACE_SPECIAL
;
948 entry
->field
.special
.arg1
= arg1
;
949 entry
->field
.special
.arg2
= arg2
;
950 entry
->field
.special
.arg3
= arg3
;
951 __trace_stack(tr
, data
, irq_flags
, 4);
952 __raw_spin_unlock(&data
->lock
);
953 raw_local_irq_restore(irq_flags
);
959 tracing_sched_switch_trace(struct trace_array
*tr
,
960 struct trace_array_cpu
*data
,
961 struct task_struct
*prev
,
962 struct task_struct
*next
,
965 struct trace_entry
*entry
;
966 unsigned long irq_flags
;
968 raw_local_irq_save(irq_flags
);
969 __raw_spin_lock(&data
->lock
);
970 entry
= tracing_get_trace_entry(tr
, data
);
971 tracing_generic_entry_update(entry
, flags
);
972 entry
->type
= TRACE_CTX
;
973 entry
->field
.ctx
.prev_pid
= prev
->pid
;
974 entry
->field
.ctx
.prev_prio
= prev
->prio
;
975 entry
->field
.ctx
.prev_state
= prev
->state
;
976 entry
->field
.ctx
.next_pid
= next
->pid
;
977 entry
->field
.ctx
.next_prio
= next
->prio
;
978 entry
->field
.ctx
.next_state
= next
->state
;
979 __trace_stack(tr
, data
, flags
, 5);
980 __raw_spin_unlock(&data
->lock
);
981 raw_local_irq_restore(irq_flags
);
985 tracing_sched_wakeup_trace(struct trace_array
*tr
,
986 struct trace_array_cpu
*data
,
987 struct task_struct
*wakee
,
988 struct task_struct
*curr
,
991 struct trace_entry
*entry
;
992 unsigned long irq_flags
;
994 raw_local_irq_save(irq_flags
);
995 __raw_spin_lock(&data
->lock
);
996 entry
= tracing_get_trace_entry(tr
, data
);
997 tracing_generic_entry_update(entry
, flags
);
998 entry
->type
= TRACE_WAKE
;
999 entry
->field
.ctx
.prev_pid
= curr
->pid
;
1000 entry
->field
.ctx
.prev_prio
= curr
->prio
;
1001 entry
->field
.ctx
.prev_state
= curr
->state
;
1002 entry
->field
.ctx
.next_pid
= wakee
->pid
;
1003 entry
->field
.ctx
.next_prio
= wakee
->prio
;
1004 entry
->field
.ctx
.next_state
= wakee
->state
;
1005 __trace_stack(tr
, data
, flags
, 6);
1006 __raw_spin_unlock(&data
->lock
);
1007 raw_local_irq_restore(irq_flags
);
1013 ftrace_special(unsigned long arg1
, unsigned long arg2
, unsigned long arg3
)
1015 struct trace_array
*tr
= &global_trace
;
1016 struct trace_array_cpu
*data
;
1017 unsigned long flags
;
1021 if (tracing_disabled
|| current_trace
== &no_tracer
|| !tr
->ctrl
)
1024 local_irq_save(flags
);
1025 cpu
= raw_smp_processor_id();
1026 data
= tr
->data
[cpu
];
1027 disabled
= atomic_inc_return(&data
->disabled
);
1029 if (likely(disabled
== 1))
1030 __trace_special(tr
, data
, arg1
, arg2
, arg3
);
1032 atomic_dec(&data
->disabled
);
1033 local_irq_restore(flags
);
1036 #ifdef CONFIG_FTRACE
1038 function_trace_call(unsigned long ip
, unsigned long parent_ip
)
1040 struct trace_array
*tr
= &global_trace
;
1041 struct trace_array_cpu
*data
;
1042 unsigned long flags
;
1046 if (unlikely(!ftrace_function_enabled
))
1052 local_irq_save(flags
);
1053 cpu
= raw_smp_processor_id();
1054 data
= tr
->data
[cpu
];
1055 disabled
= atomic_inc_return(&data
->disabled
);
1057 if (likely(disabled
== 1))
1058 trace_function(tr
, data
, ip
, parent_ip
, flags
);
1060 atomic_dec(&data
->disabled
);
1061 local_irq_restore(flags
);
1064 static struct ftrace_ops trace_ops __read_mostly
=
1066 .func
= function_trace_call
,
1069 void tracing_start_function_trace(void)
1071 ftrace_function_enabled
= 0;
1072 register_ftrace_function(&trace_ops
);
1074 ftrace_function_enabled
= 1;
1077 void tracing_stop_function_trace(void)
1079 ftrace_function_enabled
= 0;
1080 unregister_ftrace_function(&trace_ops
);
1084 enum trace_file_type
{
1085 TRACE_FILE_LAT_FMT
= 1,
1088 /* Return the current entry. */
1089 static struct trace_entry
*
1090 trace_entry_idx(struct trace_array
*tr
, struct trace_array_cpu
*data
,
1091 struct trace_iterator
*iter
, int cpu
)
1094 struct trace_entry
*array
;
1096 if (iter
->next_idx
[cpu
] >= tr
->entries
||
1097 iter
->next_idx
[cpu
] >= data
->trace_idx
||
1098 (data
->trace_head
== data
->trace_tail
&&
1099 data
->trace_head_idx
== data
->trace_tail_idx
))
1102 if (!iter
->next_page
[cpu
]) {
1103 /* Initialize the iterator for this cpu trace buffer */
1104 WARN_ON(!data
->trace_tail
);
1105 page
= virt_to_page(data
->trace_tail
);
1106 iter
->next_page
[cpu
] = &page
->lru
;
1107 iter
->next_page_idx
[cpu
] = data
->trace_tail_idx
;
1110 page
= list_entry(iter
->next_page
[cpu
], struct page
, lru
);
1111 BUG_ON(&data
->trace_pages
== &page
->lru
);
1113 array
= page_address(page
);
1115 WARN_ON(iter
->next_page_idx
[cpu
] >= ENTRIES_PER_PAGE
);
1116 return &array
[iter
->next_page_idx
[cpu
]];
1119 /* Increment the index counter of an iterator by one */
1120 static void trace_iterator_increment(struct trace_iterator
*iter
, int cpu
)
1123 iter
->next_idx
[cpu
]++;
1124 iter
->next_page_idx
[cpu
]++;
1126 if (iter
->next_page_idx
[cpu
] >= ENTRIES_PER_PAGE
) {
1127 struct trace_array_cpu
*data
= iter
->tr
->data
[cpu
];
1129 iter
->next_page_idx
[cpu
] = 0;
1130 iter
->next_page
[cpu
] =
1131 trace_next_list(data
, iter
->next_page
[cpu
]);
1135 static struct trace_entry
*
1136 trace_entry_next(struct trace_array
*tr
, struct trace_array_cpu
*data
,
1137 struct trace_iterator
*iter
, int cpu
)
1139 struct list_head
*next_page
;
1140 struct trace_entry
*ent
;
1141 int idx
, next_idx
, next_page_idx
;
1143 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1145 if (likely(!ent
|| ent
->type
!= TRACE_CONT
))
1148 /* save the iterator details */
1150 next_idx
= iter
->next_idx
[cpu
];
1151 next_page_idx
= iter
->next_page_idx
[cpu
];
1152 next_page
= iter
->next_page
[cpu
];
1154 /* find a real entry */
1156 trace_iterator_increment(iter
, cpu
);
1157 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1158 } while (ent
&& ent
->type
!= TRACE_CONT
);
1160 /* reset the iterator */
1162 iter
->next_idx
[cpu
] = next_idx
;
1163 iter
->next_page_idx
[cpu
] = next_page_idx
;
1164 iter
->next_page
[cpu
] = next_page
;
1169 static struct trace_entry
*
1170 __find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
, int inc
)
1172 struct trace_array
*tr
= iter
->tr
;
1173 struct trace_entry
*ent
, *next
= NULL
;
1177 for_each_tracing_cpu(cpu
) {
1178 if (!head_page(tr
->data
[cpu
]))
1181 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
1183 if (ent
&& ent
->type
== TRACE_CONT
) {
1184 struct trace_array_cpu
*data
= tr
->data
[cpu
];
1187 ent
= trace_entry_next(tr
, data
, iter
, cpu
);
1189 while (ent
&& ent
->type
== TRACE_CONT
) {
1190 trace_iterator_increment(iter
, cpu
);
1191 ent
= trace_entry_idx(tr
, tr
->data
[cpu
],
1198 * Pick the entry with the smallest timestamp:
1200 if (ent
&& (!next
|| ent
->field
.t
< next
->field
.t
)) {
1207 *ent_cpu
= next_cpu
;
1212 /* Find the next real entry, without updating the iterator itself */
1213 static struct trace_entry
*
1214 find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
)
1216 return __find_next_entry(iter
, ent_cpu
, 0);
1219 /* Find the next real entry, and increment the iterator to the next entry */
1220 static void *find_next_entry_inc(struct trace_iterator
*iter
)
1222 struct trace_entry
*next
;
1225 next
= __find_next_entry(iter
, &next_cpu
, 1);
1227 iter
->prev_ent
= iter
