From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Thu, 11 May 2017 20:42:34 +0000 (-0400)
Subject: Revert "Fix: don't perform extra flush on metadata channel"
X-Git-Tag: v2.9.3~13
X-Git-Url: http://git.lttng.org/?p=lttng-modules.git;a=commitdiff_plain;h=1e8d53a9f3e8b6d7a7434a442d449e3ccf9c12b0

Revert "Fix: don't perform extra flush on metadata channel"

This reverts commit 7cf44d034bdda1896f6b0c6374c90c06d45ee4fd.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/lib/ringbuffer/frontend_internal.h b/lib/ringbuffer/frontend_internal.h
index 88820f7e..3a229ff8 100644
--- a/lib/ringbuffer/frontend_internal.h
+++ b/lib/ringbuffer/frontend_internal.h
@@ -168,9 +168,6 @@ void lib_ring_buffer_check_deliver_slow(const struct lib_ring_buffer_config *con
 extern
 void lib_ring_buffer_switch_remote(struct lib_ring_buffer *buf);
 
-extern
-void lib_ring_buffer_switch_remote_empty(struct lib_ring_buffer *buf);
-
 /* Buffer write helpers */
 
 static inline
diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
index 68b62382..8a6a1883 100644
--- a/lib/ringbuffer/ring_buffer_frontend.c
+++ b/lib/ringbuffer/ring_buffer_frontend.c
@@ -1075,6 +1075,15 @@ int lib_ring_buffer_snapshot(struct lib_ring_buffer *buf,
 	unsigned long consumed_cur, write_offset;
 	int finalized;
 
+	/*
+	 * First, ensure we perform a "final" flush onto the stream.  This will
+	 * ensure we create a packet of padding if we encounter an empty
+	 * packet. This ensures the time-stamps right before the snapshot is
+	 * used as end of packet timestamp.
+	 */
+	if (!buf->quiescent)
+		_lib_ring_buffer_switch_remote(buf, SWITCH_FLUSH);
+
 retry:
 	finalized = ACCESS_ONCE(buf->finalized);
 	/*
@@ -1839,13 +1848,6 @@ 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
diff --git a/lib/ringbuffer/ring_buffer_vfs.c b/lib/ringbuffer/ring_buffer_vfs.c
index 15da212d..f1a8bab7 100644
--- a/lib/ringbuffer/ring_buffer_vfs.c
+++ b/lib/ringbuffer/ring_buffer_vfs.c
@@ -191,15 +191,6 @@ long lib_ring_buffer_ioctl(struct file *filp, unsigned int cmd,
 
 	switch (cmd) {
 	case RING_BUFFER_SNAPSHOT:
-		/*
-		 * First, ensure we perform a "final" flush onto the
-		 * stream.  This will ensure we create a packet of
-		 * padding if we encounter an empty packet. This ensures
-		 * the time-stamps right before the snapshot is used as
-		 * end of packet timestamp.
-		 */
-		if (!buf->quiescent)
-			lib_ring_buffer_switch_remote_empty(buf);
 		return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 					    &buf->prod_snapshot);
 	case RING_BUFFER_SNAPSHOT_GET_CONSUMED:
@@ -329,15 +320,6 @@ long lib_ring_buffer_compat_ioctl(struct file *filp, unsigned int cmd,
 
 	switch (cmd) {
 	case RING_BUFFER_COMPAT_SNAPSHOT:
-		/*
-		 * First, ensure we perform a "final" flush onto the
-		 * stream.  This will ensure we create a packet of
-		 * padding if we encounter an empty packet. This ensures
-		 * the time-stamps right before the snapshot is used as
-		 * end of packet timestamp.
-		 */
-		if (!buf->quiescent)
-			lib_ring_buffer_switch_remote_empty(buf);
 		return lib_ring_buffer_snapshot(buf, &buf->cons_snapshot,
 						&buf->prod_snapshot);
 	case RING_BUFFER_COMPAT_SNAPSHOT_GET_CONSUMED:
diff --git a/lttng-abi.c b/lttng-abi.c
index 478a5912..3e4a88c1 100644
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -704,18 +704,6 @@ long lttng_metadata_ring_buffer_ioctl(struct file *filp,
 
 		return put_u64(stream->version, arg);
 	}
-	case RING_BUFFER_SNAPSHOT:
-	{
-		/*
-		 * Force the buffer to quiescent so the ring buffer
-		 * don't attempt to perform a SWITCH_FLUSH, which would
-		 * desynchronize the client accounting of the amount of
-		 * data available in the buffer from the ring buffer
-		 * view.
-		 */
-		buf->quiescent = true;
-		break;
-	}
 	default:
 		break;
 	}
@@ -792,18 +780,6 @@ long lttng_metadata_ring_buffer_compat_ioctl(struct file *filp,
 
 		return put_u64(stream->version, arg);
 	}
-	case RING_BUFFER_SNAPSHOT:
-	{
-		/*
-		 * Force the buffer to quiescent so the ring buffer
-		 * don't attempt to perform a SWITCH_FLUSH, which would
-		 * desynchronize the client accounting of the amount of
-		 * data available in the buffer from the ring buffer
-		 * view.
-		 */
-		buf->quiescent = true;
-		break;
-	}
 	default:
 		break;
 	}