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/debugfs.h>
18 #include <linux/pagemap.h>
19 #include <linux/hardirq.h>
20 #include <linux/linkage.h>
21 #include <linux/uaccess.h>
22 #include <linux/ftrace.h>
23 #include <linux/module.h>
24 #include <linux/percpu.h>
25 #include <linux/ctype.h>
26 #include <linux/init.h>
27 #include <linux/gfp.h>
32 unsigned long __read_mostly tracing_max_latency
= (cycle_t
)ULONG_MAX
;
33 unsigned long __read_mostly tracing_thresh
;
35 static int tracing_disabled
= 1;
38 ns2usecs(cycle_t nsec
)
45 static atomic_t tracer_counter
;
46 static struct trace_array global_trace
;
48 static DEFINE_PER_CPU(struct trace_array_cpu
, global_trace_cpu
);
50 static struct trace_array max_tr
;
52 static DEFINE_PER_CPU(struct trace_array_cpu
, max_data
);
54 static int tracer_enabled
;
55 static unsigned long trace_nr_entries
= 16384UL;
57 static struct tracer
*trace_types __read_mostly
;
58 static struct tracer
*current_trace __read_mostly
;
59 static int max_tracer_type_len
;
61 static DEFINE_MUTEX(trace_types_lock
);
63 #define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry))
65 static int __init
set_nr_entries(char *str
)
69 trace_nr_entries
= simple_strtoul(str
, &str
, 0);
72 __setup("trace_entries=", set_nr_entries
);
74 unsigned long nsecs_to_usecs(unsigned long nsecs
)
80 __TRACE_FIRST_TYPE
= 0,
88 enum trace_flag_type
{
89 TRACE_FLAG_IRQS_OFF
= 0x01,
90 TRACE_FLAG_NEED_RESCHED
= 0x02,
91 TRACE_FLAG_HARDIRQ
= 0x04,
92 TRACE_FLAG_SOFTIRQ
= 0x08,
95 enum trace_iterator_flags
{
96 TRACE_ITER_PRINT_PARENT
= 0x01,
97 TRACE_ITER_SYM_OFFSET
= 0x02,
98 TRACE_ITER_SYM_ADDR
= 0x04,
99 TRACE_ITER_VERBOSE
= 0x08,
102 #define TRACE_ITER_SYM_MASK \
103 (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
105 /* These must match the bit postions above */
106 static const char *trace_options
[] = {
114 static unsigned trace_flags
;
116 static DEFINE_SPINLOCK(ftrace_max_lock
);
119 * Copy the new maximum trace into the separate maximum-trace
120 * structure. (this way the maximum trace is permanently saved,
121 * for later retrieval via /debugfs/tracing/latency_trace)
124 __update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
126 struct trace_array_cpu
*data
= tr
->data
[cpu
];
129 max_tr
.time_start
= data
->preempt_timestamp
;
131 data
= max_tr
.data
[cpu
];
132 data
->saved_latency
= tracing_max_latency
;
134 memcpy(data
->comm
, tsk
->comm
, TASK_COMM_LEN
);
135 data
->pid
= tsk
->pid
;
136 data
->uid
= tsk
->uid
;
137 data
->nice
= tsk
->static_prio
- 20 - MAX_RT_PRIO
;
138 data
->policy
= tsk
->policy
;
139 data
->rt_priority
= tsk
->rt_priority
;
141 /* record this tasks comm */
142 tracing_record_cmdline(current
);
145 void check_pages(struct trace_array_cpu
*data
)
147 struct page
*page
, *tmp
;
149 BUG_ON(data
->trace_pages
.next
->prev
!= &data
->trace_pages
);
150 BUG_ON(data
->trace_pages
.prev
->next
!= &data
->trace_pages
);
152 list_for_each_entry_safe(page
, tmp
, &data
->trace_pages
, lru
) {
153 BUG_ON(page
->lru
.next
->prev
!= &page
->lru
);
154 BUG_ON(page
->lru
.prev
->next
!= &page
->lru
);
158 void *head_page(struct trace_array_cpu
*data
)
163 if (list_empty(&data
->trace_pages
))
166 page
= list_entry(data
->trace_pages
.next
, struct page
, lru
);
167 BUG_ON(&page
->lru
== &data
->trace_pages
);
169 return page_address(page
);
173 flip_trace(struct trace_array_cpu
*tr1
, struct trace_array_cpu
*tr2
)
175 struct list_head flip_pages
;
177 INIT_LIST_HEAD(&flip_pages
);
179 tr1
->trace_current
= NULL
;
180 memcpy(&tr1
->trace_current_idx
, &tr2
->trace_current_idx
,
181 sizeof(struct trace_array_cpu
) -
182 offsetof(struct trace_array_cpu
, trace_current_idx
));
186 list_splice_init(&tr1
->trace_pages
, &flip_pages
);
187 list_splice_init(&tr2
->trace_pages
, &tr1
->trace_pages
);
188 list_splice_init(&flip_pages
, &tr2
->trace_pages
);
189 BUG_ON(!list_empty(&flip_pages
));
195 update_max_tr(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
197 struct trace_array_cpu
*data
;
200 WARN_ON_ONCE(!irqs_disabled());
201 spin_lock(&ftrace_max_lock
);
202 /* clear out all the previous traces */
203 for_each_possible_cpu(i
) {
205 flip_trace(max_tr
.data
[i
], data
);
209 __update_max_tr(tr
, tsk
, cpu
);
210 spin_unlock(&ftrace_max_lock
);
214 * update_max_tr_single - only copy one trace over, and reset the rest
216 * @tsk - task with the latency
217 * @cpu - the cpu of the buffer to copy.
