--- /dev/null
+/*
+ * ring buffer based function tracer
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ * Copyright (C) 2008 Ingo Molnar <mingo@redhat.com>
+ *
+ * Originally taken from the RT patch by:
+ * Arnaldo Carvalho de Melo <acme@redhat.com>
+ *
+ * Based on code from the latency_tracer, that is:
+ * Copyright (C) 2004-2006 Ingo Molnar
+ * Copyright (C) 2004 William Lee Irwin III
+ */
+#include <linux/utsrelease.h>
+#include <linux/kallsyms.h>
+#include <linux/seq_file.h>
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/linkage.h>
+#include <linux/uaccess.h>
+#include <linux/ftrace.h>
+#include <linux/module.h>
+#include <linux/percpu.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/gfp.h>
+#include <linux/fs.h>
+
+#include "trace.h"
+
+unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX;
+unsigned long __read_mostly tracing_thresh;
+
+static long notrace
+ns2usecs(cycle_t nsec)
+{
+ nsec += 500;
+ do_div(nsec, 1000);
+ return nsec;
+}
+
+static atomic_t tracer_counter;
+static struct trace_array global_trace;
+
+static DEFINE_PER_CPU(struct trace_array_cpu, global_trace_cpu);
+
+static struct trace_array max_tr;
+
+static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
+
+static int tracer_enabled;
+static unsigned long trace_nr_entries = 4096UL;
+
+static struct tracer *trace_types __read_mostly;
+static struct tracer *current_trace __read_mostly;
+static int max_tracer_type_len;
+
+static DEFINE_MUTEX(trace_types_lock);
+
+static int __init set_nr_entries(char *str)
+{
+ if (!str)
+ return 0;
+ trace_nr_entries = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("trace_entries=", set_nr_entries);
+
+enum trace_type {
+ __TRACE_FIRST_TYPE = 0,
+
+ TRACE_FN,
+ TRACE_CTX,
+
+ __TRACE_LAST_TYPE
+};
+
+enum trace_flag_type {
+ TRACE_FLAG_IRQS_OFF = 0x01,
+ TRACE_FLAG_NEED_RESCHED = 0x02,
+ TRACE_FLAG_HARDIRQ = 0x04,
+ TRACE_FLAG_SOFTIRQ = 0x08,
+};
+
+enum trace_iterator_flags {
+ TRACE_ITER_PRINT_PARENT = 0x01,
+ TRACE_ITER_SYM_OFFSET = 0x02,
+ TRACE_ITER_SYM_ADDR = 0x04,
+ TRACE_ITER_VERBOSE = 0x08,
+};
+
+#define TRACE_ITER_SYM_MASK \
+ (TRACE_ITER_PRINT_PARENT|TRACE_ITER_SYM_OFFSET|TRACE_ITER_SYM_ADDR)
+
+/* These must match the bit postions above */
+static const char *trace_options[] = {
+ "print-parent",
+ "sym-offset",
+ "sym-addr",
+ "verbose",
+ NULL
+};
+
+static unsigned trace_flags;
+
+
+/*
+ * Copy the new maximum trace into the separate maximum-trace
+ * structure. (this way the maximum trace is permanently saved,
+ * for later retrieval via /debugfs/tracing/latency_trace)
+ */
+static void notrace
+__update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ struct trace_array_cpu *data = tr->data[cpu];
+
+ max_tr.cpu = cpu;
+ max_tr.time_start = data->preempt_timestamp;
+
+ data = max_tr.data[cpu];
+ data->saved_latency = tracing_max_latency;
+
+ memcpy(data->comm, tsk->comm, TASK_COMM_LEN);
+ data->pid = tsk->pid;
+ data->uid = tsk->uid;
+ data->nice = tsk->static_prio - 20 - MAX_RT_PRIO;
+ data->policy = tsk->policy;
+ data->rt_priority = tsk->rt_priority;
+
+ /* record this tasks comm */
+ tracing_record_cmdline(current);
+}
+
+notrace void
+update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ struct trace_array_cpu *data;
+ void *save_trace;
+ int i;
+
+ /* clear out all the previous traces */
+ for_each_possible_cpu(i) {
+ data = tr->data[i];
+ save_trace = max_tr.data[i]->trace;
+ memcpy(max_tr.data[i], data, sizeof(*data));
+ data->trace = save_trace;
+ }
+
+ __update_max_tr(tr, tsk, cpu);
+}
+
+/**
+ * update_max_tr_single - only copy one trace over, and reset the rest
+ * @tr - tracer
+ * @tsk - task with the latency
+ * @cpu - the cpu of the buffer to copy.