->ent
;
1228 iter
->prev_cpu
= iter
->cpu
;
1231 iter
->cpu
= next_cpu
;
1234 trace_iterator_increment(iter
, iter
->cpu
);
1236 return next
? iter
: NULL
;
1239 static void trace_consume(struct trace_iterator
*iter
)
1241 struct trace_array_cpu
*data
= iter
->tr
->data
[iter
->cpu
];
1242 struct trace_entry
*ent
;
1245 data
->trace_tail_idx
++;
1246 if (data
->trace_tail_idx
>= ENTRIES_PER_PAGE
) {
1247 data
->trace_tail
= trace_next_page(data
, data
->trace_tail
);
1248 data
->trace_tail_idx
= 0;
1251 /* Check if we empty it, then reset the index */
1252 if (data
->trace_head
== data
->trace_tail
&&
1253 data
->trace_head_idx
== data
->trace_tail_idx
)
1254 data
->trace_idx
= 0;
1256 ent
= trace_entry_idx(iter
->tr
, iter
->tr
->data
[iter
->cpu
],
1258 if (ent
&& ent
->type
== TRACE_CONT
)
1262 static void *s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1264 struct trace_iterator
*iter
= m
->private;
1270 /* can't go backwards */
1275 ent
= find_next_entry_inc(iter
);
1279 while (ent
&& iter
->idx
< i
)
1280 ent
= find_next_entry_inc(iter
);
1287 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
1289 struct trace_iterator
*iter
= m
->private;
1294 mutex_lock(&trace_types_lock
);
1296 if (!current_trace
|| current_trace
!= iter
->trace
) {
1297 mutex_unlock(&trace_types_lock
);
1301 atomic_inc(&trace_record_cmdline_disabled
);
1303 /* let the tracer grab locks here if needed */
1304 if (current_trace
->start
)
1305 current_trace
->start(iter
);
1307 if (*pos
!= iter
->pos
) {
1311 iter
->prev_ent
= NULL
;
1312 iter
->prev_cpu
= -1;
1314 for_each_tracing_cpu(i
) {
1315 iter
->next_idx
[i
] = 0;
1316 iter
->next_page
[i
] = NULL
;
1319 for (p
= iter
; p
&& l
< *pos
; p
= s_next(m
, p
, &l
))
1324 p
= s_next(m
, p
, &l
);
1330 static void s_stop(struct seq_file
*m
, void *p
)
1332 struct trace_iterator
*iter
= m
->private;
1334 atomic_dec(&trace_record_cmdline_disabled
);
1336 /* let the tracer release locks here if needed */
1337 if (current_trace
&& current_trace
== iter
->trace
&& iter
->trace
->stop
)
1338 iter
->trace
->stop(iter
);
1340 mutex_unlock(&trace_types_lock
);
1343 #define KRETPROBE_MSG "[unknown/kretprobe'd]"
1345 #ifdef CONFIG_KRETPROBES
1346 static inline int kretprobed(unsigned long addr
)
1348 return addr
== (unsigned long)kretprobe_trampoline
;
1351 static inline int kretprobed(unsigned long addr
)
1355 #endif /* CONFIG_KRETPROBES */
1358 seq_print_sym_short(struct trace_seq
*s
, const char *fmt
, unsigned long address
)
1360 #ifdef CONFIG_KALLSYMS
1361 char str
[KSYM_SYMBOL_LEN
];
1363 kallsyms_lookup(address
, NULL
, NULL
, NULL
, str
);
1365 return trace_seq_printf(s
, fmt
, str
);
1371 seq_print_sym_offset(struct trace_seq
*s
, const char *fmt
,
1372 unsigned long address
)
1374 #ifdef CONFIG_KALLSYMS
1375 char str
[KSYM_SYMBOL_LEN
];
1377 sprint_symbol(str
, address
);
1378 return trace_seq_printf(s
, fmt
, str
);
1383 #ifndef CONFIG_64BIT
1384 # define IP_FMT "%08lx"
1386 # define IP_FMT "%016lx"
1390 seq_print_ip_sym(struct trace_seq
*s
, unsigned long ip
, unsigned long sym_flags
)
1395 return trace_seq_printf(s
, "0");
1397 if (sym_flags
& TRACE_ITER_SYM_OFFSET
)
1398 ret
= seq_print_sym_offset(s
, "%s", ip
);
1400 ret
= seq_print_sym_short(s
, "%s", ip
);
1405 if (sym_flags
& TRACE_ITER_SYM_ADDR
)
1406 ret
= trace_seq_printf(s
, " <" IP_FMT
">", ip
);
1410 static void print_lat_help_header(struct seq_file
*m
)
1412 seq_puts(m
, "# _------=> CPU# \n");
1413 seq_puts(m
, "# / _-----=> irqs-off \n");
1414 seq_puts(m
, "# | / _----=> need-resched \n");
1415 seq_puts(m
, "# || / _---=> hardirq/softirq \n");
1416 seq_puts(m
, "# ||| / _--=> preempt-depth \n");
1417 seq_puts(m
, "# |||| / \n");
1418 seq_puts(m
, "# ||||| delay \n");
1419 seq_puts(m
, "# cmd pid ||||| time | caller \n");
1420 seq_puts(m
, "# \\ / ||||| \\ | / \n");
1423 static void print_func_help_header(struct seq_file
*m
)
1425 seq_puts(m
, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
1426 seq_puts(m
, "# | | | | |\n");
1431 print_trace_header(struct seq_file
*m
, struct trace_iterator
*iter
)
1433 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1434 struct trace_array
*tr
= iter
->tr
;
1435 struct trace_array_cpu
*data
= tr
->data
[tr
->cpu
];
1436 struct tracer
*type
= current_trace
;
1437 unsigned long total
= 0;
1438 unsigned long entries
= 0;
1440 const char *name
= "preemption";
1445 for_each_tracing_cpu(cpu
) {
1446 if (head_page(tr
->data
[cpu
])) {
1447 total
+= tr
->data
[cpu
]->trace_idx
;
1448 if (tr
->data
[cpu
]->trace_idx
> tr
->entries
)
1449 entries
+= tr
->entries
;
1451 entries
+= tr
->data
[cpu
]->trace_idx
;
1455 seq_printf(m
, "%s latency trace v1.1.5 on %s\n",
1457 seq_puts(m
, "-----------------------------------"
1458 "---------------------------------\n");
1459 seq_printf(m
, " latency: %lu us, #%lu/%lu, CPU#%d |"
1460 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
1461 nsecs_to_usecs(data
->saved_latency
),
1465 #if defined(CONFIG_PREEMPT_NONE)
1467 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
1469 #elif defined(CONFIG_PREEMPT)
1474 /* These are reserved for later use */
1477 seq_printf(m
, " #P:%d)\n", num_online_cpus());
1481 seq_puts(m
, " -----------------\n");
1482 seq_printf(m
, " | task: %.16s-%d "
1483 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
1484 data
->comm
, data
->pid
, data
->uid
, data
->nice
,
1485 data
->policy
, data
->rt_priority
);
1486 seq_puts(m
, " -----------------\n");
1488 if (data
->critical_start
) {
1489 seq_puts(m
, " => started at: ");
1490 seq_print_ip_sym(&iter
->seq
, data
->critical_start
, sym_flags
);
1491 trace_print_seq(m
, &iter
->seq
);
1492 seq_puts(m
, "\n => ended at: ");
1493 seq_print_ip_sym(&iter
->seq
, data
->critical_end
, sym_flags
);
1494 trace_print_seq(m
, &iter
->seq
);
1502 lat_print_generic(struct trace_seq
*s
, struct trace_entry
*entry
, int cpu
)
1504 struct trace_field
*field
= &entry
->field
;
1505 int hardirq
, softirq
;
1508 comm
= trace_find_cmdline(field
->pid
);
1510 trace_seq_printf(s
, "%8.8s-%-5d ", comm
, field
->pid
);
1511 trace_seq_printf(s
, "%3d", cpu
);
1512 trace_seq_printf(s
, "%c%c",
1513 (field
->flags
& TRACE_FLAG_IRQS_OFF
) ? 'd' : '.',
1514 ((field
->flags
& TRACE_FLAG_NEED_RESCHED
) ? 'N' : '.'));
1516 hardirq
= field
->flags
& TRACE_FLAG_HARDIRQ
;
1517 softirq
= field
->flags
& TRACE_FLAG_SOFTIRQ
;
1518 if (hardirq
&& softirq
) {
1519 trace_seq_putc(s
, 'H');
1522 trace_seq_putc(s
, 'h');
1525 trace_seq_putc(s
, 's');
1527 trace_seq_putc(s
, '.');
1531 if (field
->preempt_count
)
1532 trace_seq_printf(s
, "%x", field
->preempt_count
);
1534 trace_seq_puts(s
, ".");
1537 unsigned long preempt_mark_thresh
= 100;
1540 lat_print_timestamp(struct trace_seq
*s
, unsigned long long abs_usecs
,
1541 unsigned long rel_usecs
)
1543 trace_seq_printf(s
, " %4lldus", abs_usecs
);
1544 if (rel_usecs
> preempt_mark_thresh
)
1545 trace_seq_puts(s
, "!: ");
1546 else if (rel_usecs
> 1)
1547 trace_seq_puts(s
, "+: ");
1549 trace_seq_puts(s
, " : ");
1552 static const char state_to_char
[] = TASK_STATE_TO_CHAR_STR
;
1555 trace_seq_print_cont(struct trace_seq
*s
, struct trace_iterator
*iter
)
1557 struct trace_array
*tr
= iter
->tr
;
1558 struct trace_array_cpu
*data
= tr
->data
[iter
->cpu
];
1559 struct trace_entry
*ent
;
1561 ent
= trace_entry_idx(tr
, data
, iter
, iter
->cpu
);
1562 if (!ent
|| ent
->type
!= TRACE_CONT
) {
1563 trace_seq_putc(s
, '\n');
1568 trace_seq_printf(s
, "%s", ent
->cont
.buf
);
1569 trace_iterator_increment(iter
, iter
->cpu
);
1570 ent
= trace_entry_idx(tr
, data
, iter
, iter
->cpu
);
1571 } while (ent
&& ent
->type
== TRACE_CONT
);
1575 print_lat_fmt(struct trace_iterator
*iter
, unsigned int trace_idx
, int cpu
)
1577 struct trace_seq
*s
= &iter
->seq
;
1578 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1579 struct trace_entry
*next_entry
= find_next_entry(iter
, NULL
);
1580 unsigned long verbose
= (trace_flags
& TRACE_ITER_VERBOSE
);
1581 struct trace_entry
*entry
= iter
->ent
;
1582 struct trace_field
*field
= &entry
->field
;
1583 unsigned long abs_usecs
;
1584 unsigned long rel_usecs
;
1593 if (entry
->type
== TRACE_CONT
)
1596 rel_usecs
= ns2usecs(next_entry
->field
.t
- entry
->field
.t
);
1597 abs_usecs
= ns2usecs(entry
->field
.t
- iter
->tr
->time_start
);
1600 comm
= trace_find_cmdline(field
->pid
);
1601 trace_seq_printf(s
, "%16s %5d %3d %d %08x %08x [%08lx]"
1602 " %ld.%03ldms (+%ld.%03ldms): ",
1604 field
->pid
, cpu
, field
->flags
,
1605 field
->preempt_count
, trace_idx
,
1608 abs_usecs
% 1000, rel_usecs
/1000,
1611 lat_print_generic(s
, entry
, cpu
);
1612 lat_print_timestamp(s
, abs_usecs
, rel_usecs
);
1614 switch (entry
->type
) {
1616 seq_print_ip_sym(s
, field
->fn
.ip
, sym_flags
);
1617 trace_seq_puts(s
, " (");
1618 if (kretprobed(field
->fn
.parent_ip
))
1619 trace_seq_puts(s
, KRETPROBE_MSG
);
1621 seq_print_ip_sym(s
, field
->fn
.parent_ip
, sym_flags
);
1622 trace_seq_puts(s
, ")\n");
1626 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1627 state_to_char
[field
->ctx
.next_state
] : 'X';
1629 state
= field
->ctx
.prev_state
?
1630 __ffs(field
->ctx
.prev_state
) + 1 : 0;
1631 S
= state
< sizeof(state_to_char
) - 1 ? state_to_char
[state
] : 'X';
1632 comm
= trace_find_cmdline(field
->ctx
.next_pid
);
1633 trace_seq_printf(s
, " %5d:%3d:%c %s %5d:%3d:%c %s\n",
1634 field
->ctx
.prev_pid
,
1635 field
->ctx
.prev_prio
,
1636 S
, entry
->type
== TRACE_CTX
? "==>" : " +",
1637 field
->ctx
.next_pid
,
1638 field
->ctx
.next_prio
,
1642 trace_seq_printf(s
, "# %ld %ld %ld\n",
1643 field
->special
.arg1
,
1644 field
->special
.arg2
,
1645 field
->special
.arg3
);
1648 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1650 trace_seq_puts(s
, " <= ");
1651 seq_print_ip_sym(s
, field
->stack
.caller
[i
], sym_flags
);
1653 trace_seq_puts(s
, "\n");
1656 seq_print_ip_sym(s
, field
->print
.ip
, sym_flags
);
1657 trace_seq_printf(s
, ": %s", field
->print
.buf
);
1658 if (field
->flags
&& TRACE_FLAG_CONT
)
1659 trace_seq_print_cont(s
, iter
);
1662 trace_seq_printf(s
, "Unknown type %d\n", entry
->type
);
1667 static int print_trace_fmt(struct trace_iterator
*iter
)
1669 struct trace_seq
*s
= &iter
->seq
;
1670 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1671 struct trace_entry
*entry
;
1672 struct trace_field
*field
;
1673 unsigned long usec_rem
;
1674 unsigned long long t
;
1683 if (entry
->type
== TRACE_CONT
)
1686 field
= &entry
->field
;
1688 comm
= trace_find_cmdline(iter
->ent
->field
.pid
);
1690 t
= ns2usecs(field
->t
);
1691 usec_rem
= do_div(t
, 1000000ULL);
1692 secs
= (unsigned long)t
;
1694 ret
= trace_seq_printf(s
, "%16s-%-5d ", comm
, field
->pid
);
1697 ret
= trace_seq_printf(s
, "[%03d] ", iter
->cpu
);
1700 ret
= trace_seq_printf(s
, "%5lu.%06lu: ", secs
, usec_rem
);
1704 switch (entry
->type
) {
1706 ret
= seq_print_ip_sym(s
, field
->fn
.ip
, sym_flags
);
1709 if ((sym_flags
& TRACE_ITER_PRINT_PARENT
) &&
1710 field
->fn
.parent_ip
) {
1711 ret
= trace_seq_printf(s
, " <-");
1714 if (kretprobed(field
->fn
.parent_ip
))
1715 ret
= trace_seq_puts(s
, KRETPROBE_MSG
);
1717 ret
= seq_print_ip_sym(s
,
1718 field
->fn
.parent_ip
,
1723 ret
= trace_seq_printf(s
, "\n");
1729 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1730 state_to_char
[field
->ctx
.prev_state
] : 'X';
1731 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1732 state_to_char
[field
->ctx
.next_state
] : 'X';
1733 ret
= trace_seq_printf(s
, " %5d:%3d:%c %s %5d:%3d:%c\n",
1734 field
->ctx
.prev_pid
,
1735 field
->ctx
.prev_prio
,
1737 entry
->type
== TRACE_CTX
? "==>" : " +",
1738 field
->ctx
.next_pid
,
1739 field
->ctx
.next_prio
,
1745 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
1746 field
->special
.arg1
,
1747 field
->special
.arg2
,
1748 field
->special
.arg3
);
1753 for (i
= 0; i
< FTRACE_STACK_ENTRIES
; i
++) {
1755 ret
= trace_seq_puts(s
, " <= ");
1759 ret
= seq_print_ip_sym(s
, field
->stack
.caller
[i
],
1764 ret
= trace_seq_puts(s
, "\n");
1769 seq_print_ip_sym(s
, field
->print
.ip
, sym_flags
);
1770 trace_seq_printf(s
, ": %s", field
->print
.buf
);
1771 if (field
->flags
&& TRACE_FLAG_CONT
)
1772 trace_seq_print_cont(s
, iter
);
1778 static int print_raw_fmt(struct trace_iterator
*iter
)
1780 struct trace_seq
*s
= &iter
->seq
;
1781 struct trace_entry
*entry
;
1782 struct trace_field
*field
;
1788 if (entry
->type
== TRACE_CONT
)
1791 field
= &entry
->field
;
1793 ret
= trace_seq_printf(s
, "%d %d %llu ",
1794 field
->pid
, iter
->cpu
, field
->t
);
1798 switch (entry
->type
) {
1800 ret
= trace_seq_printf(s
, "%x %x\n",
1802 field
->fn
.parent_ip
);
1808 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1809 state_to_char
[field
->ctx
.prev_state
] : 'X';
1810 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1811 state_to_char
[field
->ctx
.next_state
] : 'X';
1812 if (entry
->type
== TRACE_WAKE
)
1814 ret
= trace_seq_printf(s
, "%d %d %c %d %d %c\n",
1815 field
->ctx
.prev_pid
,
1816 field
->ctx
.prev_prio
,
1818 field
->ctx
.next_pid
,
1819 field
->ctx
.next_prio
,
1826 ret
= trace_seq_printf(s
, "# %ld %ld %ld\n",
1827 field
->special
.arg1
,
1828 field
->special
.arg2
,
1829 field
->special
.arg3
);
1834 trace_seq_printf(s
, "# %lx %s",
1835 field
->print
.ip
, field
->print
.buf
);
1836 if (field
->flags
&& TRACE_FLAG_CONT
)
1837 trace_seq_print_cont(s
, iter
);
1843 #define SEQ_PUT_FIELD_RET(s, x) \
1845 if (!trace_seq_putmem(s, &(x), sizeof(x))) \
1849 #define SEQ_PUT_HEX_FIELD_RET(s, x) \
1851 if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
1855 static int print_hex_fmt(struct trace_iterator
*iter
)
1857 struct trace_seq
*s
= &iter
->seq
;
1858 unsigned char newline
= '\n';
1859 struct trace_entry
*entry
;
1860 struct trace_field
*field
;
1865 if (entry
->type
== TRACE_CONT
)
1868 field
= &entry
->field
;
1870 SEQ_PUT_HEX_FIELD_RET(s
, field
->pid
);
1871 SEQ_PUT_HEX_FIELD_RET(s
, iter
->cpu
);
1872 SEQ_PUT_HEX_FIELD_RET(s
, field
->t
);
1874 switch (entry
->type
) {
1876 SEQ_PUT_HEX_FIELD_RET(s
, field
->fn
.ip
);
1877 SEQ_PUT_HEX_FIELD_RET(s
, field
->fn
.parent_ip
);
1881 S
= field
->ctx
.prev_state
< sizeof(state_to_char
) ?