220 update_max_tr_single(struct trace_array
*tr
, struct task_struct
*tsk
, int cpu
)
222 struct trace_array_cpu
*data
= tr
->data
[cpu
];
225 WARN_ON_ONCE(!irqs_disabled());
226 spin_lock(&ftrace_max_lock
);
227 for_each_possible_cpu(i
)
228 tracing_reset(max_tr
.data
[i
]);
230 flip_trace(max_tr
.data
[cpu
], data
);
234 __update_max_tr(tr
, tsk
, cpu
);
235 spin_unlock(&ftrace_max_lock
);
238 int register_tracer(struct tracer
*type
)
245 pr_info("Tracer must have a name\n");
249 mutex_lock(&trace_types_lock
);
250 for (t
= trace_types
; t
; t
= t
->next
) {
251 if (strcmp(type
->name
, t
->name
) == 0) {
253 pr_info("Trace %s already registered\n",
260 #ifdef CONFIG_FTRACE_STARTUP_TEST
261 if (type
->selftest
) {
262 struct tracer
*saved_tracer
= current_trace
;
263 struct trace_array_cpu
*data
;
264 struct trace_array
*tr
= &global_trace
;
265 int saved_ctrl
= tr
->ctrl
;
268 * Run a selftest on this tracer.
269 * Here we reset the trace buffer, and set the current
270 * tracer to be this tracer. The tracer can then run some
271 * internal tracing to verify that everything is in order.
272 * If we fail, we do not register this tracer.
274 for_each_possible_cpu(i
) {
276 if (!head_page(data
))
280 current_trace
= type
;
282 /* the test is responsible for initializing and enabling */
283 pr_info("Testing tracer %s: ", type
->name
);
284 ret
= type
->selftest(type
, tr
);
285 /* the test is responsible for resetting too */
286 current_trace
= saved_tracer
;
287 tr
->ctrl
= saved_ctrl
;
289 printk(KERN_CONT
"FAILED!\n");
292 /* Only reset on passing, to avoid touching corrupted buffers */
293 for_each_possible_cpu(i
) {
295 if (!head_page(data
))
299 printk(KERN_CONT
"PASSED\n");
303 type
->next
= trace_types
;
305 len
= strlen(type
->name
);
306 if (len
> max_tracer_type_len
)
307 max_tracer_type_len
= len
;
310 mutex_unlock(&trace_types_lock
);
315 void unregister_tracer(struct tracer
*type
)
320 mutex_lock(&trace_types_lock
);
321 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
325 pr_info("Trace %s not registered\n", type
->name
);
330 if (strlen(type
->name
) != max_tracer_type_len
)
333 max_tracer_type_len
= 0;
334 for (t
= &trace_types
; *t
; t
= &(*t
)->next
) {
335 len
= strlen((*t
)->name
);
336 if (len
> max_tracer_type_len
)
337 max_tracer_type_len
= len
;
340 mutex_unlock(&trace_types_lock
);
343 notrace
void tracing_reset(struct trace_array_cpu
*data
)
346 data
->trace_current
= head_page(data
);
347 data
->trace_current_idx
= 0;
348 data
->time_offset
= 0;
353 function_trace_call(unsigned long ip
, unsigned long parent_ip
)
355 struct trace_array
*tr
= &global_trace
;
356 struct trace_array_cpu
*data
;
361 if (unlikely(!tracer_enabled
))
364 local_irq_save(flags
);
365 cpu
= raw_smp_processor_id();
366 data
= tr
->data
[cpu
];
367 disabled
= atomic_inc_return(&data
->disabled
);
369 if (likely(disabled
== 1))
370 ftrace(tr
, data
, ip
, parent_ip
, flags
);
372 atomic_dec(&data
->disabled
);
373 local_irq_restore(flags
);
376 static struct ftrace_ops trace_ops __read_mostly
=
378 .func
= function_trace_call
,
382 notrace
void tracing_start_function_trace(void)
384 register_ftrace_function(&trace_ops
);
387 notrace
void tracing_stop_function_trace(void)
389 unregister_ftrace_function(&trace_ops
);
392 #define SAVED_CMDLINES 128
393 static unsigned map_pid_to_cmdline
[PID_MAX_DEFAULT
+1];
394 static unsigned map_cmdline_to_pid
[SAVED_CMDLINES
];
395 static char saved_cmdlines
[SAVED_CMDLINES
][TASK_COMM_LEN
];
396 static int cmdline_idx
;
397 static DEFINE_SPINLOCK(trace_cmdline_lock
);
398 atomic_t trace_record_cmdline_disabled
;
400 static void trace_init_cmdlines(void)
402 memset(&map_pid_to_cmdline
, -1, sizeof(map_pid_to_cmdline
));
403 memset(&map_cmdline_to_pid
, -1, sizeof(map_cmdline_to_pid
));
407 notrace
void trace_stop_cmdline_recording(void);
409 static notrace
void trace_save_cmdline(struct task_struct
*tsk
)
414 if (!tsk
->pid
|| unlikely(tsk
->pid
> PID_MAX_DEFAULT
))
418 * It's not the end of the world if we don't get
419 * the lock, but we also don't want to spin
420 * nor do we want to disable interrupts,
421 * so if we miss here, then better luck next time.