+ */
+notrace void
+update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
+{
+ struct trace_array_cpu *data = tr->data[cpu];
+ void *save_trace;
+ int i;
+
+ for_each_possible_cpu(i)
+ tracing_reset(max_tr.data[i]);
+
+ save_trace = max_tr.data[cpu]->trace;
+ memcpy(max_tr.data[cpu], data, sizeof(*data));
+ data->trace = save_trace;
+
+ __update_max_tr(tr, tsk, cpu);
+}
+
+int register_tracer(struct tracer *type)
+{
+ struct tracer *t;
+ int len;
+ int ret = 0;
+
+ if (!type->name) {
+ pr_info("Tracer must have a name\n");
+ return -1;
+ }
+
+ mutex_lock(&trace_types_lock);
+ for (t = trace_types; t; t = t->next) {
+ if (strcmp(type->name, t->name) == 0) {
+ /* already found */
+ pr_info("Trace %s already registered\n",
+ type->name);
+ ret = -1;
+ goto out;
+ }
+ }
+
+ type->next = trace_types;
+ trace_types = type;
+ len = strlen(type->name);
+ if (len > max_tracer_type_len)
+ max_tracer_type_len = len;
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
+void unregister_tracer(struct tracer *type)
+{
+ struct tracer **t;
+ int len;
+
+ mutex_lock(&trace_types_lock);
+ for (t = &trace_types; *t; t = &(*t)->next) {
+ if (*t == type)
+ goto found;
+ }
+ pr_info("Trace %s not registered\n", type->name);
+ goto out;
+
+ found:
+ *t = (*t)->next;
+ if (strlen(type->name) != max_tracer_type_len)
+ goto out;
+
+ max_tracer_type_len = 0;
+ for (t = &trace_types; *t; t = &(*t)->next) {
+ len = strlen((*t)->name);
+ if (len > max_tracer_type_len)
+ max_tracer_type_len = len;
+ }
+ out:
+ mutex_unlock(&trace_types_lock);
+}
+
+void notrace tracing_reset(struct trace_array_cpu *data)
+{
+ data->trace_idx = 0;
+ atomic_set(&data->underrun, 0);
+}
+
+#ifdef CONFIG_FTRACE
+static void notrace
+function_trace_call(unsigned long ip, unsigned long parent_ip)
+{
+ struct trace_array *tr = &global_trace;
+ struct trace_array_cpu *data;
+ unsigned long flags;
+ long disabled;
+ int cpu;
+
+ if (unlikely(!tracer_enabled))
+ return;
+
+ raw_local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+ disabled = atomic_inc_return(&data->disabled);
+
+ if (likely(disabled == 1))
+ ftrace(tr, data, ip, parent_ip, flags);
+
+ atomic_dec(&data->disabled);
+ raw_local_irq_restore(flags);
+}
+
+static struct ftrace_ops trace_ops __read_mostly =
+{
+ .func = function_trace_call,
+};
+#endif
+
+notrace void tracing_start_function_trace(void)
+{
+ register_ftrace_function(&trace_ops);
+}
+
+notrace void tracing_stop_function_trace(void)
+{
+ unregister_ftrace_function(&trace_ops);
+}
+
+#define SAVED_CMDLINES 128
+static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
+static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
+static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
+static int cmdline_idx;
+static DEFINE_SPINLOCK(trace_cmdline_lock);
+atomic_t trace_record_cmdline_disabled;
+
+static void trace_init_cmdlines(void)
+{
+ memset(&map_pid_to_cmdline, -1, sizeof(map_pid_to_cmdline));
+ memset(&map_cmdline_to_pid, -1, sizeof(map_cmdline_to_pid));
+ cmdline_idx = 0;
+}
+
+notrace void trace_stop_cmdline_recording(void);
+
+static void notrace trace_save_cmdline(struct task_struct *tsk)
+{
+ unsigned map;
+ unsigned idx;
+
+ if (!tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
+ return;
+
+ /*
+ * It's not the end of the world if we don't get
+ * the lock, but we also don't want to spin
+ * nor do we want to disable interrupts,
+ * so if we miss here, then better luck next time.
+ */
+ if (!spin_trylock(&trace_cmdline_lock))
+ return;
+
+ idx = map_pid_to_cmdline[tsk->pid];
+ if (idx >= SAVED_CMDLINES) {
+ idx = (cmdline_idx + 1) % SAVED_CMDLINES;
+
+ map = map_cmdline_to_pid[idx];
+ if (map <= PID_MAX_DEFAULT)
+ map_pid_to_cmdline[map] = (unsigned)-1;
+
+ map_pid_to_cmdline[tsk->pid] = idx;
+
+ cmdline_idx = idx;
+ }
+
+ memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
+
+ spin_unlock(&trace_cmdline_lock);
+}
+
+static notrace char *trace_find_cmdline(int pid)
+{
+ char *cmdline = "<...>";
+ unsigned map;
+
+ if (!pid)
+ return "<idle>";
+
+ if (pid > PID_MAX_DEFAULT)
