unsigned long __read_mostly tracing_max_latency;
unsigned long __read_mostly tracing_thresh;
+/*
+ * On boot up, the ring buffer is set to the minimum size, so that
+ * we do not waste memory on systems that are not using tracing.
+ */
+static int ring_buffer_expanded;
+
/*
* We need to change this state when a selftest is running.
* A selftest will lurk into the ring-buffer to count the
{
strncpy(bootup_tracer_buf, str, BOOTUP_TRACER_SIZE);
default_bootup_tracer = bootup_tracer_buf;
+ /* We are using ftrace early, expand it */
+ ring_buffer_expanded = 1;
return 1;
}
__setup("ftrace=", set_ftrace);
entry->preempt_count = pc & 0xff;
entry->pid = (tsk) ? tsk->pid : 0;
- entry->tgid = (tsk) ? tsk->tgid : 0;
+ entry->tgid = (tsk) ? tsk->tgid : 0;
entry->flags =
#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
(irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) |
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+/**
+ * trace_vprintk - write binary msg to tracing buffer
+ *
+ */
+int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
+{
+ static raw_spinlock_t trace_buf_lock =
+ (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;
+ static u32 trace_buf[TRACE_BUF_SIZE];
+
+ struct ring_buffer_event *event;
+ struct trace_array *tr = &global_trace;
+ struct trace_array_cpu *data;
+ struct print_entry *entry;
+ unsigned long flags;
+ int resched;
+ int cpu, len = 0, size, pc;
+
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
+
+ /* Don't pollute graph traces with trace_vprintk internals */
+ pause_graph_tracing();
+
+ pc = preempt_count();
+ resched = ftrace_preempt_disable();
+ cpu = raw_smp_processor_id();
+ data = tr->data[cpu];
+
+ if (unlikely(atomic_read(&data->disabled)))
+ goto out;
+
+ /* Lockdep uses trace_printk for lock tracing */
+ local_irq_save(flags);
+ __raw_spin_lock(&trace_buf_lock);
+ len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args);
+
+ if (len > TRACE_BUF_SIZE || len < 0)
+ goto out_unlock;
+
+ size = sizeof(*entry) + sizeof(u32) * len;
+ event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, flags, pc);
+ if (!event)
+ goto out_unlock;
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->depth = depth;
+ entry->fmt = fmt;
+
+ memcpy(entry->buf, trace_buf, sizeof(u32) * len);
+ ring_buffer_unlock_commit(tr->buffer, event);
+
+out_unlock:
+ __raw_spin_unlock(&trace_buf_lock);
+ local_irq_restore(flags);
+
+out:
+ ftrace_preempt_enable(resched);
+ unpause_graph_tracing();
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(trace_vprintk);
+
enum trace_file_type {
TRACE_FILE_LAT_FMT = 1,
TRACE_FILE_ANNOTATE = 2,
total = entries +
ring_buffer_overruns(iter->tr->buffer);
- seq_printf(m, "%s latency trace v1.1.5 on %s\n",
+ seq_printf(m, "# %s latency trace v1.1.5 on %s\n",
name, UTS_RELEASE);
- seq_puts(m, "-----------------------------------"
+ seq_puts(m, "# -----------------------------------"
"---------------------------------\n");
- seq_printf(m, " latency: %lu us, #%lu/%lu, CPU#%d |"
+ seq_printf(m, "# latency: %lu us, #%lu/%lu, CPU#%d |"
" (M:%s VP:%d, KP:%d, SP:%d HP:%d",
nsecs_to_usecs(data->saved_latency),
entries,
#else
seq_puts(m, ")\n");
#endif
- seq_puts(m, " -----------------\n");
- seq_printf(m, " | task: %.16s-%d "
+ 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");
+ seq_puts(m, "# -----------------\n");
if (data->critical_start) {
- seq_puts(m, " => started at: ");
+ seq_puts(m, "# => started at: ");
seq_print_ip_sym(&iter->seq, data->critical_start, sym_flags);
trace_print_seq(m, &iter->seq);
- seq_puts(m, "\n => ended at: ");
+ seq_puts(m, "\n# => ended at: ");
seq_print_ip_sym(&iter->seq, data->critical_end, sym_flags);
trace_print_seq(m, &iter->seq);