423 if (!spin_trylock(&trace_cmdline_lock
))
426 idx
= map_pid_to_cmdline
[tsk
->pid
];
427 if (idx
>= SAVED_CMDLINES
) {
428 idx
= (cmdline_idx
+ 1) % SAVED_CMDLINES
;
430 map
= map_cmdline_to_pid
[idx
];
431 if (map
<= PID_MAX_DEFAULT
)
432 map_pid_to_cmdline
[map
] = (unsigned)-1;
434 map_pid_to_cmdline
[tsk
->pid
] = idx
;
439 memcpy(&saved_cmdlines
[idx
], tsk
->comm
, TASK_COMM_LEN
);
441 spin_unlock(&trace_cmdline_lock
);
444 static notrace
char *trace_find_cmdline(int pid
)
446 char *cmdline
= "<...>";
452 if (pid
> PID_MAX_DEFAULT
)
455 map
= map_pid_to_cmdline
[pid
];
456 if (map
>= SAVED_CMDLINES
)
459 cmdline
= saved_cmdlines
[map
];
465 notrace
void tracing_record_cmdline(struct task_struct
*tsk
)
467 if (atomic_read(&trace_record_cmdline_disabled
))
470 trace_save_cmdline(tsk
);
473 static inline notrace
struct trace_entry
*
474 tracing_get_trace_entry(struct trace_array
*tr
, struct trace_array_cpu
*data
)
476 unsigned long idx
, idx_next
;
477 struct trace_entry
*entry
;
478 struct list_head
*next
;
482 idx
= data
->trace_current_idx
;
485 BUG_ON(idx
* TRACE_ENTRY_SIZE
>= PAGE_SIZE
);
487 entry
= data
->trace_current
+ idx
* TRACE_ENTRY_SIZE
;
489 if (unlikely(idx_next
>= ENTRIES_PER_PAGE
)) {
490 page
= virt_to_page(data
->trace_current
);
492 * Roundrobin - but skip the head (which is not a real page):
494 next
= page
->lru
.next
;
495 if (unlikely(next
== &data
->trace_pages
))
497 BUG_ON(next
== &data
->trace_pages
);
499 page
= list_entry(next
, struct page
, lru
);
500 data
->trace_current
= page_address(page
);
504 data
->trace_current_idx
= idx_next
;
509 static inline notrace
void
510 tracing_generic_entry_update(struct trace_entry
*entry
, unsigned long flags
)
512 struct task_struct
*tsk
= current
;
515 pc
= preempt_count();
517 entry
->idx
= atomic_inc_return(&tracer_counter
);
518 entry
->preempt_count
= pc
& 0xff;
519 entry
->pid
= tsk
->pid
;
520 entry
->t
= now(raw_smp_processor_id());
521 entry
->flags
= (irqs_disabled_flags(flags
) ? TRACE_FLAG_IRQS_OFF
: 0) |
522 ((pc
& HARDIRQ_MASK
) ? TRACE_FLAG_HARDIRQ
: 0) |
523 ((pc
& SOFTIRQ_MASK
) ? TRACE_FLAG_SOFTIRQ
: 0) |
524 (need_resched() ? TRACE_FLAG_NEED_RESCHED
: 0);
528 ftrace(struct trace_array
*tr
, struct trace_array_cpu
*data
,
529 unsigned long ip
, unsigned long parent_ip
, unsigned long flags
)
531 struct trace_entry
*entry
;
533 entry
= tracing_get_trace_entry(tr
, data
);
534 tracing_generic_entry_update(entry
, flags
);
535 entry
->type
= TRACE_FN
;
537 entry
->fn
.parent_ip
= parent_ip
;
541 tracing_sched_switch_trace(struct trace_array
*tr
,
542 struct trace_array_cpu
*data
,
543 struct task_struct
*prev
, struct task_struct
*next
,
546 struct trace_entry
*entry
;
548 entry
= tracing_get_trace_entry(tr
, data
);
549 tracing_generic_entry_update(entry
, flags
);
550 entry
->type
= TRACE_CTX
;
551 entry
->ctx
.prev_pid
= prev
->pid
;
552 entry
->ctx
.prev_prio
= prev
->prio
;
553 entry
->ctx
.prev_state
= prev
->state
;
554 entry
->ctx
.next_pid
= next
->pid
;
555 entry
->ctx
.next_prio
= next
->prio
;
558 enum trace_file_type
{
559 TRACE_FILE_LAT_FMT
= 1,
562 static struct trace_entry
*
563 trace_entry_idx(struct trace_array
*tr
, struct trace_array_cpu
*data
,
564 struct trace_iterator
*iter
, int cpu
)
567 struct trace_entry
*array
;
569 if (iter
->next_idx
[cpu
] >= tr
->entries
||
570 iter
->next_idx
[cpu
] >= data
->trace_idx
)
573 if (!iter
->next_page
[cpu
]) {
575 * Initialize. If the count of elements in
576 * this buffer is greater than the max entries
577 * we had an underrun. Which means we looped around.
578 * We can simply use the current pointer as our
581 if (data
->trace_idx
>= tr
->entries
) {
582 page
= virt_to_page(data
->trace_current
);
583 iter
->next_page
[cpu
] = &page
->lru
;
584 iter
->next_page_idx
[cpu
] = data
->trace_current_idx
;
586 iter
->next_page
[cpu
] = data
->trace_pages
.next
;
587 iter
->next_page_idx
[cpu
] = 0;
591 page
= list_entry(iter
->next_page
[cpu
], struct page
, lru
);
592 BUG_ON(&data
->trace_pages
== &page
->lru
);
594 array
= page_address(page
);
596 return &array
[iter
->next_page_idx
[cpu
]];
599 static struct notrace trace_entry
*
600 find_next_entry(struct trace_iterator
*iter
, int *ent_cpu
)
602 struct trace_array
*tr
= iter
->tr
;
603 struct trace_entry
*ent
, *next
= NULL
;
607 for_each_possible_cpu(cpu
) {
608 if (!head_page(tr
->data
[cpu
]))
610 ent
= trace_entry_idx(tr
, tr
->data
[cpu
], iter
, cpu
);
612 (!next
|| (long)(next
->idx
- ent
->idx
) > 0)) {
624 static void *find_next_entry_inc(struct trace_iterator
*iter
)
626 struct trace_entry
*next
;
629 next
= find_next_entry(iter
, &next_cpu
);
633 iter
->next_idx
[next_cpu
]++;
634 iter
->next_page_idx
[next_cpu
]++;
636 if (iter
->next_page_idx
[next_cpu
] >= ENTRIES_PER_PAGE
) {
637 struct trace_array_cpu
*data
= iter
->tr
->data
[next_cpu
];
639 iter
->next_page_idx
[next_cpu
] = 0;
640 iter
->next_page
[next_cpu
] =
641 iter
->next_page
[next_cpu
]->next
;
642 if (iter
->next_page
[next_cpu
] == &data
->trace_pages
)
643 iter
->next_page
[next_cpu
] =
644 data
->trace_pages
.next
;
647 iter
->prev_ent
= iter
->ent
;
648 iter
->prev_cpu
= iter
->cpu
;
651 iter
->cpu
= next_cpu
;
653 return next
? iter
: NULL
;
656 static notrace
void *s_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
658 struct trace_iterator
*iter
= m
->private;
659 void *last_ent
= iter
->ent
;
665 /* can't go backwards */
670 ent
= find_next_entry_inc(iter
);
674 while (ent
&& iter
->idx
< i
)
675 ent
= find_next_entry_inc(iter
);
679 if (last_ent
&& !ent
)
680 seq_puts(m
, "\n\nvim:ft=help\n");
685 static void *s_start(struct seq_file
*m
, loff_t
*pos
)
687 struct trace_iterator
*iter
= m
->private;
692 mutex_lock(&trace_types_lock
);
694 if (!current_trace
|| current_trace
!= iter
->trace
)
697 atomic_inc(&trace_record_cmdline_disabled
);
699 /* let the tracer grab locks here if needed */
700 if (current_trace
->start
)
701 current_trace
->start(iter
);
703 if (*pos
!= iter
->pos
) {
707 iter
->prev_ent
= NULL
;
710 for_each_possible_cpu(i
) {
711 iter
->next_idx
[i
] = 0;
712 iter
->next_page
[i
] = NULL
;
715 for (p
= iter
; p
&& l
< *pos
; p
= s_next(m
, p
, &l
))
720 p
= s_next(m
, p
, &l
);
726 static void s_stop(struct seq_file
*m
, void *p
)
728 struct trace_iterator
*iter
= m
->private;
730 atomic_dec(&trace_record_cmdline_disabled
);
732 /* let the tracer release locks here if needed */
733 if (current_trace
&& current_trace
== iter
->trace
&& iter
->trace
->stop
)
734 iter
->trace
->stop(iter
);
736 mutex_unlock(&trace_types_lock
);
740 seq_print_sym_short(struct seq_file
*m
, const char *fmt
, unsigned long address
)
742 #ifdef CONFIG_KALLSYMS
743 char str
[KSYM_SYMBOL_LEN
];
745 kallsyms_lookup(address
, NULL
, NULL
, NULL
, str
);
747 seq_printf(m
, fmt
, str
);
752 seq_print_sym_offset(struct seq_file
*m
, const char *fmt
, unsigned long address
)
754 #ifdef CONFIG_KALLSYMS
755 char str
[KSYM_SYMBOL_LEN
];
757 sprint_symbol(str
, address
);
758 seq_printf(m
, fmt
, str
);
763 # define IP_FMT "%08lx"
765 # define IP_FMT "%016lx"
769 seq_print_ip_sym(struct seq_file
*m
, unsigned long ip
, unsigned long sym_flags
)
776 if (sym_flags
& TRACE_ITER_SYM_OFFSET
)
777 seq_print_sym_offset(m
, "%s", ip
);
779 seq_print_sym_short(m
, "%s", ip
);
781 if (sym_flags
& TRACE_ITER_SYM_ADDR
)
782 seq_printf(m
, " <" IP_FMT
">", ip
);
785 static notrace
void print_lat_help_header(struct seq_file
*m
)
787 seq_puts(m
, "# _------=> CPU# \n");
788 seq_puts(m
, "# / _-----=> irqs-off \n");
789 seq_puts(m
, "# | / _----=> need-resched \n");
790 seq_puts(m
, "# || / _---=> hardirq/softirq \n");
791 seq_puts(m
, "# ||| / _--=> preempt-depth \n");
792 seq_puts(m
, "# |||| / \n");
793 seq_puts(m
, "# ||||| delay \n");
794 seq_puts(m
, "# cmd pid ||||| time | caller \n");
795 seq_puts(m
, "# \\ / ||||| \\ | / \n");
798 static notrace
void print_func_help_header(struct seq_file
*m
)
800 seq_puts(m
, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
801 seq_puts(m
, "# | | | | |\n");
806 print_trace_header(struct seq_file
*m
, struct trace_iterator
*iter
)
808 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
809 struct trace_array
*tr
= iter
->tr
;
810 struct trace_array_cpu
*data
= tr
->data
[tr
->cpu
];
811 struct tracer
*type
= current_trace
;
812 unsigned long total
= 0;
813 unsigned long entries
= 0;
815 const char *name
= "preemption";
820 for_each_possible_cpu(cpu
) {
821 if (head_page(tr
->data
[cpu
])) {
822 total
+= tr
->data
[cpu
]->trace_idx
;
823 if (tr
->data
[cpu
]->trace_idx
> tr
->entries
)
824 entries
+= tr
->entries
;
826 entries
+= tr
->data
[cpu
]->trace_idx
;
830 seq_printf(m
, "%s latency trace v1.1.5 on %s\n",
832 seq_puts(m
, "-----------------------------------"
833 "---------------------------------\n");
834 seq_printf(m
, " latency: %lu us, #%lu/%lu, CPU#%d |"
835 " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
836 nsecs_to_usecs(data
->saved_latency
),
840 #if defined(CONFIG_PREEMPT_NONE)
842 #elif defined(CONFIG_PREEMPT_VOLUNTARY)