+ goto out;
+
+ map = map_pid_to_cmdline[pid];
+ if (map >= SAVED_CMDLINES)
+ goto out;
+
+ cmdline = saved_cmdlines[map];
+
+ out:
+ return cmdline;
+}
+
+notrace void tracing_record_cmdline(struct task_struct *tsk)
+{
+ if (atomic_read(&trace_record_cmdline_disabled))
+ return;
+
+ trace_save_cmdline(tsk);
+}
+
+static inline notrace struct trace_entry *
+tracing_get_trace_entry(struct trace_array *tr,
+ struct trace_array_cpu *data)
+{
+ unsigned long idx, idx_next;
+ struct trace_entry *entry;
+
+ idx = data->trace_idx;
+ idx_next = idx + 1;
+
+ if (unlikely(idx_next >= tr->entries)) {
+ atomic_inc(&data->underrun);
+ idx_next = 0;
+ }
+
+ data->trace_idx = idx_next;
+
+ if (unlikely(idx_next != 0 && atomic_read(&data->underrun)))
+ atomic_inc(&data->underrun);
+
+ entry = data->trace + idx * TRACE_ENTRY_SIZE;
+
+ return entry;
+}
+
+static inline notrace void
+tracing_generic_entry_update(struct trace_entry *entry,
+ unsigned long flags)
+{
+ struct task_struct *tsk = current;
+ unsigned long pc;
+
+ pc = preempt_count();
+
+ entry->idx = atomic_inc_return(&tracer_counter);
+ entry->preempt_count = pc & 0xff;
+ entry->pid = tsk->pid;
+ entry->t = now(raw_smp_processor_id());
+ entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
+ ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
+ ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+ (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0);
+}
+
+notrace void
+ftrace(struct trace_array *tr, struct trace_array_cpu *data,
+ unsigned long ip, unsigned long parent_ip,
+ unsigned long flags)
+{
+ struct trace_entry *entry;
+
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_FN;
+ entry->fn.ip = ip;
+ entry->fn.parent_ip = parent_ip;
+}
+
+notrace void
+tracing_sched_switch_trace(struct trace_array *tr,
+ struct trace_array_cpu *data,
+ struct task_struct *prev, struct task_struct *next,
+ unsigned long flags)
+{
+ struct trace_entry *entry;
+
+ entry = tracing_get_trace_entry(tr, data);
+ tracing_generic_entry_update(entry, flags);
+ entry->type = TRACE_CTX;
+ entry->ctx.prev_pid = prev->pid;
+ entry->ctx.prev_prio = prev->prio;
+ entry->ctx.prev_state = prev->state;
+ entry->ctx.next_pid = next->pid;
+ entry->ctx.next_prio = next->prio;
+}
+
+enum trace_file_type {
+ TRACE_FILE_LAT_FMT = 1,
+};
+
+static struct trace_entry *
+trace_entry_idx(struct trace_array *tr, unsigned long idx, int cpu)
+{
+ struct trace_entry *array = tr->data[cpu]->trace;
+ unsigned long underrun;
+
+ if (idx >= tr->entries)
+ return NULL;
+
+ underrun = atomic_read(&tr->data[cpu]->underrun);
+ if (underrun)
+ idx = ((underrun - 1) + idx) % tr->entries;
+ else if (idx >= tr->data[cpu]->trace_idx)
+ return NULL;
+
+ return &array[idx];
+}
+
+static struct notrace trace_entry *
+find_next_entry(struct trace_iterator *iter, int *ent_cpu)
+{
+ struct trace_array *tr = iter->tr;
+ struct trace_entry *ent, *next = NULL;
+ int next_cpu = -1;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ if (!tr->data[cpu]->trace)
+ continue;
+ ent = trace_entry_idx(tr, iter->next_idx[cpu], cpu);
+ if (ent &&
+ (!next || (long)(next->idx - ent->idx) > 0)) {
+ next = ent;
+ next_cpu = cpu;
+ }
+ }
+
+ if (ent_cpu)
+ *ent_cpu = next_cpu;
+
+ return next;
+}
+
+static void *find_next_entry_inc(struct trace_iterator *iter)
+{
+ struct trace_entry *next;
+ int next_cpu = -1;
+
+ next = find_next_entry(iter, &next_cpu);
+
+ if (next) {
+ iter->next_idx[next_cpu]++;
+ iter->idx++;
+ }
+ iter->ent = next;
+ iter->cpu = next_cpu;
+
+ return next ? iter : NULL;
+}
+
+static void notrace *
+s_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct trace_iterator *iter = m->private;
+ void *ent;
+ void *last_ent = iter->ent;
+ int i = (int)*pos;
+
+ (*pos)++;
+
+ /* can't go backwards */
+ if (iter->idx > i)
+ return NULL;
+
+ if (iter->idx < 0)
+ ent = find_next_entry_inc(iter);
+ else
+ ent = iter;
+
+ while (ent && iter->idx < i)
+ ent = find_next_entry_inc(iter);
+
+ iter->pos = *pos;
+
+ if (last_ent && !ent)
+ seq_puts(m, "\n\nvim:ft=help\n");
+
+ return ent;
+}
+
