diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 454f42b..7643483 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2344,6 +2344,8 @@
 
 	tp720=		[HW,PS2]
 
+	trace_buf_size=nn[KMG] [ftrace] will set tracing buffer size.
+
 	trix=		[HW,OSS] MediaTrix AudioTrix Pro
 			Format:
 			<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>