844 #elif defined(CONFIG_PREEMPT_DESKTOP)
849 /* These are reserved for later use */
852 seq_printf(m
, " #P:%d)\n", num_online_cpus());
856 seq_puts(m
, " -----------------\n");
857 seq_printf(m
, " | task: %.16s-%d "
858 "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
859 data
->comm
, data
->pid
, data
->uid
, data
->nice
,
860 data
->policy
, data
->rt_priority
);
861 seq_puts(m
, " -----------------\n");
863 if (data
->critical_start
) {
864 seq_puts(m
, " => started at: ");
865 seq_print_ip_sym(m
, data
->critical_start
, sym_flags
);
866 seq_puts(m
, "\n => ended at: ");
867 seq_print_ip_sym(m
, data
->critical_end
, sym_flags
);
875 lat_print_generic(struct seq_file
*m
, struct trace_entry
*entry
, int cpu
)
877 int hardirq
, softirq
;
880 comm
= trace_find_cmdline(entry
->pid
);
882 seq_printf(m
, "%8.8s-%-5d ", comm
, entry
->pid
);
883 seq_printf(m
, "%d", cpu
);
884 seq_printf(m
, "%c%c",
885 (entry
->flags
& TRACE_FLAG_IRQS_OFF
) ? 'd' : '.',
886 ((entry
->flags
& TRACE_FLAG_NEED_RESCHED
) ? 'N' : '.'));
888 hardirq
= entry
->flags
& TRACE_FLAG_HARDIRQ
;
889 softirq
= entry
->flags
& TRACE_FLAG_SOFTIRQ
;
890 if (hardirq
&& softirq
)
903 if (entry
->preempt_count
)
904 seq_printf(m
, "%x", entry
->preempt_count
);
909 unsigned long preempt_mark_thresh
= 100;
912 lat_print_timestamp(struct seq_file
*m
, unsigned long long abs_usecs
,
913 unsigned long rel_usecs
)
915 seq_printf(m
, " %4lldus", abs_usecs
);
916 if (rel_usecs
> preempt_mark_thresh
)
918 else if (rel_usecs
> 1)
924 static const char state_to_char
[] = TASK_STATE_TO_CHAR_STR
;
927 print_lat_fmt(struct seq_file
*m
, struct trace_iterator
*iter
,
928 unsigned int trace_idx
, int cpu
)
930 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
931 struct trace_entry
*next_entry
= find_next_entry(iter
, NULL
);
932 unsigned long verbose
= (trace_flags
& TRACE_ITER_VERBOSE
);
933 struct trace_entry
*entry
= iter
->ent
;
934 unsigned long abs_usecs
;
935 unsigned long rel_usecs
;
941 rel_usecs
= ns2usecs(next_entry
->t
- entry
->t
);
942 abs_usecs
= ns2usecs(entry
->t
- iter
->tr
->time_start
);
945 comm
= trace_find_cmdline(entry
->pid
);
946 seq_printf(m
, "%16s %5d %d %d %08x %08x [%08lx]"
947 " %ld.%03ldms (+%ld.%03ldms): ",
949 entry
->pid
, cpu
, entry
->flags
,
950 entry
->preempt_count
, trace_idx
,
953 abs_usecs
% 1000, rel_usecs
/1000, rel_usecs
% 1000);
955 lat_print_generic(m
, entry
, cpu
);
956 lat_print_timestamp(m
, abs_usecs
, rel_usecs
);
958 switch (entry
->type
) {
960 seq_print_ip_sym(m
, entry
->fn
.ip
, sym_flags
);
962 seq_print_ip_sym(m
, entry
->fn
.parent_ip
, sym_flags
);
966 S
= entry
->ctx
.prev_state
< sizeof(state_to_char
) ?
967 state_to_char
[entry
->ctx
.prev_state
] : 'X';
968 comm
= trace_find_cmdline(entry
->ctx
.next_pid
);
969 seq_printf(m
, " %d:%d:%c --> %d:%d %s\n",
971 entry
->ctx
.prev_prio
,
974 entry
->ctx
.next_prio
,
978 seq_printf(m
, "Unknown type %d\n", entry
->type
);
982 static notrace
void sync_time_offset(struct trace_iterator
*iter
)
984 struct trace_array_cpu
*prev_array
, *array
;
985 struct trace_entry
*prev_entry
, *entry
;
989 prev_entry
= iter
->prev_ent
;
993 prev_array
= iter
->tr
->data
[iter
->prev_cpu
];
994 array
= iter
->tr
->data
[iter
->cpu
];
996 prev_t
= prev_entry
->t
+ prev_array
->time_offset
;
997 t
= entry
->t
+ array
->time_offset
;
1000 * If time goes backwards we increase the offset of
1001 * the current array, to not have observable time warps.
1002 * This will quickly synchronize the time offsets of
1006 array
->time_offset
+= prev_t
- t
;
1010 print_trace_fmt(struct seq_file
*m
, struct trace_iterator
*iter
)
1012 unsigned long sym_flags
= (trace_flags
& TRACE_ITER_SYM_MASK
);
1013 struct trace_entry
*entry
;
1014 unsigned long usec_rem
;
1015 unsigned long long t
;
1020 sync_time_offset(iter
);
1023 comm
= trace_find_cmdline(iter
->ent
->pid
);
1025 t
= ns2usecs(entry
->t
+ iter
->tr
->data
[iter
->cpu
]->time_offset
);
1026 usec_rem
= do_div(t
, 1000000ULL);
1027 secs
= (unsigned long)t
;
1029 seq_printf(m
, "%16s-%-5d ", comm
, entry
->pid
);
1030 seq_printf(m
, "[%02d] ", iter
->cpu
);
1031 seq_printf(m
, "%5lu.%06lu: ", secs
, usec_rem
);
1033 switch (entry
->type
) {
1035 seq_print_ip_sym(m
, entry
->fn
.ip
, sym_flags
);
1036 if ((sym_flags
& TRACE_ITER_PRINT_PARENT
) &&
1037 entry
->fn
.parent_ip
) {
1038 seq_printf(m
, " <-");
1039 seq_print_ip_sym(m
, entry
->fn
.parent_ip
, sym_flags
);
1041 seq_printf(m
, "\n");
1044 S
= entry
->ctx
.prev_state
< sizeof(state_to_char
) ?
