X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_vfs.c;h=15da212d3fa313e3b3a027b2638132cacbb1db40;hb=7cf44d034bdda1896f6b0c6374c90c06d45ee4fd;hp=f1a8bab781cd2f5829c552067eefdb2365c1f2e7;hpb=a6370148ab4a6f210c29372febcffd87b440cc50;p=lttng-modules.git

diff --git a/lib/ringbuffer/ring_buffer_vfs.c b/lib/ringbuffer/ring_buffer_vfs.c
index f1a8bab7..15da212d 100644
--- a/lib/ringbuffer/ring_buffer_vfs.c
+++ b/lib/ringbuffer/ring_buffer_vfs.c
@@ -191,6 +191,15 @@ 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:
@@ -320,6 +329,15 @@ 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: