1 files changed, 16 insertions, 3 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index c3946a6df34e..c61ee85c50bb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2336,7 +2336,8 @@ static int tracing_resize_ring_buffer(unsigned long size)
 
         /*
          * If kernel or user changes the size of the ring buffer
-         * it get completed.
+         * we use the size that was given, and we can forget about
+         * expanding it later.
          */
         ring_buffer_expanded = 1;
 
@@ -2351,8 +2352,20 @@ static int tracing_resize_ring_buffer(unsigned long size)
                 r = ring_buffer_resize(global_trace.buffer,
                                        global_trace.entries);
                 if (r < 0) {
-                        /* AARGH! We are left with different
-                         * size max buffer!!!! */
+                        /*
+                         * AARGH! We are left with different
+                         * size max buffer!!!!
+                         * The max buffer is our "snapshot" buffer.
+                         * When a tracer needs a snapshot (one of the
+                         * latency tracers), it swaps the max buffer
+                         * with the saved snap shot. We succeeded to
+                         * update the size of the main buffer, but failed to
+                         * update the size of the max buffer. But when we tried
+                         * to reset the main buffer to the original size, we
+                         * failed there too. This is very unlikely to
+                         * happen, but if it does, warn and kill all
+                         * tracing.
+                         */
                         WARN_ON(1);
                         tracing_disabled = 1;
                 }