+static void *s_start(struct seq_file *m, loff_t *pos)
+{
+ struct trace_iterator *iter = m->private;
+ void *p = NULL;
+ loff_t l = 0;
+ int i;
+
+ mutex_lock(&trace_types_lock);
+
+ if (!current_trace || current_trace != iter->trace)
+ return NULL;
+
+ atomic_inc(&trace_record_cmdline_disabled);
+
+ /* let the tracer grab locks here if needed */
+ if (current_trace->start)
+ current_trace->start(iter);
+
+ if (*pos != iter->pos) {
+ iter->ent = NULL;
+ iter->cpu = 0;
+ iter->idx = -1;
+
+ for (i = 0; i < NR_CPUS; i++)
+ iter->next_idx[i] = 0;
+
+ for (p = iter; p && l < *pos; p = s_next(m, p, &l))
+ ;
+
+ } else {
+ l = *pos;
+ p = s_next(m, p, &l);
+ }
+
+ return p;
+}
+
+static void s_stop(struct seq_file *m, void *p)
+{
+ struct trace_iterator *iter = m->private;
+
+ atomic_dec(&trace_record_cmdline_disabled);
+
+ /* let the tracer release locks here if needed */
+ if (current_trace && current_trace == iter->trace && iter->trace->stop)
+ iter->trace->stop(iter);
+
+ mutex_unlock(&trace_types_lock);
+}
+
+static void
+seq_print_sym_short(struct seq_file *m, const char *fmt, unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+ char str[KSYM_SYMBOL_LEN];
+
+ kallsyms_lookup(address, NULL, NULL, NULL, str);
+
+ seq_printf(m, fmt, str);
+#endif
+}
+
+static void
+seq_print_sym_offset(struct seq_file *m, const char *fmt, unsigned long address)
+{
+#ifdef CONFIG_KALLSYMS
+ char str[KSYM_SYMBOL_LEN];
+
+ sprint_symbol(str, address);
+ seq_printf(m, fmt, str);
+#endif
+}
+
+#ifndef CONFIG_64BIT
+# define IP_FMT "%08lx"
+#else
+# define IP_FMT "%016lx"
+#endif
+
+static void notrace
+seq_print_ip_sym(struct seq_file *m, unsigned long ip, unsigned long sym_flags)
+{
+ if (!ip) {
+ seq_printf(m, "0");
+ return;
+ }
+
+ if (sym_flags & TRACE_ITER_SYM_OFFSET)
+ seq_print_sym_offset(m, "%s", ip);
+ else
+ seq_print_sym_short(m, "%s", ip);
+
+ if (sym_flags & TRACE_ITER_SYM_ADDR)
+ seq_printf(m, " <" IP_FMT ">", ip);
+}
+
+static void notrace print_lat_help_header(struct seq_file *m)
+{
+ seq_puts(m, "# _------=> CPU# \n");
+ seq_puts(m, "# / _-----=> irqs-off \n");
+ seq_puts(m, "# | / _----=> need-resched \n");
+ seq_puts(m, "# || / _---=> hardirq/softirq \n");
+ seq_puts(m, "# ||| / _--=> preempt-depth \n");
+ seq_puts(m, "# |||| / \n");
+ seq_puts(m, "# ||||| delay \n");
+ seq_puts(m, "# cmd pid ||||| time | caller \n");
+ seq_puts(m, "# \\ / ||||| \\ | / \n");
+}
+
+static void notrace print_func_help_header(struct seq_file *m)
+{
+ seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n");
+ seq_puts(m, "# | | | | |\n");
+}
+
+
+static void notrace
+print_trace_header(struct seq_file *m, struct trace_iterator *iter)
+{
+ unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
+ struct trace_array *tr = iter->tr;
+ struct trace_array_cpu *data = tr->data[tr->cpu];
+ struct tracer *type = current_trace;
+ unsigned long underruns = 0;
+ unsigned long underrun;
+ unsigned long entries = 0;
+ int cpu;
+ const char *name = "preemption";
+
+ if (type)
+ name = type->name;
+
+ for_each_possible_cpu(cpu) {
+ if (tr->data[cpu]->trace) {
+ underrun = atomic_read(&tr->data[cpu]->underrun);
+ if (underrun) {
+ underruns += underrun;
+ entries += tr->entries;
+ } else
+ entries += tr->data[cpu]->trace_idx;
+ }
+ }
+
+ seq_printf(m, "%s latency trace v1.1.5 on %s\n",
+ name, UTS_RELEASE);
+ seq_puts(m, "-----------------------------------"
+ "---------------------------------\n");
+ seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
+ " (M:%s VP:%d, KP:%d, SP:%d HP:%d",
+ data->saved_latency,
+ entries,
+ (entries + underruns),
+ tr->cpu,
+#if defined(CONFIG_PREEMPT_NONE)
+ "server",
+#elif defined(CONFIG_PREEMPT_VOLUNTARY)
+ "desktop",
+#elif defined(CONFIG_PREEMPT_DESKTOP)
+ "preempt",
+#else
+ "unknown",
+#endif
+ /* These are reserved for later use */
+ 0, 0, 0, 0);
+#ifdef CONFIG_SMP
+ seq_printf(m, " #P:%d)\n", num_online_cpus());
+#else
+ seq_puts(m, ")\n");
+#endif
+ seq_puts(m, " -----------------\n");
+ seq_printf(m, " | task: %.16s-%d "
+ "(uid:%d nice:%ld policy:%ld rt_prio:%ld)\n",