1882 state_to_char
[field
->ctx
.prev_state
] : 'X';
1883 T
= field
->ctx
.next_state
< sizeof(state_to_char
) ?
1884 state_to_char
[field
->ctx
.next_state
] : 'X';
1885 if (entry
->type
== TRACE_WAKE
)
1887 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.prev_pid
);
1888 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.prev_prio
);
1889 SEQ_PUT_HEX_FIELD_RET(s
, S
);
1890 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.next_pid
);
1891 SEQ_PUT_HEX_FIELD_RET(s
, field
->ctx
.next_prio
);
1892 SEQ_PUT_HEX_FIELD_RET(s
, T
);
1896 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg1
);
1897 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg2
);
1898 SEQ_PUT_HEX_FIELD_RET(s
, field
->special
.arg3
);
1901 SEQ_PUT_FIELD_RET(s
, newline
);
1906 static int print_bin_fmt(struct trace_iterator
*iter
)
1908 struct trace_seq
*s
= &iter
->seq
;
1909 struct trace_entry
*entry
;
1910 struct trace_field
*field
;
1914 if (entry
->type
== TRACE_CONT
)
1917 field
= &entry
->field
;
1919 SEQ_PUT_FIELD_RET(s
, field
->pid
);
1920 SEQ_PUT_FIELD_RET(s
, field
->cpu
);
1921 SEQ_PUT_FIELD_RET(s
, field
->t
);
1923 switch (entry
->type
) {
1925 SEQ_PUT_FIELD_RET(s
, field
->fn
.ip
);
1926 SEQ_PUT_FIELD_RET(s
, field
->fn
.parent_ip
);
1929 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_pid
);
1930 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_prio
);
1931 SEQ_PUT_FIELD_RET(s
, field
->ctx
.prev_state
);
1932 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_pid
);
1933 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_prio
);
1934 SEQ_PUT_FIELD_RET(s
, field
->ctx
.next_state
);
1938 SEQ_PUT_FIELD_RET(s
, field
->special
.arg1
);
1939 SEQ_PUT_FIELD_RET(s
, field
->special
.arg2
);
1940 SEQ_PUT_FIELD_RET(s
, field
->special
.arg3
);
1946 static int trace_empty(struct trace_iterator
*iter
)
1948 struct trace_array_cpu
*data
;
1951 for_each_tracing_cpu(cpu
) {
1952 data
= iter
->tr
->data
[cpu
];
1954 if (head_page(data
) && data
->trace_idx
&&
1955 (data
->trace_tail
!= data
->trace_head
||
1956 data
->trace_tail_idx
!= data
->trace_head_idx
))
1962 static int print_trace_line(struct trace_iterator
*iter
)
1964 if (iter
->trace
&& iter
->trace
->print_line
)
1965 return iter
->trace
->print_line(iter
);
1967 if (trace_flags
& TRACE_ITER_BIN
)
1968 return print_bin_fmt(iter
);
1970 if (trace_flags
& TRACE_ITER_HEX
)
1971 return print_hex_fmt(iter
);
1973 if (trace_flags
& TRACE_ITER_RAW
)
1974 return print_raw_fmt(iter
);
1976 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
)
1977 return print_lat_fmt(iter
, iter
->idx
, iter
->cpu
);
1979 return print_trace_fmt(iter
);
1982 static int s_show(struct seq_file
*m
, void *v
)
1984 struct trace_iterator
*iter
= v
;
1986 if (iter
->ent
== NULL
) {
1988 seq_printf(m
, "# tracer: %s\n", iter
->trace
->name
);
1991 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
) {
1992 /* print nothing if the buffers are empty */
1993 if (trace_empty(iter
))
1995 print_trace_header(m
, iter
);
1996 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
1997 print_lat_help_header(m
);
1999 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
2000 print_func_help_header(m
);
2003 print_trace_line(iter
);
2004 trace_print_seq(m
, &iter
->seq
);
2010 static struct seq_operations tracer_seq_ops
= {
2017 static struct trace_iterator
*
2018 __tracing_open(struct inode
*inode
, struct file
*file
, int *ret
)
2020 struct trace_iterator
*iter
;
2022 if (tracing_disabled
) {
2027 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2033 mutex_lock(&trace_types_lock
);
2034 if (current_trace
&& current_trace
->print_max
)
2037 iter
->tr
= inode
->i_private
;
2038 iter
->trace
= current_trace
;
2041 /* TODO stop tracer */
2042 *ret
= seq_open(file
, &tracer_seq_ops
);
2044 struct seq_file
*m
= file
->private_data
;
2047 /* stop the trace while dumping */
2048 if (iter
->tr
->ctrl
) {
2050 ftrace_function_enabled
= 0;
2053 if (iter
->trace
&& iter
->trace
->open
)
2054 iter
->trace
->open(iter
);
2059 mutex_unlock(&trace_types_lock
);
2065 int tracing_open_generic(struct inode
*inode
, struct file
*filp
)
2067 if (tracing_disabled
)
2070 filp
->private_data
= inode
->i_private
;
2074 int tracing_release(struct inode
*inode
, struct file
*file
)
2076 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
2077 struct trace_iterator
*iter
= m
->private;
2079 mutex_lock(&trace_types_lock
);
2080 if (iter
->trace
&& iter
->trace
->close
)
2081 iter
->trace
->close(iter
);
2083 /* reenable tracing if it was previously enabled */
2084 if (iter
->tr
->ctrl
) {
2087 * It is safe to enable function tracing even if it
2090 ftrace_function_enabled
= 1;
2092 mutex_unlock(&trace_types_lock
);
2094 seq_release(inode
, file
);
2099 static int tracing_open(struct inode
*inode
, struct file
*file
)
2103 __tracing_open(inode
, file
, &ret
);
2108 static int tracing_lt_open(struct inode
*inode
, struct file
*file
)
2110 struct trace_iterator
*iter
;
2113 iter
= __tracing_open(inode
, file
, &ret
);
2116 iter
->iter_flags
|= TRACE_FILE_LAT_FMT
;
2123 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
2125 struct tracer
*t
= m
->private;
2137 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
2139 struct tracer
*t
= m
->private;
2142 mutex_lock(&trace_types_lock
);
2143 for (; t
&& l
< *pos
; t
= t_next(m
, t
, &l
))
2149 static void t_stop(struct seq_file
*m
, void *p
)
2151 mutex_unlock(&trace_types_lock
);
2154 static int t_show(struct seq_file
*m
, void *v
)
2156 struct tracer
*t
= v
;
2161 seq_printf(m
, "%s", t
->name
);
2170 static struct seq_operations show_traces_seq_ops
= {
2177 static int show_traces_open(struct inode
*inode
, struct file
*file
)
2181 if (tracing_disabled
)
2184 ret
= seq_open(file
, &show_traces_seq_ops
);
2186 struct seq_file
*m
= file
->private_data
;
2187 m
->private = trace_types
;
2193 static struct file_operations tracing_fops
= {
2194 .open
= tracing_open
,
2196 .llseek
= seq_lseek
,
2197 .release
= tracing_release
,
2200 static struct file_operations tracing_lt_fops
= {
2201 .open
= tracing_lt_open
,
2203 .llseek
= seq_lseek
,
2204 .release
= tracing_release
,
2207 static struct file_operations show_traces_fops
= {
2208 .open
= show_traces_open
,
2210 .release
= seq_release
,
2214 * Only trace on a CPU if the bitmask is set:
2216 static cpumask_t tracing_cpumask
= CPU_MASK_ALL
;
2219 * When tracing/tracing_cpu_mask is modified then this holds
2220 * the new bitmask we are about to install:
2222 static cpumask_t tracing_cpumask_new
;
2225 * The tracer itself will not take this lock, but still we want
