Revert "Fix: flush empty packets on snapshot channel"

[lttng-modules.git] / lib / ringbuffer / ring_buffer_frontend.c

diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
index 68b62382e9fc87c2a307887cc67e144dfe1528a8..8b15ec7a2417f0062d98b9b3676799dd76152e58 100644 (file)
--- a/lib/ringbuffer/ring_buffer_frontend.c
+++ b/lib/ringbuffer/ring_buffer_frontend.c
@@ -1464,8 +1464,7 @@ void lib_ring_buffer_print_errors(struct channel *chan,
 /*
  * lib_ring_buffer_switch_old_start: Populate old subbuffer header.
  *
- * Only executed by SWITCH_FLUSH, which can be issued while tracing is active
- * or at buffer finalization (destroy).
+ * Only executed when the buffer is finalized, in SWITCH_FLUSH.
  */
 static
 void lib_ring_buffer_switch_old_start(struct lib_ring_buffer *buf,
@@ -1661,14 +1660,12 @@ int lib_ring_buffer_try_switch_slow(enum switch_mode mode,
                unsigned long sb_index, commit_count;
 
                /*
-                * We are performing a SWITCH_FLUSH. There may be concurrent
-                * writes into the buffer if e.g. invoked while performing a
-                * snapshot on an active trace.
+                * We are performing a SWITCH_FLUSH. At this stage, there are no
+                * concurrent writes into the buffer.
                 *
-                * If the client does not save any header information (sub-buffer
-                * header size == 0), don't switch empty subbuffer on finalize,
-                * because it is invalid to deliver a completely empty
-                * subbuffer.
+                * The client does not save any header information.  Don't
+                * switch empty subbuffer on finalize, because it is invalid to
+                * deliver a completely empty subbuffer.
                 */
                if (!config->cb.subbuffer_header_size())
                        return -1;
@@ -1839,13 +1836,6 @@ void lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf)
 }
 EXPORT_SYMBOL_GPL(lib_ring_buffer_switch_remote);
 
-/* Switch sub-buffer even if current sub-buffer is empty. */
-void lib_ring_buffer_switch_remote_empty(struct lib_ring_buffer *buf)
-{
-       _lib_ring_buffer_switch_remote(buf, SWITCH_FLUSH);
-}
-EXPORT_SYMBOL_GPL(lib_ring_buffer_switch_remote_empty);
-
 /*
  * Returns :
  * 0 if ok