+ data->comm, data->pid, data->uid, data->nice,
+ data->policy, data->rt_priority);
+ seq_puts(m, " -----------------\n");
+
+ if (data->critical_start) {
+ seq_puts(m, " => started at: ");
+ seq_print_ip_sym(m, data->critical_start, sym_flags);
+ seq_puts(m, "\n => ended at: ");
+ seq_print_ip_sym(m, data->critical_end, sym_flags);
+ seq_puts(m, "\n");
+ }
+
+ seq_puts(m, "\n");
+}
+
+unsigned long nsecs_to_usecs(unsigned long nsecs)
+{
+ return nsecs / 1000;
+}
+
+static void notrace
+lat_print_generic(struct seq_file *m, struct trace_entry *entry, int cpu)
+{
+ int hardirq, softirq;
+ char *comm;
+
+ comm = trace_find_cmdline(entry->pid);
+
+ seq_printf(m, "%8.8s-%-5d ", comm, entry->pid);
+ seq_printf(m, "%d", cpu);
+ seq_printf(m, "%c%c",
+ (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.',
+ ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.'));
+
+ hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
+ softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
+ if (hardirq && softirq)
+ seq_putc(m, 'H');
+ else {
+ if (hardirq)
+ seq_putc(m, 'h');
+ else {
+ if (softirq)
+ seq_putc(m, 's');
+ else
+ seq_putc(m, '.');
+ }
+ }
+
+ if (entry->preempt_count)
+ seq_printf(m, "%x", entry->preempt_count);
+ else
+ seq_puts(m, ".");
+}
+
+unsigned long preempt_mark_thresh = 100;
+
+static void notrace
+lat_print_timestamp(struct seq_file *m, unsigned long long abs_usecs,
+ unsigned long rel_usecs)
+{
+ seq_printf(m, " %4lldus", abs_usecs);
+ if (rel_usecs > preempt_mark_thresh)
+ seq_puts(m, "!: ");
+ else if (rel_usecs > 1)
+ seq_puts(m, "+: ");
+ else
+ seq_puts(m, " : ");
+}
+
+static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
+
+static void notrace
+print_lat_fmt(struct seq_file *m, struct trace_iterator *iter,
+ unsigned int trace_idx, int cpu)
+{
+ unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
+ struct trace_entry *next_entry = find_next_entry(iter, NULL);
+ unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE);
+ struct trace_entry *entry = iter->ent;
+ unsigned long abs_usecs;
+ unsigned long rel_usecs;
+ char *comm;
+ int S;
+
+ if (!next_entry)
+ next_entry = entry;
+ rel_usecs = ns2usecs(next_entry->t - entry->t);
+ abs_usecs = ns2usecs(entry->t - iter->tr->time_start);
+
+ if (verbose) {
+ comm = trace_find_cmdline(entry->pid);
+ seq_printf(m, "%16s %5d %d %d %08x %08x [%08lx]"
+ " %ld.%03ldms (+%ld.%03ldms): ",
+ comm,
+ entry->pid, cpu, entry->flags,
+ entry->preempt_count, trace_idx,
+ ns2usecs(entry->t),
+ abs_usecs/1000,
+ abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000);
+ } else {
+ lat_print_generic(m, entry, cpu);
+ lat_print_timestamp(m, abs_usecs, rel_usecs);
+ }
+ switch (entry->type) {
+ case TRACE_FN:
+ seq_print_ip_sym(m, entry->fn.ip, sym_flags);
+ seq_puts(m, " (");
+ seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
+ seq_puts(m, ")\n");
+ break;
+ case TRACE_CTX:
+ S = entry->ctx.prev_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.prev_state] : 'X';
+ comm = trace_find_cmdline(entry->ctx.next_pid);
+ seq_printf(m, " %d:%d:%c --> %d:%d %s\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio,
+ comm);
+ break;
+ }
+}
+
+static void notrace
+print_trace_fmt(struct seq_file *m, struct trace_iterator *iter)
+{
+ unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
+ struct trace_entry *entry = iter->ent;
+ unsigned long usec_rem;
+ unsigned long long t;
+ unsigned long secs;
+ char *comm;
+ int S;
+
+ comm = trace_find_cmdline(iter->ent->pid);
+
+ t = ns2usecs(entry->t);
+ usec_rem = do_div(t, 1000000ULL);
+ secs = (unsigned long)t;
+
+ seq_printf(m, "%16s-%-5d ", comm, entry->pid);
+ seq_printf(m, "[%02d] ", iter->cpu);
+ seq_printf(m, "%5lu.%06lu: ", secs, usec_rem);
+
+ switch (entry->type) {
+ case TRACE_FN:
+ seq_print_ip_sym(m, entry->fn.ip, sym_flags);
+ if ((sym_flags & TRACE_ITER_PRINT_PARENT) &&
+ entry->fn.parent_ip) {
+ seq_printf(m, " <-");
+ seq_print_ip_sym(m, entry->fn.parent_ip, sym_flags);
+ }
+ break;
+ case TRACE_CTX:
+ S = entry->ctx.prev_state < sizeof(state_to_char) ?