2226 * to provide a consistent cpumask to user-space:
2228 static DEFINE_MUTEX(tracing_cpumask_update_lock
);
2231 * Temporary storage for the character representation of the
2232 * CPU bitmask (and one more byte for the newline):
2234 static char mask_str
[NR_CPUS
+ 1];
2237 tracing_cpumask_read(struct file
*filp
, char __user
*ubuf
,
2238 size_t count
, loff_t
*ppos
)
2242 mutex_lock(&tracing_cpumask_update_lock
);
2244 len
= cpumask_scnprintf(mask_str
, count
, tracing_cpumask
);
2245 if (count
- len
< 2) {
2249 len
+= sprintf(mask_str
+ len
, "\n");
2250 count
= simple_read_from_buffer(ubuf
, count
, ppos
, mask_str
, NR_CPUS
+1);
2253 mutex_unlock(&tracing_cpumask_update_lock
);
2259 tracing_cpumask_write(struct file
*filp
, const char __user
*ubuf
,
2260 size_t count
, loff_t
*ppos
)
2264 mutex_lock(&tracing_cpumask_update_lock
);
2265 err
= cpumask_parse_user(ubuf
, count
, tracing_cpumask_new
);
2269 raw_local_irq_disable();
2270 __raw_spin_lock(&ftrace_max_lock
);
2271 for_each_tracing_cpu(cpu
) {
2273 * Increase/decrease the disabled counter if we are
2274 * about to flip a bit in the cpumask:
2276 if (cpu_isset(cpu
, tracing_cpumask
) &&
2277 !cpu_isset(cpu
, tracing_cpumask_new
)) {
2278 atomic_inc(&global_trace
.data
[cpu
]->disabled
);
2280 if (!cpu_isset(cpu
, tracing_cpumask
) &&
2281 cpu_isset(cpu
, tracing_cpumask_new
)) {
2282 atomic_dec(&global_trace
.data
[cpu
]->disabled
);
2285 __raw_spin_unlock(&ftrace_max_lock
);
2286 raw_local_irq_enable();
2288 tracing_cpumask
= tracing_cpumask_new
;
2290 mutex_unlock(&tracing_cpumask_update_lock
);
2295 mutex_unlock(&tracing_cpumask_update_lock
);
2300 static struct file_operations tracing_cpumask_fops
= {
2301 .open
= tracing_open_generic
,
2302 .read
= tracing_cpumask_read
,
2303 .write
= tracing_cpumask_write
,
2307 tracing_iter_ctrl_read(struct file
*filp
, char __user
*ubuf
,
2308 size_t cnt
, loff_t
*ppos
)
2315 /* calulate max size */
2316 for (i
= 0; trace_options
[i
]; i
++) {
2317 len
+= strlen(trace_options
[i
]);
2318 len
+= 3; /* "no" and space */
2321 /* +2 for \n and \0 */
2322 buf
= kmalloc(len
+ 2, GFP_KERNEL
);
2326 for (i
= 0; trace_options
[i
]; i
++) {
2327 if (trace_flags
& (1 << i
))
2328 r
+= sprintf(buf
+ r
, "%s ", trace_options
[i
]);
2330 r
+= sprintf(buf
+ r
, "no%s ", trace_options
[i
]);
2333 r
+= sprintf(buf
+ r
, "\n");
2334 WARN_ON(r
>= len
+ 2);
2336 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2344 tracing_iter_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
2345 size_t cnt
, loff_t
*ppos
)
2352 if (cnt
>= sizeof(buf
))
2355 if (copy_from_user(&buf
, ubuf
, cnt
))
2360 if (strncmp(buf
, "no", 2) == 0) {
2365 for (i
= 0; trace_options
[i
]; i
++) {
2366 int len
= strlen(trace_options
[i
]);
2368 if (strncmp(cmp
, trace_options
[i
], len
) == 0) {
2370 trace_flags
&= ~(1 << i
);
2372 trace_flags
|= (1 << i
);
2377 * If no option could be set, return an error:
2379 if (!trace_options
[i
])
2387 static struct file_operations tracing_iter_fops
= {
2388 .open
= tracing_open_generic
,
2389 .read
= tracing_iter_ctrl_read
,
2390 .write
= tracing_iter_ctrl_write
,
2393 static const char readme_msg
[] =
2394 "tracing mini-HOWTO:\n\n"
2396 "# mount -t debugfs nodev /debug\n\n"
2397 "# cat /debug/tracing/available_tracers\n"
2398 "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
2399 "# cat /debug/tracing/current_tracer\n"
2401 "# echo sched_switch > /debug/tracing/current_tracer\n"
2402 "# cat /debug/tracing/current_tracer\n"
2404 "# cat /debug/tracing/iter_ctrl\n"
2405 "noprint-parent nosym-offset nosym-addr noverbose\n"
2406 "# echo print-parent > /debug/tracing/iter_ctrl\n"
2407 "# echo 1 > /debug/tracing/tracing_enabled\n"
2408 "# cat /debug/tracing/trace > /tmp/trace.txt\n"
2409 "echo 0 > /debug/tracing/tracing_enabled\n"
2413 tracing_readme_read(struct file
*filp
, char __user
*ubuf
,
2414 size_t cnt
, loff_t
*ppos
)
2416 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
2417 readme_msg
, strlen(readme_msg
));
2420 static struct file_operations tracing_readme_fops
= {
2421 .open
= tracing_open_generic
,
2422 .read
= tracing_readme_read
,
2426 tracing_ctrl_read(struct file
*filp
, char __user
*ubuf
,
2427 size_t cnt
, loff_t
*ppos
)
2429 struct trace_array
*tr
= filp
->private_data
;
2433 r
= sprintf(buf
, "%ld\n", tr
->ctrl
);
2434 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2438 tracing_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
2439 size_t cnt
, loff_t
*ppos
)
2441 struct trace_array
*tr
= filp
->private_data
;
2446 if (cnt
>= sizeof(buf
))
2449 if (copy_from_user(&buf
, ubuf
, cnt
))
2454 ret
= strict_strtoul(buf
, 10, &val
);
2460 mutex_lock(&trace_types_lock
);
2461 if (tr
->ctrl
^ val
) {
2469 if (current_trace
&& current_trace
->ctrl_update
)
2470 current_trace
->ctrl_update(tr
);
2472 mutex_unlock(&trace_types_lock
);
2480 tracing_set_trace_read(struct file
*filp
, char __user
*ubuf
,
2481 size_t cnt
, loff_t
*ppos
)
2483 char buf
[max_tracer_type_len
+2];
2486 mutex_lock(&trace_types_lock
);
2488 r
= sprintf(buf
, "%s\n", current_trace
->name
);
2490 r
= sprintf(buf
, "\n");
2491 mutex_unlock(&trace_types_lock
);
2493 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2497 tracing_set_trace_write(struct file
*filp
, const char __user
*ubuf
,
2498 size_t cnt
, loff_t
*ppos
)
2500 struct trace_array
*tr
= &global_trace
;
2502 char buf
[max_tracer_type_len
+1];
2505 if (cnt
> max_tracer_type_len
)
2506 cnt
= max_tracer_type_len
;
2508 if (copy_from_user(&buf
, ubuf
, cnt
))
2513 /* strip ending whitespace. */
2514 for (i
= cnt
- 1; i
> 0 && isspace(buf
[i
]); i
--)
2517 mutex_lock(&trace_types_lock
);
2518 for (t
= trace_types
; t
; t
= t
->next
) {
2519 if (strcmp(t
->name
, buf
) == 0)
2522 if (!t
|| t
== current_trace
)
2525 if (current_trace
&& current_trace
->reset
)
2526 current_trace
->reset(tr
);
2533 mutex_unlock(&trace_types_lock
);
2541 tracing_max_lat_read(struct file
*filp
, char __user
*ubuf
,
2542 size_t cnt
, loff_t
*ppos
)
2544 unsigned long *ptr
= filp
->private_data
;
2548 r
= snprintf(buf
, sizeof(buf
), "%ld\n",
2549 *ptr
== (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr
));
2550 if (r
> sizeof(buf
))
2552 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2556 tracing_max_lat_write(struct file
*filp
, const char __user
*ubuf
,
2557 size_t cnt
, loff_t
*ppos
)
2559 long *ptr
= filp
->private_data
;
2564 if (cnt
>= sizeof(buf
))
2567 if (copy_from_user(&buf
, ubuf
, cnt
))
2572 ret
= strict_strtoul(buf
, 10, &val
);
2581 static atomic_t tracing_reader
;
2583 static int tracing_open_pipe(struct inode
*inode
, struct file
*filp
