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-rw-r--r--include/linux/ring_buffer.h1
-rw-r--r--kernel/trace/ring_buffer.c18
-rw-r--r--kernel/trace/trace.h15
3 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 56e27263acf8..cd7f0ae26615 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -192,6 +192,7 @@ void ring_buffer_record_off(struct trace_buffer *buffer);
void ring_buffer_record_on(struct trace_buffer *buffer);
bool ring_buffer_record_is_on(struct trace_buffer *buffer);
bool ring_buffer_record_is_set_on(struct trace_buffer *buffer);
+bool ring_buffer_record_is_on_cpu(struct trace_buffer *buffer, int cpu);
void ring_buffer_record_disable_cpu(struct trace_buffer *buffer, int cpu);
void ring_buffer_record_enable_cpu(struct trace_buffer *buffer, int cpu);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c0f877d39a24..1ca482955dae 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4883,6 +4883,24 @@ bool ring_buffer_record_is_set_on(struct trace_buffer *buffer)
}
/**
+ * ring_buffer_record_is_on_cpu - return true if the ring buffer can write
+ * @buffer: The ring buffer to see if write is enabled
+ * @cpu: The CPU to test if the ring buffer can write too
+ *
+ * Returns true if the ring buffer is in a state that it accepts writes
+ * for a particular CPU.
+ */
+bool ring_buffer_record_is_on_cpu(struct trace_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ return ring_buffer_record_is_set_on(buffer) &&
+ !atomic_read(&cpu_buffer->record_disabled);
+}
+
+/**
* ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer
* @buffer: The ring buffer to stop writes to.
* @cpu: The CPU buffer to stop
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 74f1fe5788d4..69c1ecfb2290 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -673,6 +673,21 @@ struct dentry *trace_create_file(const char *name,
void *data,
const struct file_operations *fops);
+
+/**
+ * tracer_tracing_is_on_cpu - show real state of ring buffer enabled on for a cpu
+ * @tr : the trace array to know if ring buffer is enabled
+ * @cpu: The cpu buffer to check if enabled
+ *
+ * Shows real state of the per CPU buffer if it is enabled or not.
+ */
+static inline bool tracer_tracing_is_on_cpu(struct trace_array *tr, int cpu)
+{
+ if (tr->array_buffer.buffer)
+ return ring_buffer_record_is_on_cpu(tr->array_buffer.buffer, cpu);
+ return false;
+}
+
int tracing_init_dentry(void);
struct ring_buffer_event;