1045 state_to_char
[entry
->ctx
.prev_state
] : 'X';
1046 seq_printf(m
, " %d:%d:%c ==> %d:%d\n",
1047 entry
->ctx
.prev_pid
,
1048 entry
->ctx
.prev_prio
,
1050 entry
->ctx
.next_pid
,
1051 entry
->ctx
.next_prio
);
1056 static int trace_empty(struct trace_iterator
*iter
)
1058 struct trace_array_cpu
*data
;
1061 for_each_possible_cpu(cpu
) {
1062 data
= iter
->tr
->data
[cpu
];
1064 if (head_page(data
) && data
->trace_idx
)
1070 static int s_show(struct seq_file
*m
, void *v
)
1072 struct trace_iterator
*iter
= v
;
1074 if (iter
->ent
== NULL
) {
1076 seq_printf(m
, "# tracer: %s\n", iter
->trace
->name
);
1079 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
) {
1080 /* print nothing if the buffers are empty */
1081 if (trace_empty(iter
))
1083 print_trace_header(m
, iter
);
1084 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
1085 print_lat_help_header(m
);
1087 if (!(trace_flags
& TRACE_ITER_VERBOSE
))
1088 print_func_help_header(m
);
1091 if (iter
->iter_flags
& TRACE_FILE_LAT_FMT
)
1092 print_lat_fmt(m
, iter
, iter
->idx
, iter
->cpu
);
1094 print_trace_fmt(m
, iter
);
1100 static struct seq_operations tracer_seq_ops
= {
1107 static struct trace_iterator notrace
*
1108 __tracing_open(struct inode
*inode
, struct file
*file
, int *ret
)
1110 struct trace_iterator
*iter
;
1112 if (tracing_disabled
) {
1117 iter
= kzalloc(sizeof(*iter
), GFP_KERNEL
);
1123 mutex_lock(&trace_types_lock
);
1124 if (current_trace
&& current_trace
->print_max
)
1127 iter
->tr
= inode
->i_private
;
1128 iter
->trace
= current_trace
;
1131 /* TODO stop tracer */
1132 *ret
= seq_open(file
, &tracer_seq_ops
);
1134 struct seq_file
*m
= file
->private_data
;
1137 /* stop the trace while dumping */
1141 if (iter
->trace
&& iter
->trace
->open
)
1142 iter
->trace
->open(iter
);
1147 mutex_unlock(&trace_types_lock
);
1153 int tracing_open_generic(struct inode
*inode
, struct file
*filp
)
1155 if (tracing_disabled
)
1158 filp
->private_data
= inode
->i_private
;
1162 int tracing_release(struct inode
*inode
, struct file
*file
)
1164 struct seq_file
*m
= (struct seq_file
*)file
->private_data
;
1165 struct trace_iterator
*iter
= m
->private;
1167 mutex_lock(&trace_types_lock
);
1168 if (iter
->trace
&& iter
->trace
->close
)
1169 iter
->trace
->close(iter
);
1171 /* reenable tracing if it was previously enabled */
1174 mutex_unlock(&trace_types_lock
);
1176 seq_release(inode
, file
);
1181 static int tracing_open(struct inode
*inode
, struct file
*file
)
1185 __tracing_open(inode
, file
, &ret
);
1190 static int tracing_lt_open(struct inode
*inode
, struct file
*file
)
1192 struct trace_iterator
*iter
;
1195 iter
= __tracing_open(inode
, file
, &ret
);
1198 iter
->iter_flags
|= TRACE_FILE_LAT_FMT
;
1204 static notrace
void *
1205 t_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
1207 struct tracer
*t
= m
->private;
1219 static void *t_start(struct seq_file
*m
, loff_t
*pos
)
1221 struct tracer
*t
= m
->private;
1224 mutex_lock(&trace_types_lock
);
1225 for (; t
&& l
< *pos
; t
= t_next(m
, t
, &l
))
1231 static void t_stop(struct seq_file
*m
, void *p
)
1233 mutex_unlock(&trace_types_lock
);
1236 static int t_show(struct seq_file
*m
, void *v
)
1238 struct tracer
*t
= v
;
1243 seq_printf(m
, "%s", t
->name
);
1252 static struct seq_operations show_traces_seq_ops
= {
1259 static int show_traces_open(struct inode
*inode
, struct file
*file
)
1263 if (tracing_disabled
)
1266 ret
= seq_open(file
, &show_traces_seq_ops
);
1268 struct seq_file
*m
= file
->private_data
;
1269 m
->private = trace_types
;
1275 static struct file_operations tracing_fops
= {
1276 .open
= tracing_open
,
1278 .llseek
= seq_lseek
,
1279 .release
= tracing_release
,
1282 static struct file_operations tracing_lt_fops
= {
1283 .open
= tracing_lt_open
,
1285 .llseek
= seq_lseek
,
1286 .release
= tracing_release
,
1289 static struct file_operations show_traces_fops
= {
1290 .open
= show_traces_open
,
1292 .release
= seq_release
,
1296 tracing_iter_ctrl_read(struct file
*filp
, char __user
*ubuf
,
1297 size_t cnt
, loff_t
*ppos
)
1304 /* calulate max size */
1305 for (i
= 0; trace_options
[i
]; i
++) {
1306 len
+= strlen(trace_options
[i
]);
1307 len
+= 3; /* "no" and space */
1310 /* +2 for \n and \0 */
1311 buf
= kmalloc(len
+ 2, GFP_KERNEL
);
1315 for (i
= 0; trace_options
[i
]; i
++) {
1316 if (trace_flags
& (1 << i
))
1317 r
+= sprintf(buf
+ r
, "%s ", trace_options
[i
]);
1319 r
+= sprintf(buf
+ r
, "no%s ", trace_options
[i
]);
1322 r
+= sprintf(buf
+ r
, "\n");
1323 WARN_ON(r
>= len
+ 2);
1325 r
= simple_read_from_buffer(ubuf
, cnt
, ppos
,
1334 tracing_iter_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
1335 size_t cnt
, loff_t
*ppos
)
1345 if (copy_from_user(&buf
, ubuf
, cnt
))
1350 if (strncmp(buf
, "no", 2) == 0) {
1355 for (i
= 0; trace_options
[i
]; i
++) {
1356 int len
= strlen(trace_options
[i
]);
1358 if (strncmp(cmp
, trace_options
[i
], len
) == 0) {
1360 trace_flags
&= ~(1 << i
);
1362 trace_flags
|= (1 << i
);
1372 static struct file_operations tracing_iter_fops
= {
1373 .open
= tracing_open_generic
,
1374 .read
= tracing_iter_ctrl_read
,
1375 .write