- seq_puts(m, "\n");
+ seq_puts(m, "#\n");
}
- seq_puts(m, "\n");
+ seq_puts(m, "#\n");
}
static void test_cpu_buff_start(struct trace_iterator *iter)
trace_assign_type(field, entry);
- ret = trace_seq_printf(s, "%s", field->buf);
+ ret = trace_seq_bprintf(s, field->fmt, field->buf);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
{
int cpu;
+ /* If we are looking at one CPU buffer, only check that one */
+ if (iter->cpu_file != TRACE_PIPE_ALL_CPU) {
+ cpu = iter->cpu_file;
+ if (iter->buffer_iter[cpu]) {
+ if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
+ return 0;
+ } else {
+ if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu))
+ return 0;
+ }
+ return 1;
+ }
+
for_each_tracing_cpu(cpu) {
if (iter->buffer_iter[cpu]) {
if (!ring_buffer_iter_empty(iter->buffer_iter[cpu]))
iter->buffer_iter[cpu] =
ring_buffer_read_start(iter->tr->buffer, cpu);
-
- if (!iter->buffer_iter[cpu])
- goto fail_buffer;
}
} else {
cpu = iter->cpu_file;
iter->buffer_iter[cpu] =
ring_buffer_read_start(iter->tr->buffer, cpu);
-
- if (!iter->buffer_iter[cpu])
- goto fail;
}
/* TODO stop tracer */
return ret;
}
-static struct file_operations tracing_fops = {
+static const struct file_operations tracing_fops = {
.open = tracing_open,
.read = seq_read,
.llseek = seq_lseek,
.release = tracing_release,
};
-static struct file_operations show_traces_fops = {
+static const struct file_operations show_traces_fops = {
.open = show_traces_open,
.read = seq_read,
.release = seq_release,
return err;
}
-static struct file_operations tracing_cpumask_fops = {
+static const struct file_operations tracing_cpumask_fops = {
.open = tracing_open_generic,
.read = tracing_cpumask_read,
.write = tracing_cpumask_write,
return cnt;
}
-static struct file_operations tracing_iter_fops = {
+static const struct file_operations tracing_iter_fops = {
.open = tracing_open_generic,
.read = tracing_trace_options_read,
.write = tracing_trace_options_write,
readme_msg, strlen(readme_msg));
}
-static struct file_operations tracing_readme_fops = {
+static const struct file_operations tracing_readme_fops = {
.open = tracing_open_generic,
.read = tracing_readme_read,
};
return t->init(tr);
}
+static int tracing_resize_ring_buffer(unsigned long size)
+{
+ int ret;
+
+ /*
+ * If kernel or user changes the size of the ring buffer
+ * we use the size that was given, and we can forget about
+ * expanding it later.
+ */
+ ring_buffer_expanded = 1;
+
+ ret = ring_buffer_resize(global_trace.buffer, size);
+ if (ret < 0)
+ return ret;
+
+ ret = ring_buffer_resize(max_tr.buffer, size);
+ if (ret < 0) {
+ int r;
+
+ r = ring_buffer_resize(global_trace.buffer,
+ global_trace.entries);
+ if (r < 0) {
+ /*
+ * AARGH! We are left with different
+ * size max buffer!!!!
+ * The max buffer is our "snapshot" buffer.
+ * When a tracer needs a snapshot (one of the
+ * latency tracers), it swaps the max buffer
+ * with the saved snap shot. We succeeded to
+ * update the size of the main buffer, but failed to
+ * update the size of the max buffer. But when we tried
+ * to reset the main buffer to the original size, we
+ * failed there too. This is very unlikely to
+ * happen, but if it does, warn and kill all
+ * tracing.
+ */
+ WARN_ON(1);
+ tracing_disabled = 1;
+ }
+ return ret;
+ }
+
+ global_trace.entries = size;
+
+ return ret;
+}
+
+/**
+ * tracing_update_buffers - used by tracing facility to expand ring buffers
+ *
+ * To save on memory when the tracing is never used on a system with it
+ * configured in. The ring buffers are set to a minimum size. But once
+ * a user starts to use the tracing facility, then they need to grow
+ * to their default size.
+ *
+ * This function is to be called when a tracer is about to be used.