+ state_to_char[entry->ctx.prev_state] : 'X';
+ seq_printf(m, " %d:%d:%c ==> %d:%d\n",
+ entry->ctx.prev_pid,
+ entry->ctx.prev_prio,
+ S,
+ entry->ctx.next_pid,
+ entry->ctx.next_prio);
+ break;
+ }
+ seq_printf(m, "\n");
+}
+
+static int trace_empty(struct trace_iterator *iter)
+{
+ struct trace_array_cpu *data;
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ data = iter->tr->data[cpu];
+
+ if (data->trace &&
+ (data->trace_idx ||
+ atomic_read(&data->underrun)))
+ return 0;
+ }
+ return 1;
+}
+
+static int s_show(struct seq_file *m, void *v)
+{
+ struct trace_iterator *iter = v;
+
+ if (iter->ent == NULL) {
+ if (iter->tr) {
+ seq_printf(m, "# tracer: %s\n", iter->trace->name);
+ seq_puts(m, "#\n");
+ }
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+ /* print nothing if the buffers are empty */
+ if (trace_empty(iter))
+ return 0;
+ print_trace_header(m, iter);
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_lat_help_header(m);
+ } else {
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_func_help_header(m);
+ }
+ } else {
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ print_lat_fmt(m, iter, iter->idx, iter->cpu);
+ else
+ print_trace_fmt(m, iter);
+ }
+
+ return 0;
+}
+
+static struct seq_operations tracer_seq_ops = {
+ .start = s_start,
+ .next = s_next,
+ .stop = s_stop,
+ .show = s_show,
+};
+
+static struct trace_iterator notrace *
+__tracing_open(struct inode *inode, struct file *file, int *ret)
+{
+ struct trace_iterator *iter;
+
+ iter = kzalloc(sizeof(*iter), GFP_KERNEL);
+ if (!iter) {
+ *ret = -ENOMEM;
+ goto out;
+ }
+
+ mutex_lock(&trace_types_lock);
+ if (current_trace && current_trace->print_max)
+ iter->tr = &max_tr;
+ else
+ iter->tr = inode->i_private;
+ iter->trace = current_trace;
+ iter->pos = -1;
+
+ /* TODO stop tracer */
+ *ret = seq_open(file, &tracer_seq_ops);
+ if (!*ret) {
+ struct seq_file *m = file->private_data;
+ m->private = iter;
+
+ /* stop the trace while dumping */
+ if (iter->tr->ctrl)
+ tracer_enabled = 0;
+
+ if (iter->trace && iter->trace->open)
+ iter->trace->open(iter);
+ } else {
+ kfree(iter);
+ iter = NULL;
+ }
+ mutex_unlock(&trace_types_lock);
+
+ out:
+ return iter;
+}
+
+int tracing_open_generic(struct inode *inode, struct file *filp)
+{
+ filp->private_data = inode->i_private;
+ return 0;
+}
+
+int tracing_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *m = (struct seq_file *)file->private_data;
+ struct trace_iterator *iter = m->private;
+
+ mutex_lock(&trace_types_lock);
+ if (iter->trace && iter->trace->close)
+ iter->trace->close(iter);
+
+ /* reenable tracing if it was previously enabled */
+ if (iter->tr->ctrl)
+ tracer_enabled = 1;
+ mutex_unlock(&trace_types_lock);
+
+ seq_release(inode, file);
+ kfree(iter);
+ return 0;
+}
+
+static int tracing_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ __tracing_open(inode, file, &ret);
+
+ return ret;
+}
+
+static int tracing_lt_open(struct inode *inode, struct file *file)
+{
+ struct trace_iterator *iter;
+ int ret;
+
+ iter = __tracing_open(inode, file, &ret);
+
+ if (!ret)
+ iter->iter_flags |= TRACE_FILE_LAT_FMT;
+
+ return ret;
+}
+
+
+static void notrace *
+t_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct tracer *t = m->private;
+
+ (*pos)++;
+
+ if (t)
+ t = t->next;
+
+ m->private = t;
+
+ return t;
+}
+
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
+ struct tracer *t = m->private;
+ loff_t l = 0;
+
+ mutex_lock(&trace_types_lock);
+ for (; t && l < *pos; t = t_next(m, t, &l))
+ ;
+
+ return t;
+}
+
+static void t_stop(struct seq_file *m, void *p)
+{
+ mutex_unlock(&trace_types_lock);
+}
+
+static int t_show(struct seq_file *m, void *v)
+{
+ struct tracer *t = v;
+
+ if (!t)
+ return 0;
+
+ seq_printf(m, "%s", t->name);
+ if (t->next)
+ seq_putc(m, ' ');
+ else
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static struct seq_operations show_traces_seq_ops = {
+ .start = t_start,
+ .next = t_next,
+ .stop = t_stop,
+ .show = t_show,
+};
+
+static int show_traces_open(struct inode *inode, struct file *file)
+{
+ int ret;
+
+ ret = seq_open(file, &show_traces_seq_ops);
+ if (!ret) {
+ struct seq_file *m = file->private_data;
+ m->private = trace_types;
+ }
+
+ return ret;
+}
+
+static struct file_operations tracing_fops = {
+ .open = tracing_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_release,
+};
+
+static struct file_operations tracing_lt_fops = {
+ .open = tracing_lt_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = tracing_release,
+};
+
+static struct file_operations show_traces_fops = {
+ .open = show_traces_open,
+ .read = seq_read,
+ .release = seq_release,
+};
+