)
2585 struct trace_iterator
*iter
;
2587 if (tracing_disabled
)
2590 /* We only allow for reader of the pipe */
2591 if (atomic_inc_return(&tracing_reader
) != 1) {
2592 atomic_dec(&tracing_reader
);
2596 /* create a buffer to store the information to pass to userspace */
2597 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
2601 mutex_lock(&trace_types_lock
);
2602 iter
->tr
= &global_trace
;
2603 iter
->trace
= current_trace
;
2604 filp
->private_data
= iter
;
2606 if (iter
->trace
->pipe_open
)
2607 iter
->trace
->pipe_open(iter
);
2608 mutex_unlock(&trace_types_lock
);
2613 static int tracing_release_pipe(struct inode
*inode
, struct file
*file
)
2615 struct trace_iterator
*iter
= file
->private_data
;
2618 atomic_dec(&tracing_reader
);
2624 tracing_poll_pipe(struct file
*filp
, poll_table
*poll_table
)
2626 struct trace_iterator
*iter
= filp
->private_data
;
2628 if (trace_flags
& TRACE_ITER_BLOCK
) {
2630 * Always select as readable when in blocking mode
2632 return POLLIN
| POLLRDNORM
;
2634 if (!trace_empty(iter
))
2635 return POLLIN
| POLLRDNORM
;
2636 poll_wait(filp
, &trace_wait
, poll_table
);
2637 if (!trace_empty(iter
))
2638 return POLLIN
| POLLRDNORM
;
2648 tracing_read_pipe(struct file
*filp
, char __user
*ubuf
,
2649 size_t cnt
, loff_t
*ppos
)
2651 struct trace_iterator
*iter
= filp
->private_data
;
2652 struct trace_array_cpu
*data
;
2653 static cpumask_t mask
;
2654 unsigned long flags
;
2655 #ifdef CONFIG_FTRACE
2661 /* return any leftover data */
2662 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
2667 trace_seq_reset(&iter
->seq
);
2669 mutex_lock(&trace_types_lock
);
2670 if (iter
->trace
->read
) {
2671 sret
= iter
->trace
->read(iter
, filp
, ubuf
, cnt
, ppos
);
2676 while (trace_empty(iter
)) {
2678 if ((filp
->f_flags
& O_NONBLOCK
)) {
2684 * This is a make-shift waitqueue. The reason we don't use
2685 * an actual wait queue is because:
2686 * 1) we only ever have one waiter
2687 * 2) the tracing, traces all functions, we don't want
2688 * the overhead of calling wake_up and friends
2689 * (and tracing them too)
2690 * Anyway, this is really very primitive wakeup.
2692 set_current_state(TASK_INTERRUPTIBLE
);
2693 iter
->tr
->waiter
= current
;
2695 mutex_unlock(&trace_types_lock
);
2697 /* sleep for 100 msecs, and try again. */
2698 schedule_timeout(HZ
/10);
2700 mutex_lock(&trace_types_lock
);
2702 iter
->tr
->waiter
= NULL
;
2704 if (signal_pending(current
)) {
2709 if (iter
->trace
!= current_trace
)
2713 * We block until we read something and tracing is disabled.
2714 * We still block if tracing is disabled, but we have never
2715 * read anything. This allows a user to cat this file, and
2716 * then enable tracing. But after we have read something,
2717 * we give an EOF when tracing is again disabled.
2719 * iter->pos will be 0 if we haven't read anything.
2721 if (!tracer_enabled
&& iter
->pos
)
2727 /* stop when tracing is finished */
2728 if (trace_empty(iter
))
2731 if (cnt
>= PAGE_SIZE
)
2732 cnt
= PAGE_SIZE
- 1;
2734 /* reset all but tr, trace, and overruns */
2735 memset(&iter
->seq
, 0,
2736 sizeof(struct trace_iterator
) -
2737 offsetof(struct trace_iterator
, seq
));
2741 * We need to stop all tracing on all CPUS to read the
2742 * the next buffer. This is a bit expensive, but is
2743 * not done often. We fill all what we can read,
2744 * and then release the locks again.
2748 local_irq_save(flags
);
2749 #ifdef CONFIG_FTRACE
2750 ftrace_save
= ftrace_enabled
;
2754 for_each_tracing_cpu(cpu
) {
2755 data
= iter
->tr
->data
[cpu
];
2757 if (!head_page(data
) || !data
->trace_idx
)
2760 atomic_inc(&data
->disabled
);
2764 for_each_cpu_mask(cpu
, mask
) {
2765 data
= iter
->tr
->data
[cpu
];
2766 __raw_spin_lock(&data
->lock
);
2768 if (data
->overrun
> iter
->last_overrun
[cpu
])
2769 iter
->overrun
[cpu
] +=
2770 data
->overrun
- iter
->last_overrun
[cpu
];
2771 iter
->last_overrun
[cpu
] = data
->overrun
;
2774 while (find_next_entry_inc(iter
) != NULL
) {
2776 int len
= iter
->seq
.len
;
2778 ret
= print_trace_line(iter
);
2780 /* don't print partial lines */
2781 iter
->seq
.len
= len
;
2785 trace_consume(iter
);
2787 if (iter
->seq
.len
>= cnt
)
2791 for_each_cpu_mask(cpu
, mask
) {
2792 data
= iter
->tr
->data
[cpu
];
2793 __raw_spin_unlock(&data
->lock
);
2796 for_each_cpu_mask(cpu
, mask
) {
2797 data
= iter
->tr
->data
[cpu
];
2798 atomic_dec(&data
->disabled
);
2800 #ifdef CONFIG_FTRACE
2801 ftrace_enabled
= ftrace_save
;
2803 local_irq_restore(flags
);
2805 /* Now copy what we have to the user */
2806 sret
= trace_seq_to_user(&iter
->seq
, ubuf
, cnt
);
2807 if (iter
->seq
.readpos
>= iter
->seq
.len
)
2808 trace_seq_reset(&iter
->seq
);
2813 mutex_unlock(&trace_types_lock
);
2819 tracing_entries_read(struct file
*filp
, char __user
*ubuf
,
2820 size_t cnt
, loff_t
*ppos
)
2822 struct trace_array
*tr
= filp
->private_data
;
2826 r
= sprintf(buf
, "%lu\n", tr
->entries
);
2827 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2831 tracing_entries_write(struct file
*filp
, const char __user
*ubuf
,
2832 size_t cnt
, loff_t
*ppos
)
2838 if (cnt
>= sizeof(buf
))
2841 if (copy_from_user(&buf
, ubuf
, cnt
))
2846 ret
= strict_strtoul(buf
, 10, &val
);
2850 /* must have at least 1 entry */
2854 mutex_lock(&trace_types_lock
);
2856 if (current_trace
!= &no_tracer
) {
2858 pr_info("ftrace: set current_tracer to none"
2859 " before modifying buffer size\n");
2863 if (val
> global_trace
.entries
) {
2864 long pages_requested
;
2865 unsigned long freeable_pages
;
2867 /* make sure we have enough memory before mapping */
2869 (val
+ (ENTRIES_PER_PAGE
-1)) / ENTRIES_PER_PAGE
;
2871 /* account for each buffer (and max_tr) */
2872 pages_requested
*= tracing_nr_buffers
* 2;
2874 /* Check for overflow */
2875 if (pages_requested
< 0) {
2880 freeable_pages
= determine_dirtyable_memory();
2882 /* we only allow to request 1/4 of useable memory */
2883 if (pages_requested
>
2884 ((freeable_pages
+ tracing_pages_allocated
) / 4)) {
2889 while (global_trace
.entries
< val
) {
2890 if (trace_alloc_page()) {
2894 /* double check that we don't go over the known pages */
2895 if (tracing_pages_allocated
> pages_requested
)
2900 /* include the number of entries in val (inc of page entries) */
2901 while (global_trace
.entries
> val
+ (ENTRIES_PER_PAGE
- 1))
2905 /* check integrity */
2906 for_each_tracing_cpu(i
)
2907 check_pages(global_trace
.data
[i
]);
2911 /* If check pages failed, return ENOMEM */
2912 if (tracing_disabled
)
2915 max_tr
.entries
= global_trace
.entries
;
2916 mutex_unlock(&trace_types_lock
);