= tracing_iter_ctrl_write
,
1378 static const char readme_msg
[] =
1379 "tracing mini-HOWTO:\n\n"
1381 "# mount -t debugfs nodev /debug\n\n"
1382 "# cat /debug/tracing/available_tracers\n"
1383 "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
1384 "# cat /debug/tracing/current_tracer\n"
1386 "# echo sched_switch > /debug/tracing/current_tracer\n"
1387 "# cat /debug/tracing/current_tracer\n"
1389 "# cat /debug/tracing/iter_ctrl\n"
1390 "noprint-parent nosym-offset nosym-addr noverbose\n"
1391 "# echo print-parent > /debug/tracing/iter_ctrl\n"
1392 "# echo 1 > /debug/tracing/tracing_enabled\n"
1393 "# cat /debug/tracing/trace > /tmp/trace.txt\n"
1394 "echo 0 > /debug/tracing/tracing_enabled\n"
1398 tracing_readme_read(struct file
*filp
, char __user
*ubuf
,
1399 size_t cnt
, loff_t
*ppos
)
1401 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
1402 readme_msg
, strlen(readme_msg
));
1405 static struct file_operations tracing_readme_fops
= {
1406 .open
= tracing_open_generic
,
1407 .read
= tracing_readme_read
,
1412 tracing_ctrl_read(struct file
*filp
, char __user
*ubuf
,
1413 size_t cnt
, loff_t
*ppos
)
1415 struct trace_array
*tr
= filp
->private_data
;
1419 r
= sprintf(buf
, "%ld\n", tr
->ctrl
);
1420 return simple_read_from_buffer(ubuf
, cnt
, ppos
, buf
, r
);
1424 tracing_ctrl_write(struct file
*filp
, const char __user
*ubuf
,
1425 size_t cnt
, loff_t
*ppos
)
1427 struct trace_array
*tr
= filp
->private_data
;
1434 if (copy_from_user(&buf
, ubuf
, cnt
))
1439 val
= simple_strtoul(buf
, NULL
, 10);
1443 mutex_lock(&trace_types_lock
);
1444 if (tr
->ctrl
^ val
) {
1452 if (current_trace
&& current_trace
->ctrl_update
)
1453 current_trace
->ctrl_update(tr
);
1455 mutex_unlock(&trace_types_lock
);
1463 tracing_set_trace_read(struct file
*filp
, char __user
*ubuf
,
1464 size_t cnt
, loff_t
*ppos
)
1466 char buf
[max_tracer_type_len
+2];
1469 mutex_lock(&trace_types_lock
);
1471 r
= sprintf(buf
, "%s\n", current_trace
->name
);
1473 r
= sprintf(buf
, "\n");
1474 mutex_unlock(&trace_types_lock
);
1476 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
1481 tracing_set_trace_write(struct file
*filp
, const char __user
*ubuf
,
1482 size_t cnt
, loff_t
*ppos
)
1484 struct trace_array
*tr
= &global_trace
;
1486 char buf
[max_tracer_type_len
+1];
1489 if (cnt
> max_tracer_type_len
)
1490 cnt
= max_tracer_type_len
;
1492 if (copy_from_user(&buf
, ubuf
, cnt
))
1497 /* strip ending whitespace. */
1498 for (i
= cnt
- 1; i
> 0 && isspace(buf
[i
]); i
--)
1501 mutex_lock(&trace_types_lock
);
1502 for (t
= trace_types
; t
; t
= t
->next
) {
1503 if (strcmp(t
->name
, buf
) == 0)
1506 if (!t
|| t
== current_trace
)
1509 if (current_trace
&& current_trace
->reset
)
1510 current_trace
->reset(tr
);
1517 mutex_unlock(&trace_types_lock
);
1525 tracing_max_lat_read(struct file
*filp
, char __user
*ubuf
,
1526 size_t cnt
, loff_t
*ppos
)
1528 unsigned long *ptr
= filp
->private_data
;
1532 r
= snprintf(buf
, 64, "%ld\n",
1533 *ptr
== (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr
));
1536 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
1541 tracing_max_lat_write(struct file
*filp
, const char __user
*ubuf
,
1542 size_t cnt
, loff_t
*ppos
)
1544 long *ptr
= filp
->private_data
;
1551 if (copy_from_user(&buf
, ubuf
, cnt
))
1556 val
= simple_strtoul(buf
, NULL
, 10);
1563 static struct file_operations tracing_max_lat_fops
= {
1564 .open
= tracing_open_generic
,
1565 .read
= tracing_max_lat_read
,
1566 .write
= tracing_max_lat_write
,
1569 static struct file_operations tracing_ctrl_fops
= {
1570 .open
= tracing_open_generic
,
1571 .read
= tracing_ctrl_read
,
1572 .write
= tracing_ctrl_write
,
1575 static struct file_operations set_tracer_fops
= {
1576 .open
= tracing_open_generic
,
1577 .read
= tracing_set_trace_read
,
1578 .write
= tracing_set_trace_write
,
1581 #ifdef CONFIG_DYNAMIC_FTRACE
1584 tracing_read_long(struct file
*filp
, char __user
*ubuf
,
1585 size_t cnt
, loff_t
*ppos
)
1587 unsigned long *p
= filp
->private_data
;
1591 r
= sprintf(buf
, "%ld\n", *p
);
1592 return simple_read_from_buffer(ubuf
, cnt
, ppos
,
1596 static struct file_operations tracing_read_long_fops
= {
1597 .open
= tracing_open_generic
,
1598 .read
= tracing_read_long
,
1602 static struct dentry
*d_tracer
;
1604 struct dentry
*tracing_init_dentry(void)
1611 d_tracer
= debugfs_create_dir("tracing", NULL
);
1613 if (!d_tracer
&& !once
) {
1615 pr_warning("Could not create debugfs directory 'tracing'\n");
1622 #ifdef CONFIG_FTRACE_SELFTEST
1623 /* Let selftest have access to static functions in this file */
1624 #include "trace_selftest.c"
1627 static __init
void tracer_init_debugfs(void)
1629 struct dentry
*d_tracer
;
1630 struct dentry
*entry
;
1632 d_tracer
= tracing_init_dentry();
1634 entry
= debugfs_create_file("tracing_enabled", 0644, d_tracer
,
1635 &global_trace
, &tracing_ctrl_fops
);
1637 pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
1639 entry
= debugfs_create_file("iter_ctrl", 0644, d_tracer
,
1640 NULL
, &tracing_iter_fops
);
1642 pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
1644 entry
= debugfs_create_file("latency_trace", 0444, d_tracer
