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-rw-r--r--kernel/trace/trace.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index f5427e0fc982..74df029056b0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3595,6 +3595,45 @@ static const struct file_operations tracing_buffers_fops = {
.llseek = no_llseek,
};
+static ssize_t
+tracing_stats_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos)
+{
+ unsigned long cpu = (unsigned long)filp->private_data;
+ struct trace_array *tr = &global_trace;
+ struct trace_seq *s;
+ unsigned long cnt;
+
+ s = kmalloc(sizeof(*s), GFP_ATOMIC);
+ if (!s)
+ return ENOMEM;
+
+ trace_seq_init(s);
+
+ cnt = ring_buffer_entries_cpu(tr->buffer, cpu);
+ trace_seq_printf(s, "entries: %ld\n", cnt);
+
+ cnt = ring_buffer_overrun_cpu(tr->buffer, cpu);
+ trace_seq_printf(s, "overrun: %ld\n", cnt);
+
+ cnt = ring_buffer_commit_overrun_cpu(tr->buffer, cpu);
+ trace_seq_printf(s, "commit overrun: %ld\n", cnt);
+
+ cnt = ring_buffer_nmi_dropped_cpu(tr->buffer, cpu);
+ trace_seq_printf(s, "nmi dropped: %ld\n", cnt);
+
+ count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len);
+
+ kfree(s);
+
+ return count;
+}
+
+static const struct file_operations tracing_stats_fops = {
+ .open = tracing_open_generic,
+ .read = tracing_stats_read,
+};
+
#ifdef CONFIG_DYNAMIC_FTRACE
int __weak ftrace_arch_read_dyn_info(char *buf, int size)
@@ -3708,6 +3747,9 @@ static void tracing_init_debugfs_percpu(long cpu)
trace_create_file("trace_pipe_raw", 0444, d_cpu,
(void *) cpu, &tracing_buffers_fops);
+
+ trace_create_file("stats", 0444, d_cpu,
+ (void *) cpu, &tracing_stats_fops);
}
#ifdef CONFIG_FTRACE_SELFTEST