2921 static struct file_operations tracing_max_lat_fops
= {
2922 .open
= tracing_open_generic
,
2923 .read
= tracing_max_lat_read
,
2924 .write
= tracing_max_lat_write
,
2927 static struct file_operations tracing_ctrl_fops
= {
2928 .open
= tracing_open_generic
,
2929 .read
= tracing_ctrl_read
,
2930 .write
= tracing_ctrl_write
,
2933 static struct file_operations set_tracer_fops
= {
2934 .open
= tracing_open_generic
,
2935 .read
= tracing_set_trace_read
,
2936 .write
= tracing_set_trace_write
,
2939 static struct file_operations tracing_pipe_fops
= {
2940 .open
= tracing_open_pipe
,
2941 .poll
= tracing_poll_pipe
,
2942 .read
= tracing_read_pipe
,
2943 .release
= tracing_release_pipe
,
2946 static struct file_operations tracing_entries_fops
= {
2947 .open
= tracing_open_generic
,
2948 .read
= tracing_entries_read
,
2949 .write
= tracing_entries_write
,
2952 #ifdef CONFIG_DYNAMIC_FTRACE
2955 tracing_read_long(struct file
*filp
, char __user
*ubuf
,
2956 size_t cnt
, loff_t
*ppos
)
2958 unsigned long *p
= filp
->private_data
;
2962 r
= sprintf(buf
, "%ld\n", *p
);
2964 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
2967 static struct file_operations tracing_read_long_fops
= {
2968 .open
= tracing_open_generic
,
2969 .read
= tracing_read_long
,
2973 static struct dentry
*d_tracer
;
2975 struct dentry
*tracing_init_dentry(void)
2982 d_tracer
= debugfs_create_dir("tracing", NULL
);
2984 if (!d_tracer
&& !once
) {
2986 pr_warning("Could not create debugfs directory 'tracing'\n");
2993 #ifdef CONFIG_FTRACE_SELFTEST
2994 /* Let selftest have access to static functions in this file */
2995 #include "trace_selftest.c"
2998 static __init
void tracer_init_debugfs(void)
3000 struct dentry
*d_tracer
;
3001 struct dentry
*entry
;
3003 d_tracer
= tracing_init_dentry();
3005 entry
= debugfs_create_file("tracing_enabled", 0644, d_tracer
,
3006 &global_trace
, &tracing_ctrl_fops
);
3008 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
3010 entry
= debugfs_create_file("iter_ctrl", 0644, d_tracer
,
3011 NULL
, &tracing_iter_fops
);
3013 pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
3015 entry
= debugfs_create_file("tracing_cpumask", 0644, d_tracer
,
3016 NULL
, &tracing_cpumask_fops
);
3018 pr_warning("Could not create debugfs 'tracing_cpumask' entry\n");
3020 entry
= debugfs_create_file("latency_trace", 0444, d_tracer
,
3021 &global_trace
, &tracing_lt_fops
);
3023 pr_warning("Could not create debugfs 'latency_trace' entry\n");
3025 entry
= debugfs_create_file("trace", 0444, d_tracer
,
3026 &global_trace
, &tracing_fops
);
3028 pr_warning("Could not create debugfs 'trace' entry\n");
3030 entry
= debugfs_create_file("available_tracers", 0444, d_tracer
,
3031 &global_trace
, &show_traces_fops
);
3033 pr_warning("Could not create debugfs 'available_tracers' entry\n");
3035 entry
= debugfs_create_file("current_tracer", 0444, d_tracer
,
3036 &global_trace
, &set_tracer_fops
);
3038 pr_warning("Could not create debugfs 'current_tracer' entry\n");
3040 entry
= debugfs_create_file("tracing_max_latency", 0644, d_tracer
,
3041 &tracing_max_latency
,
3042 &tracing_max_lat_fops
);
3044 pr_warning("Could not create debugfs "
3045 "'tracing_max_latency' entry\n");
3047 entry
= debugfs_create_file("tracing_thresh", 0644, d_tracer
,
3048 &tracing_thresh
, &tracing_max_lat_fops
);
3050 pr_warning("Could not create debugfs "
3051 "'tracing_thresh' entry\n");
3052 entry
= debugfs_create_file("README", 0644, d_tracer
,
3053 NULL
, &tracing_readme_fops
);
3055 pr_warning("Could not create debugfs 'README' entry\n");
3057 entry
= debugfs_create_file("trace_pipe", 0644, d_tracer
,
3058 NULL
, &tracing_pipe_fops
);
3060 pr_warning("Could not create debugfs "
3061 "'trace_pipe' entry\n");
3063 entry
= debugfs_create_file("trace_entries", 0644, d_tracer
,
3064 &global_trace
, &tracing_entries_fops
);
3066 pr_warning("Could not create debugfs "
3067 "'trace_entries' entry\n");
3069 #ifdef CONFIG_DYNAMIC_FTRACE
3070 entry
= debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer
,
3071 &ftrace_update_tot_cnt
,
3072 &tracing_read_long_fops
);
3074 pr_warning("Could not create debugfs "
3075 "'dyn_ftrace_total_info' entry\n");
3077 #ifdef CONFIG_SYSPROF_TRACER
3078 init_tracer_sysprof_debugfs(d_tracer
);
3082 #define TRACE_BUF_SIZE 1024
3083 #define TRACE_PRINT_BUF_SIZE \
3084 (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf))
3085 #define TRACE_CONT_BUF_SIZE sizeof(struct trace_field)
3087 int __ftrace_printk(unsigned long ip
, const char *fmt
, ...)
3089 struct trace_array
*tr
= &global_trace
;
3090 static DEFINE_SPINLOCK(trace_buf_lock
);
3091 static char trace_buf
[TRACE_BUF_SIZE
];
3092 struct trace_array_cpu
*data
;
3093 struct trace_entry
*entry
;
3094 unsigned long flags
;
3097 int cpu
, len
= 0, write
, written
= 0;
3099 if (likely(!ftrace_function_enabled
))
3102 local_irq_save(flags
);
3103 cpu
= raw_smp_processor_id();
3104 data
= tr
->data
[cpu
];
3105 disabled
= atomic_inc_return(&data
->disabled
);
3107 if (unlikely(disabled
!= 1 || !ftrace_function_enabled
))
3110 spin_lock(&trace_buf_lock
);
3112 len
= vsnprintf(trace_buf
, TRACE_BUF_SIZE
, fmt
, ap
);
3115 len
= min(len
, TRACE_BUF_SIZE
-1);
3118 __raw_spin_lock(&data
->lock
);
3119 entry
= tracing_get_trace_entry(tr
, data
);
3120 tracing_generic_entry_update(entry
, flags
);
3121 entry
->type
= TRACE_PRINT
;
3122 entry
->field
.print
.ip
= ip
;
3124 write
= min(len
, (int)(TRACE_PRINT_BUF_SIZE
-1));
3126 memcpy(&entry
->field
.print
.buf
, trace_buf
, write
);
3127 entry
->field
.print
.buf
[write
] = 0;
3131 entry
->field
.flags
|= TRACE_FLAG_CONT
;
3133 while (written
!= len
) {
3134 entry
= tracing_get_trace_entry(tr
, data
);
3136 entry
->type
= TRACE_CONT
;
3137 write
= min(len
- written
, (int)(TRACE_CONT_BUF_SIZE
-1));
3138 memcpy(&entry
->cont
.buf
, trace_buf
+written
, write
);
3139 entry
->cont
.buf
[write
] = 0;
3142 __raw_spin_unlock(&data
->lock
);
3144 spin_unlock(&trace_buf_lock
);
3147 atomic_dec(&data
->disabled
);
3148 local_irq_restore(flags
);
3152 EXPORT_SYMBOL_GPL(__ftrace_printk
);
3154 static int trace_panic_handler(struct notifier_block
*this,
3155 unsigned long event
, void *unused
)
3161 static struct notifier_block trace_panic_notifier
= {
3162 .notifier_call
= trace_panic_handler
,
3164 .priority
= 150 /* priority: INT_MAX >= x >= 0 */
3167 static int trace_die_handler(struct notifier_block
*self
,
3181 static struct notifier_block trace_die_notifier
= {
3182 .notifier_call
= trace_die_handler
,
3187 * printk is set to max of 1024, we really don't need it that big.
3188 * Nothing should be printing 1000 characters anyway.