+static ssize_t
+tracing_iter_ctrl_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char *buf;
+ int r = 0;
+ int len = 0;
+ int i;
+
+ /* calulate max size */
+ for (i = 0; trace_options[i]; i++) {
+ len += strlen(trace_options[i]);
+ len += 3; /* "no" and space */
+ }
+
+ /* +2 for \n and \0 */
+ buf = kmalloc(len + 2, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ for (i = 0; trace_options[i]; i++) {
+ if (trace_flags & (1 << i))
+ r += sprintf(buf + r, "%s ", trace_options[i]);
+ else
+ r += sprintf(buf + r, "no%s ", trace_options[i]);
+ }
+
+ r += sprintf(buf + r, "\n");
+ WARN_ON(r >= len + 2);
+
+ r = simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, r);
+
+ kfree(buf);
+
+ return r;
+}
+
+static ssize_t
+tracing_iter_ctrl_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[64];
+ char *cmp = buf;
+ int neg = 0;
+ int i;
+
+ if (cnt > 63)
+ cnt = 63;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ if (strncmp(buf, "no", 2) == 0) {
+ neg = 1;
+ cmp += 2;
+ }
+
+ for (i = 0; trace_options[i]; i++) {
+ int len = strlen(trace_options[i]);
+
+ if (strncmp(cmp, trace_options[i], len) == 0) {
+ if (neg)
+ trace_flags &= ~(1 << i);
+ else
+ trace_flags |= (1 << i);
+ break;
+ }
+ }
+
+ filp->f_pos += cnt;
+
+ return cnt;
+}
+
+static struct file_operations tracing_iter_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_iter_ctrl_read,
+ .write = tracing_iter_ctrl_write,
+};
+
+static ssize_t
+tracing_ctrl_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = sprintf(buf, "%ld\n", tr->ctrl);
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, r);
+}
+
+static ssize_t
+tracing_ctrl_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = filp->private_data;
+ long val;
+ char buf[64];
+
+ if (cnt > 63)
+ cnt = 63;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ val = simple_strtoul(buf, NULL, 10);
+
+ val = !!val;
+
+ mutex_lock(&trace_types_lock);
+ if (tr->ctrl ^ val) {
+ if (val)
+ tracer_enabled = 1;
+ else
+ tracer_enabled = 0;
+
+ tr->ctrl = val;
+
+ if (current_trace && current_trace->ctrl_update)
+ current_trace->ctrl_update(tr);
+ }
+ mutex_unlock(&trace_types_lock);
+
+ filp->f_pos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+tracing_set_trace_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[max_tracer_type_len+2];
+ int r;
+
+ mutex_lock(&trace_types_lock);
+ if (current_trace)
+ r = sprintf(buf, "%s\n", current_trace->name);
+ else
+ r = sprintf(buf, "\n");
+ mutex_unlock(&trace_types_lock);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, r);
+}
+
+static ssize_t
+tracing_set_trace_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ struct trace_array *tr = &global_trace;
+ struct tracer *t;
+ char buf[max_tracer_type_len+1];
+ int i;
+
+ if (cnt > max_tracer_type_len)
+ cnt = max_tracer_type_len;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ /* strip ending whitespace. */
+ for (i = cnt - 1; i > 0 && isspace(buf[i]); i--)
+ buf[i] = 0;
+
+ mutex_lock(&trace_types_lock);
+ for (t = trace_types; t; t = t->next) {
+ if (strcmp(t->name, buf) == 0)
+ break;
+ }
+ if (!t || t == current_trace)
+ goto out;
+
+ if (current_trace && current_trace->reset)
+ current_trace->reset(tr);
+
+ current_trace = t;
+ if (t->init)
+ t->init(tr);
+
+ out:
+ mutex_unlock(&trace_types_lock);
+
+ filp->f_pos += cnt;
+
+ return cnt;
+}
+
+static ssize_t
+tracing_max_lat_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long *ptr = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = snprintf(buf, 64, "%ld\n",
+ *ptr == (unsigned long)-1 ? -1 : nsecs_to_usecs(*ptr));
+ if (r > 64)
+ r = 64;
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, r);
+}
+
+static ssize_t
+tracing_max_lat_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ long *ptr = filp->private_data;
+ long val;
+ char buf[64];
+
+ if (cnt > 63)
+ cnt = 63;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt] = 0;
+
+ val = simple_strtoul(buf, NULL, 10);
+
+ *ptr = val * 1000;
+
+ return cnt;
+}
+
+static struct file_operations tracing_max_lat_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_max_lat_read,
+ .write = tracing_max_lat_write,
+};
+
+static struct file_operations tracing_ctrl_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_ctrl_read,
+ .write = tracing_ctrl_write,
+};
+
+static struct file_operations set_tracer_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_set_trace_read,
+ .write = tracing_set_trace_write,
+};
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+
+static ssize_t
+tracing_read_long(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ unsigned long *p = filp->private_data;
+ char buf[64];
