ftrace: fix time offset
fix time offset calculations and ordering, plus make code more consistent. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Ingo Molnar
Thomas Gleixner
parent
77a2b37d22
commit
4e3c3333f3
2 changed files with 63 additions and 21 deletions
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@ -120,7 +120,7 @@ static DEFINE_SPINLOCK(ftrace_max_lock);
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* structure. (this way the maximum trace is permanently saved,
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* for later retrieval via /debugfs/tracing/latency_trace)
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*/
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static void notrace
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static notrace void
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__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
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{
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struct trace_array_cpu *data = tr->data[cpu];
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@ -333,15 +333,16 @@ void unregister_tracer(struct tracer *type)
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mutex_unlock(&trace_types_lock);
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}
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void notrace tracing_reset(struct trace_array_cpu *data)
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notrace void tracing_reset(struct trace_array_cpu *data)
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{
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data->trace_idx = 0;
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data->trace_current = head_page(data);
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data->trace_current_idx = 0;
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data->time_offset = 0;
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}
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#ifdef CONFIG_FTRACE
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static void notrace
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static notrace void
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function_trace_call(unsigned long ip, unsigned long parent_ip)
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{
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struct trace_array *tr = &global_trace;
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@ -398,7 +399,7 @@ static void trace_init_cmdlines(void)
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notrace void trace_stop_cmdline_recording(void);
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static void notrace trace_save_cmdline(struct task_struct *tsk)
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static notrace void trace_save_cmdline(struct task_struct *tsk)
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{
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unsigned map;
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unsigned idx;
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@ -624,6 +625,7 @@ static void *find_next_entry_inc(struct trace_iterator *iter)
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iter->idx++;
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iter->next_idx[next_cpu]++;
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iter->next_page_idx[next_cpu]++;
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if (iter->next_page_idx[next_cpu] >= ENTRIES_PER_PAGE) {
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struct trace_array_cpu *data = iter->tr->data[next_cpu];
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@ -635,19 +637,21 @@ static void *find_next_entry_inc(struct trace_iterator *iter)
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data->trace_pages.next;
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}
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}
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iter->prev_ent = iter->ent;
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iter->prev_cpu = iter->cpu;
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iter->ent = next;
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iter->cpu = next_cpu;
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return next ? iter : NULL;
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}
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static void notrace *
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s_next(struct seq_file *m, void *v, loff_t *pos)
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static notrace void *s_next(struct seq_file *m, void *v, loff_t *pos)
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{
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struct trace_iterator *iter = m->private;
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void *ent;
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void *last_ent = iter->ent;
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int i = (int)*pos;
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void *ent;
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(*pos)++;
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@ -693,6 +697,8 @@ static void *s_start(struct seq_file *m, loff_t *pos)
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iter->ent = NULL;
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iter->cpu = 0;
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iter->idx = -1;
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iter->prev_ent = NULL;
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iter->prev_cpu = -1;
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for_each_possible_cpu(i) {
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iter->next_idx[i] = 0;
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@ -752,7 +758,7 @@ seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address)
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# define IP_FMT "%016lx"
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#endif
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static void notrace
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static notrace void
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seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
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{
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if (!ip) {
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@ -769,7 +775,7 @@ seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
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seq_printf(m, " <" IP_FMT ">", ip);
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}
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static void notrace print_lat_help_header(struct seq_file *m)
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static notrace void print_lat_help_header(struct seq_file *m)
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{
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seq_puts(m, "# _------=> CPU# \n");
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seq_puts(m, "# / _-----=> irqs-off \n");
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@ -782,14 +788,14 @@ static void notrace print_lat_help_header(struct seq_file *m)
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seq_puts(m, "# \\ / ||||| \\ | / \n");
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}
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static void notrace print_func_help_header(struct seq_file *m)
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static notrace void print_func_help_header(struct seq_file *m)
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{
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seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
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seq_puts(m, "# | | | | |\n");
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}
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static void notrace
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static notrace void
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print_trace_header(struct seq_file *m, struct trace_iterator *iter)
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{
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unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
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@ -858,7 +864,7 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter)
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seq_puts(m, "\n");
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}
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static void notrace
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static notrace void
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lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
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{
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int hardirq, softirq;
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@ -895,7 +901,7 @@ lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
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unsigned long preempt_mark_thresh = 100;
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static void notrace
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static notrace void
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lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
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unsigned long rel_usecs)
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{
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@ -910,7 +916,7 @@ lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
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static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
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static void notrace
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static notrace void
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print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
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unsigned int trace_idx, int cpu)
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{
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@ -966,20 +972,50 @@ print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
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}
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}
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static void notrace
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static notrace void sync_time_offset(struct trace_iterator *iter)
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{
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struct trace_array_cpu *prev_array, *array;
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struct trace_entry *prev_entry, *entry;
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cycle_t prev_t, t;
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entry = iter->ent;
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prev_entry = iter->prev_ent;
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if (!prev_entry)
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return;
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prev_array = iter->tr->data[iter->prev_cpu];
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array = iter->tr->data[iter->cpu];
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prev_t = prev_entry->t + prev_array->time_offset;
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t = entry->t + array->time_offset;
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/*
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* If time goes backwards we increase the offset of
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* the current array, to not have observable time warps.
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* This will quickly synchronize the time offsets of
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* multiple CPUs:
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*/
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if (t < prev_t)
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array->time_offset += prev_t - t;
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}
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static notrace void
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print_trace_fmt(struct seq_file *m, struct trace_iterator *iter)
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{
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unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
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struct trace_entry *entry = iter->ent;
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struct trace_entry *entry;
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unsigned long usec_rem;
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unsigned long long t;
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unsigned long secs;
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char *comm;
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int S;
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sync_time_offset(iter);
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entry = iter->ent;
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comm = trace_find_cmdline(iter->ent->pid);
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t = ns2usecs(entry->t);
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t = ns2usecs(entry->t + iter->tr->data[iter->cpu]->time_offset);
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usec_rem = do_div(t, 1000000ULL);
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secs = (unsigned long)t;
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@ -1158,7 +1194,7 @@ static int tracing_lt_open(struct inode *inode, struct file *file)
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}
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static void notrace *
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static notrace void *
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t_next(struct seq_file *m, void *v, loff_t *pos)
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{
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struct tracer *t = m->private;
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@ -1374,8 +1410,7 @@ tracing_ctrl_read(struct file *filp, char __user *ubuf,
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int r;
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r = sprintf(buf, "%ld\n", tr->ctrl);
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return simple_read_from_buffer(ubuf, cnt, ppos,
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buf, r);
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return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
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}
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static ssize_t
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@ -56,6 +56,8 @@ struct trace_array_cpu {
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void *trace_current;
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struct list_head trace_pages;
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atomic_t disabled;
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cycle_t time_offset;
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/* these fields get copied into max-trace: */
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unsigned trace_current_idx;
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unsigned long trace_idx;
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@ -114,14 +116,19 @@ struct tracer {
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struct trace_iterator {
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struct trace_array *tr;
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struct tracer *trace;
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struct trace_entry *ent;
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int cpu;
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struct trace_entry *prev_ent;
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int prev_cpu;
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unsigned long iter_flags;
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loff_t pos;
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unsigned long next_idx[NR_CPUS];
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struct list_head *next_page[NR_CPUS];
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unsigned next_page_idx[NR_CPUS];
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long idx;
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int cpu;
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};
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void notrace tracing_reset(struct trace_array_cpu *data);
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