3190 #define TRACE_MAX_PRINT 1000
3193 * Define here KERN_TRACE so that we have one place to modify
3194 * it if we decide to change what log level the ftrace dump
3197 #define KERN_TRACE KERN_INFO
3200 trace_printk_seq(struct trace_seq
*s
)
3202 /* Probably should print a warning here. */
3206 /* should be zero ended, but we are paranoid. */
3207 s
->buffer
[s
->len
] = 0;
3209 printk(KERN_TRACE
"%s", s
->buffer
);
3215 void ftrace_dump(void)
3217 static DEFINE_SPINLOCK(ftrace_dump_lock
);
3218 /* use static because iter can be a bit big for the stack */
3219 static struct trace_iterator iter
;
3220 struct trace_array_cpu
*data
;
3221 static cpumask_t mask
;
3222 static int dump_ran
;
3223 unsigned long flags
;
3228 spin_lock_irqsave(&ftrace_dump_lock
, flags
);
3234 /* No turning back! */
3235 ftrace_kill_atomic();
3237 printk(KERN_TRACE
"Dumping ftrace buffer:\n");
3239 iter
.tr
= &global_trace
;
3240 iter
.trace
= current_trace
;
3243 * We need to stop all tracing on all CPUS to read the
3244 * the next buffer. This is a bit expensive, but is
3245 * not done often. We fill all what we can read,
3246 * and then release the locks again.
3251 for_each_tracing_cpu(cpu
) {
3252 data
= iter
.tr
->data
[cpu
];
3254 if (!head_page(data
) || !data
->trace_idx
)
3257 atomic_inc(&data
->disabled
);
3261 for_each_cpu_mask(cpu
, mask
) {
3262 data
= iter
.tr
->data
[cpu
];
3263 __raw_spin_lock(&data
->lock
);
3265 if (data
->overrun
> iter
.last_overrun
[cpu
])
3266 iter
.overrun
[cpu
] +=
3267 data
->overrun
- iter
.last_overrun
[cpu
];
3268 iter
.last_overrun
[cpu
] = data
->overrun
;
3271 while (!trace_empty(&iter
)) {
3274 printk(KERN_TRACE
"---------------------------------\n");
3278 /* reset all but tr, trace, and overruns */
3279 memset(&iter
.seq
, 0,
3280 sizeof(struct trace_iterator
) -
3281 offsetof(struct trace_iterator
, seq
));
3282 iter
.iter_flags
|= TRACE_FILE_LAT_FMT
;
3285 if (find_next_entry_inc(&iter
) != NULL
) {
3286 print_trace_line(&iter
);
3287 trace_consume(&iter
);
3290 trace_printk_seq(&iter
.seq
);
3294 printk(KERN_TRACE
" (ftrace buffer empty)\n");
3296 printk(KERN_TRACE
"---------------------------------\n");
3298 for_each_cpu_mask(cpu
, mask
) {
3299 data
= iter
.tr
->data
[cpu
];
3300 __raw_spin_unlock(&data
->lock
);
3303 for_each_cpu_mask(cpu
, mask
) {
3304 data
= iter
.tr
->data
[cpu
];
3305 atomic_dec(&data
->disabled
);
3310 spin_unlock_irqrestore(&ftrace_dump_lock
, flags
);
3313 static int trace_alloc_page(void)
3315 struct trace_array_cpu
*data
;
3316 struct page
*page
, *tmp
;
3319 unsigned pages_allocated
= 0;
3322 /* first allocate a page for each CPU */
3323 for_each_tracing_cpu(i
) {
3324 array
= (void *)__get_free_page(GFP_KERNEL
);
3325 if (array
== NULL
) {
3326 printk(KERN_ERR
"tracer: failed to allocate page"
3327 "for trace buffer!\n");
3332 page
= virt_to_page(array
);
3333 list_add(&page
->lru
, &pages
);
3335 /* Only allocate if we are actually using the max trace */
3336 #ifdef CONFIG_TRACER_MAX_TRACE
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");
3344 page
= virt_to_page(array
);
3345 list_add(&page
->lru
, &pages
);
3349 /* Now that we successfully allocate a page per CPU, add them */
3350 for_each_tracing_cpu(i
) {
3351 data
= global_trace
.data
[i
];
3352 page
= list_entry(pages
.next
, struct page
, lru
);
3353 list_del_init(&page
->lru
);
3354 list_add_tail(&page
->lru
, &data
->trace_pages
);
3357 #ifdef CONFIG_TRACER_MAX_TRACE
3358 data
= max_tr
.data
[i
];
3359 page
= list_entry(pages
.next
, struct page
, lru
);
3360 list_del_init(&page
->lru
);
3361 list_add_tail(&page
->lru
, &data
->trace_pages
);
3365 tracing_pages_allocated
+= pages_allocated
;
3366 global_trace
.entries
+= ENTRIES_PER_PAGE
;
3371 list_for_each_entry_safe(page
, tmp
, &pages
, lru
) {
3372 list_del_init(&page
->lru
);
3378 static int trace_free_page(void)
3380 struct trace_array_cpu
*data
;
3382 struct list_head
*p
;
3386 /* free one page from each buffer */
3387 for_each_tracing_cpu(i
) {
3388 data
= global_trace
.data
[i
];
3389 p
= data
->trace_pages
.next
;
3390 if (p
== &data
->trace_pages
) {
3391 /* should never happen */
3393 tracing_disabled
= 1;
3397 page
= list_entry(p
, struct page
, lru
);
3399 list_del(&page
->lru
);
3400 tracing_pages_allocated
--;
3401 tracing_pages_allocated
--;
3404 tracing_reset(data
);
3406 #ifdef CONFIG_TRACER_MAX_TRACE
3407 data
= max_tr
.data
[i
];
3408 p
= data
->trace_pages
.next
;
3409 if (p
== &data
->trace_pages
) {
3410 /* should never happen */
3412 tracing_disabled
= 1;
3416 page
= list_entry(p
, struct page
, lru
);
3418 list_del(&page
->lru
);
3421 tracing_reset(data
);
3424 global_trace
.entries
-= ENTRIES_PER_PAGE
;
3429 __init
static int tracer_alloc_buffers(void)
3431 struct trace_array_cpu
*data
;
3438 /* TODO: make the number of buffers hot pluggable with CPUS */
3439 tracing_nr_buffers
= num_possible_cpus();
3440 tracing_buffer_mask
= cpu_possible_map
;
3442 /* Allocate the first page for all buffers */
3443 for_each_tracing_cpu(i
) {
3444 data
= global_trace
.data
[i
] = &per_cpu(global_trace_cpu
, i
);
3445 max_tr
.data
[i
] = &per_cpu(max_data
, i
);
3447 array
= (void *)__get_free_page(GFP_KERNEL
);
3448 if (array
== NULL
) {
3449 printk(KERN_ERR
"tracer: failed to allocate page"
3450 "for trace buffer!\n");
3454 /* set the array to the list */
3455 INIT_LIST_HEAD(&data
->trace_pages
);
3456 page
= virt_to_page(array
);
3457 list_add(&page
->lru
, &data
->trace_pages
);
3458 /* use the LRU flag to differentiate the two buffers */
3461 data
->lock
= (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
3462 max_tr
.data
[i
]->lock
= (raw_spinlock_t
)__RAW_SPIN_LOCK_UNLOCKED
;
3464 /* Only allocate if we are actually using the max trace */
3465 #ifdef CONFIG_TRACER_MAX_TRACE
3466 array
= (void *)__get_free_page(GFP_KERNEL
);
3467 if (array
== NULL
) {
3468 printk(KERN_ERR
"tracer: failed to allocate page"
3469 "for trace buffer!\n");
3473 INIT_LIST_HEAD(&max_tr
.data
[i
]->trace_pages
);
3474 page
= virt_to_page(array
);
3475 list_add(&page
->lru
, &max_tr
.data
[i
]->trace_pages
);
3481 * Since we allocate by orders of pages, we may be able to
3484 global_trace
.entries
= ENTRIES_PER_PAGE
;
3487 while (global_trace
.entries
< trace_nr_entries
) {
3488 if (trace_alloc_page())
3492 max_tr
.entries
= global_trace
.entries
;
3494 pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n",
3495 pages
, trace_nr_entries
, (long)TRACE_ENTRY_SIZE
);
3496 pr_info(" actual entries %ld\n", global_trace
.entries
);
3498 tracer_init_debugfs();
3500 trace_init_cmdlines();
3502 register_tracer(&no_tracer
);
3503 current_trace
= &no_tracer
;
3505 /* All seems OK, enable tracing */
3506 global_trace
.ctrl
= tracer_enabled
;
3507 tracing_disabled
= 0;
3509 atomic_notifier_chain_register(&panic_notifier_list
,
3510 &trace_panic_notifier
);
3512 register_die_notifier(&trace_die_notifier
);
3517 for (i
-- ; i
>= 0; i
--) {
3518 struct page
*page
, *tmp
;
3519 struct trace_array_cpu
*data
= global_trace
.data
[i
];
3522 list_for_each_entry_safe(page
, tmp
,
3523 &data
->trace_pages
, lru
) {
3524 list_del_init(&page
->lru
);
3529 #ifdef CONFIG_TRACER_MAX_TRACE
3530 data
= max_tr
.data
[i
];
3532 list_for_each_entry_safe(page
, tmp
,
3533 &data
->trace_pages
, lru
) {
3534 list_del_init(&page
->lru
);
3542 fs_initcall(tracer_alloc_buffers
);