+ int r;
+
+ r = sprintf(buf, "%ld\n", *p);
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ buf, r);
+}
+
+static struct file_operations tracing_read_long_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_read_long,
+};
+#endif
+
+static struct dentry *d_tracer;
+
+struct dentry *tracing_init_dentry(void)
+{
+ static int once;
+
+ if (d_tracer)
+ return d_tracer;
+
+ d_tracer = debugfs_create_dir("tracing", NULL);
+
+ if (!d_tracer && !once) {
+ once = 1;
+ pr_warning("Could not create debugfs directory 'tracing'\n");
+ return NULL;
+ }
+
+ return d_tracer;
+}
+
+static __init void tracer_init_debugfs(void)
+{
+ struct dentry *d_tracer;
+ struct dentry *entry;
+
+ d_tracer = tracing_init_dentry();
+
+ entry = debugfs_create_file("tracing_enabled", 0644, d_tracer,
+ &global_trace, &tracing_ctrl_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'tracing_enabled' entry\n");
+
+ entry = debugfs_create_file("iter_ctrl", 0644, d_tracer,
+ NULL, &tracing_iter_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'iter_ctrl' entry\n");
+
+ entry = debugfs_create_file("latency_trace", 0444, d_tracer,
+ &global_trace, &tracing_lt_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'latency_trace' entry\n");
+
+ entry = debugfs_create_file("trace", 0444, d_tracer,
+ &global_trace, &tracing_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'trace' entry\n");
+
+ entry = debugfs_create_file("available_tracers", 0444, d_tracer,
+ &global_trace, &show_traces_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'trace' entry\n");
+
+ entry = debugfs_create_file("current_tracer", 0444, d_tracer,
+ &global_trace, &set_tracer_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs 'trace' entry\n");
+
+ entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer,
+ &tracing_max_latency,
+ &tracing_max_lat_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'tracing_max_latency' entry\n");
+
+ entry = debugfs_create_file("tracing_thresh", 0644, d_tracer,
+ &tracing_thresh, &tracing_max_lat_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'tracing_threash' entry\n");
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+ entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer,
+ &ftrace_update_tot_cnt,
+ &tracing_read_long_fops);
+ if (!entry)
+ pr_warning("Could not create debugfs "
+ "'dyn_ftrace_total_info' entry\n");
+#endif
+}
+
+/* dummy trace to disable tracing */
+static struct tracer no_tracer __read_mostly =
+{
+ .name = "none",
+};
+
+static inline notrace int page_order(const unsigned long size)
+{
+ const unsigned long nr_pages = DIV_ROUND_UP(size, PAGE_SIZE);
+ return ilog2(roundup_pow_of_two(nr_pages));
+}
+
+__init static int tracer_alloc_buffers(void)
+{
+ const int order = page_order(trace_nr_entries * TRACE_ENTRY_SIZE);
+ const unsigned long size = (1UL << order) << PAGE_SHIFT;
+ struct trace_entry *array;
+ int i;
+
+ for_each_possible_cpu(i) {
+ global_trace.data[i] = &per_cpu(global_trace_cpu, i);
+ max_tr.data[i] = &per_cpu(max_data, i);
+
+ array = (struct trace_entry *)
+ __get_free_pages(GFP_KERNEL, order);
+ if (array == NULL) {
+ printk(KERN_ERR "tracer: failed to allocate"
+ " %ld bytes for trace buffer!\n", size);
+ goto free_buffers;
+ }
+ global_trace.data[i]->trace = array;
+
+/* Only allocate if we are actually using the max trace */
+#ifdef CONFIG_TRACER_MAX_TRACE
+ array = (struct trace_entry *)
+ __get_free_pages(GFP_KERNEL, order);
+ if (array == NULL) {
+ printk(KERN_ERR "wakeup tracer: failed to allocate"
+ " %ld bytes for trace buffer!\n", size);
+ goto free_buffers;
+ }
+ max_tr.data[i]->trace = array;
+#endif
+ }
+
+ /*
+ * Since we allocate by orders of pages, we may be able to
+ * round up a bit.
+ */
+ global_trace.entries = size / TRACE_ENTRY_SIZE;
+ max_tr.entries = global_trace.entries;
+
+ pr_info("tracer: %ld bytes allocated for %ld",
+ size, trace_nr_entries);
+ pr_info(" entries of %ld bytes\n", (long)TRACE_ENTRY_SIZE);
+ pr_info(" actual entries %ld\n", global_trace.entries);
+
+ tracer_init_debugfs();
+
+ trace_init_cmdlines();
+
+ register_tracer(&no_tracer);
+ current_trace = &no_tracer;
+
+ return 0;
+
+ free_buffers:
+ for (i-- ; i >= 0; i--) {
+ struct trace_array_cpu *data = global_trace.data[i];
+
+ if (data && data->trace) {
+ free_pages((unsigned long)data->trace, order);
+ data->trace = NULL;
+ }
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ data = max_tr.data[i];
+ if (data && data->trace) {
+ free_pages((unsigned long)data->trace, order);
+ data->trace = NULL;
+ }
+#endif
+ }
+ return -ENOMEM;
+}
+
+device_initcall(tracer_alloc_buffers);
projects / linux-2.6-omap-h63xx.git / commitdiff