,
1645 &global_trace
, &tracing_lt_fops
);
1647 pr_warning("Could not create debugfs 'latency_trace' entry\n");
1649 entry
= debugfs_create_file("trace", 0444, d_tracer
,
1650 &global_trace
, &tracing_fops
);
1652 pr_warning("Could not create debugfs 'trace' entry\n");
1654 entry
= debugfs_create_file("available_tracers", 0444, d_tracer
,
1655 &global_trace
, &show_traces_fops
);
1657 pr_warning("Could not create debugfs 'trace' entry\n");
1659 entry
= debugfs_create_file("current_tracer", 0444, d_tracer
,
1660 &global_trace
, &set_tracer_fops
);
1662 pr_warning("Could not create debugfs 'trace' entry\n");
1664 entry
= debugfs_create_file("tracing_max_latency", 0644, d_tracer
,
1665 &tracing_max_latency
,
1666 &tracing_max_lat_fops
);
1668 pr_warning("Could not create debugfs "
1669 "'tracing_max_latency' entry\n");
1671 entry
= debugfs_create_file("tracing_thresh", 0644, d_tracer
,
1672 &tracing_thresh
, &tracing_max_lat_fops
);
1674 pr_warning("Could not create debugfs "
1675 "'tracing_threash' entry\n");
1676 entry
= debugfs_create_file("README", 0644, d_tracer
,
1677 NULL
, &tracing_readme_fops
);
1679 pr_warning("Could not create debugfs 'README' entry\n");
1682 #ifdef CONFIG_DYNAMIC_FTRACE
1683 entry
= debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer
,
1684 &ftrace_update_tot_cnt
,
1685 &tracing_read_long_fops
);
1687 pr_warning("Could not create debugfs "
1688 "'dyn_ftrace_total_info' entry\n");
1692 /* dummy trace to disable tracing */
1693 static struct tracer no_tracer __read_mostly
=
1698 static int trace_alloc_page(void)
1700 struct trace_array_cpu
*data
;
1701 struct page
*page
, *tmp
;
1706 /* first allocate a page for each CPU */
1707 for_each_possible_cpu(i
) {
1708 array
= (void *)__get_free_page(GFP_KERNEL
);
1709 if (array
== NULL
) {
1710 printk(KERN_ERR
"tracer: failed to allocate page"
1711 "for trace buffer!\n");
1715 page
= virt_to_page(array
);
1716 list_add(&page
->lru
, &pages
);
1718 /* Only allocate if we are actually using the max trace */
1719 #ifdef CONFIG_TRACER_MAX_TRACE
1720 array
= (void *)__get_free_page(GFP_KERNEL
);
1721 if (array
== NULL
) {
1722 printk(KERN_ERR
"tracer: failed to allocate page"
1723 "for trace buffer!\n");
1726 page
= virt_to_page(array
);
1727 list_add(&page
->lru
, &pages
);
1731 /* Now that we successfully allocate a page per CPU, add them */
1732 for_each_possible_cpu(i
) {
1733 data
= global_trace
.data
[i
];
1734 page
= list_entry(pages
.next
, struct page
, lru
);
1735 list_del_init(&page
->lru
);
1736 list_add_tail(&page
->lru
, &data
->trace_pages
);
1739 #ifdef CONFIG_TRACER_MAX_TRACE
1740 data
= max_tr
.data
[i
];
1741 page
= list_entry(pages
.next
, struct page
, lru
);
1742 list_del_init(&page
->lru
);
1743 list_add_tail(&page
->lru
, &data
->trace_pages
);
1747 global_trace
.entries
+= ENTRIES_PER_PAGE
;
1752 list_for_each_entry_safe(page
, tmp
, &pages
, lru
) {
1753 list_del_init(&page
->lru
);
1759 __init
static int tracer_alloc_buffers(void)
1761 struct trace_array_cpu
*data
;
1768 /* Allocate the first page for all buffers */
1769 for_each_possible_cpu(i
) {
1770 data
= global_trace
.data
[i
] = &per_cpu(global_trace_cpu
, i
);
1771 max_tr
.data
[i
] = &per_cpu(max_data
, i
);
1773 array
= (void *)__get_free_page(GFP_KERNEL
);
1774 if (array
== NULL
) {
1775 printk(KERN_ERR
"tracer: failed to allocate page"
1776 "for trace buffer!\n");
1780 /* set the array to the list */
1781 INIT_LIST_HEAD(&data
->trace_pages
);
1782 page
= virt_to_page(array
);
1783 list_add(&page
->lru
, &data
->trace_pages
);
1784 /* use the LRU flag to differentiate the two buffers */
1787 /* Only allocate if we are actually using the max trace */
1788 #ifdef CONFIG_TRACER_MAX_TRACE
1789 array
= (void *)__get_free_page(GFP_KERNEL
);
1790 if (array
== NULL
) {
1791 printk(KERN_ERR
"tracer: failed to allocate page"
1792 "for trace buffer!\n");
1796 INIT_LIST_HEAD(&max_tr
.data
[i
]->trace_pages
);
1797 page
= virt_to_page(array
);
1798 list_add(&page
->lru
, &max_tr
.data
[i
]->trace_pages
);
1804 * Since we allocate by orders of pages, we may be able to
1807 global_trace
.entries
= ENTRIES_PER_PAGE
;
1810 while (global_trace
.entries
< trace_nr_entries
) {
1811 if (trace_alloc_page())
1815 max_tr
.entries
= global_trace
.entries
;
1817 pr_info("tracer: %d pages allocated for %ld",
1818 pages
, trace_nr_entries
);
1819 pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE
);
1820 pr_info(" actual entries %ld\n", global_trace
.entries
);
1822 tracer_init_debugfs();
1824 trace_init_cmdlines();
1826 register_tracer(&no_tracer
);
1827 current_trace
= &no_tracer
;
1829 /* All seems OK, enable tracing */
1830 tracing_disabled
= 0;
1835 for (i
-- ; i
>= 0; i
--) {
1836 struct page
*page
, *tmp
;
1837 struct trace_array_cpu
*data
= global_trace
.data
[i
];
1840 list_for_each_entry_safe(page
, tmp
,
1841 &data
->trace_pages
, lru
) {
1842 list_del_init(&page
->lru
);
1847 #ifdef CONFIG_TRACER_MAX_TRACE
1848 data
= max_tr
.data
[i
];
1850 list_for_each_entry_safe(page
, tmp
,
1851 &data
->trace_pages
, lru
) {
1852 list_del_init(&page
->lru
);
1861 fs_initcall(tracer_alloc_buffers
);