Commit f81ab074 authored by Vaibhav Nagarnaik's avatar Vaibhav Nagarnaik Committed by Steven Rostedt
Browse files

trace: Add a new readonly entry to report total buffer size 



The current file "buffer_size_kb" reports the size of per-cpu buffer and
not the overall memory allocated which could be misleading. A new file
"buffer_total_size_kb" adds up all the enabled CPU buffer sizes and
reports it. This is only a readonly entry.

Signed-off-by: default avatarVaibhav Nagarnaik <vnagarnaik@google.com>
Cc: Michael Rubin <mrubin@google.com>
Cc: David Sharp <dhsharp@google.com>
Link: http://lkml.kernel.org/r/1313531179-9323-2-git-send-email-vnagarnaik@google.com


Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 86b6ef21

kernel/trace/trace.c

+33 −0
Original line number Diff line number Diff line
@@ -3568,6 +3568,30 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, 
	return cnt;

}



static ssize_t

tracing_total_entries_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, cpu;

	unsigned long size = 0, expanded_size = 0;



	mutex_lock(&trace_types_lock);

	for_each_tracing_cpu(cpu) {

		size += tr->entries >> 10;

		if (!ring_buffer_expanded)

			expanded_size += trace_buf_size >> 10;

	}

	if (ring_buffer_expanded)

		r = sprintf(buf, "%lu\n", size);

	else

		r = sprintf(buf, "%lu (expanded: %lu)\n", size, expanded_size);

	mutex_unlock(&trace_types_lock);



	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);

}



static ssize_t

tracing_free_buffer_write(struct file *filp, const char __user *ubuf,

			  size_t cnt, loff_t *ppos)
@@ -3739,6 +3763,12 @@ static const struct file_operations tracing_entries_fops = { 
	.llseek		= generic_file_llseek,

};



static const struct file_operations tracing_total_entries_fops = {

	.open		= tracing_open_generic,

	.read		= tracing_total_entries_read,

	.llseek		= generic_file_llseek,

};



static const struct file_operations tracing_free_buffer_fops = {

	.write		= tracing_free_buffer_write,

	.release	= tracing_free_buffer_release,
@@ -4450,6 +4480,9 @@ static __init int tracer_init_debugfs(void) 
	trace_create_file("buffer_size_kb", 0644, d_tracer,

			&global_trace, &tracing_entries_fops);



	trace_create_file("buffer_total_size_kb", 0444, d_tracer,

			&global_trace, &tracing_total_entries_fops);



	trace_create_file("free_buffer", 0644, d_tracer,

			&global_trace, &tracing_free_buffer_fops);

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