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authorVaibhav Nagarnaik <vnagarnaik@google.com>2011-08-16 14:46:15 -0700
committerSteven Rostedt <rostedt@goodmis.org>2011-08-30 12:27:44 -0400
commitf81ab074c30234b07c8309c542cafd07bed721f7 (patch)
tree58ec049e4f63d0f8a0b696195cf77da2b6d04b01 /kernel/trace/trace.c
parent86b6ef21b80ac6565d172cdab4384404de007eea (diff)
downloadlwn-f81ab074c30234b07c8309c542cafd07bed721f7.tar.gz
lwn-f81ab074c30234b07c8309c542cafd07bed721f7.zip
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: Vaibhav 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: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e5df02c69b1d..01176788c387 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3569,6 +3569,30 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
}
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);