diff options
| -rw-r--r-- | kernel/trace/trace.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c3946a6df34..c61ee85c50b 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; } |