+ */
+int tracing_update_buffers(void)
+{
+ int ret = 0;
+
+ mutex_lock(&trace_types_lock);
+ if (!ring_buffer_expanded)
+ ret = tracing_resize_ring_buffer(trace_buf_size);
+ mutex_unlock(&trace_types_lock);
+
+ return ret;
+}
+
struct trace_option_dentry;
static struct trace_option_dentry *
int ret = 0;
mutex_lock(&trace_types_lock);
+
+ if (!ring_buffer_expanded) {
+ ret = tracing_resize_ring_buffer(trace_buf_size);
+ if (ret < 0)
+ return ret;
+ ret = 0;
+ }
+
for (t = trace_types; t; t = t->next) {
if (strcmp(t->name, buf) == 0)
break;
val <<= 10;
if (val != global_trace.entries) {
- ret = ring_buffer_resize(global_trace.buffer, val);
+ ret = tracing_resize_ring_buffer(val);
if (ret < 0) {
cnt = ret;
goto out;
}
-
- ret = ring_buffer_resize(max_tr.buffer, val);
- if (ret < 0) {
- int r;
- cnt = ret;
- r = ring_buffer_resize(global_trace.buffer,
- global_trace.entries);
- if (r < 0) {
- /* AARGH! We are left with different
- * size max buffer!!!! */
- WARN_ON(1);
- tracing_disabled = 1;
- }
- goto out;
- }
-
- global_trace.entries = val;
}
filp->f_pos += cnt;
return cnt;
}
-static struct file_operations tracing_max_lat_fops = {
+static const 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 = {
+static const 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 = {
+static const struct file_operations set_tracer_fops = {
.open = tracing_open_generic,
.read = tracing_set_trace_read,
.write = tracing_set_trace_write,
};
-static struct file_operations tracing_pipe_fops = {
+static const struct file_operations tracing_pipe_fops = {
.open = tracing_open_pipe,
.poll = tracing_poll_pipe,
.read = tracing_read_pipe,
.release = tracing_release_pipe,
};
-static struct file_operations tracing_entries_fops = {
+static const struct file_operations tracing_entries_fops = {
.open = tracing_open_generic,
.read = tracing_entries_read,
.write = tracing_entries_write,
};
-static struct file_operations tracing_mark_fops = {
+static const struct file_operations tracing_mark_fops = {
.open = tracing_open_generic,
.write = tracing_mark_write,
};
return r;
}
-static struct file_operations tracing_dyn_info_fops = {
+static const struct file_operations tracing_dyn_info_fops = {
.open = tracing_open_generic,
.read = tracing_read_dyn_info,
};
return 0;
}
-int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
-{
- static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
- static char trace_buf[TRACE_BUF_SIZE];
-
- struct ring_buffer_event *event;
- struct trace_array *tr = &global_trace;
- struct trace_array_cpu *data;
- int cpu, len = 0, size, pc;
- struct print_entry *entry;
- unsigned long irq_flags;
-
- if (tracing_disabled || tracing_selftest_running)
- return 0;
-
- pc = preempt_count();
- preempt_disable_notrace();
- cpu = raw_smp_processor_id();
- data = tr->data[cpu];
-
- if (unlikely(atomic_read(&data->disabled)))
- goto out;
-
- pause_graph_tracing();
- raw_local_irq_save(irq_flags);
- __raw_spin_lock(&trace_buf_lock);
- len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
-
- len = min(len, TRACE_BUF_SIZE-1);
- trace_buf[len] = 0;
-
- size = sizeof(*entry) + len + 1;
- event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, irq_flags, pc);
- if (!event)
- goto out_unlock;
- entry = ring_buffer_event_data(event);
- entry->ip = ip;
- entry->depth = depth;
-
- memcpy(&entry->buf, trace_buf, len);
- entry->buf[len] = 0;
- ring_buffer_unlock_commit(tr->buffer, event);
-
- out_unlock:
- __raw_spin_unlock(&trace_buf_lock);
- raw_local_irq_restore(irq_flags);
- unpause_graph_tracing();
- out:
- preempt_enable_notrace();
-
- return len;
-}
-EXPORT_SYMBOL_GPL(trace_vprintk);
-
-int __trace_printk(unsigned long ip, const char *fmt, ...)
-{
- int ret;
- va_list ap;
-
- if (!(trace_flags & TRACE_ITER_PRINTK))
- return 0;
-
- va_start(ap, fmt);
- ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
- va_end(ap);
- return ret;
-}
-EXPORT_SYMBOL_GPL(__trace_printk);
-
-int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap)
-{
- if (!(trace_flags & TRACE_ITER_PRINTK))
- return 0;
-
- return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);
-}
-EXPORT_SYMBOL_GPL(__ftrace_vprintk);
-
static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{
__init static int tracer_alloc_buffers(void)
{
struct trace_array_cpu *data;
+ int ring_buf_size;
int i;
int ret = -ENOMEM;
if (!alloc_cpumask_var(&tracing_reader_cpumask, GFP_KERNEL))
goto out_free_tracing_cpumask;
+ /* To save memory, keep the ring buffer size to its minimum */
+ if (ring_buffer_expanded)
+ ring_buf_size = trace_buf_size;
+ else
+ ring_buf_size = 1;
+
cpumask_copy(tracing_buffer_mask, cpu_possible_mask);
cpumask_copy(tracing_cpumask, cpu_all_mask);
cpumask_clear(tracing_reader_cpumask);
/* TODO: make the number of buffers hot pluggable with CPUS */
- global_trace.buffer = ring_buffer_alloc(trace_buf_size,
+ global_trace.buffer = ring_buffer_alloc(ring_buf_size,
TRACE_BUFFER_FLAGS);
if (!global_trace.buffer) {
printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
#ifdef CONFIG_TRACER_MAX_TRACE
- max_tr.buffer = ring_buffer_alloc(trace_buf_size,
+ max_tr.buffer = ring_buffer_alloc(ring_buf_size,
TRACE_BUFFER_FLAGS);
if (!max_tr.buffer) {
printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n");
projects / mirror_ubuntu-zesty-kernel.git / blobdiff