Messages in this thread Patch in this message | | | Date | Thu, 12 Mar 2009 22:37:05 -0400 | From | Steven Rostedt <> | Subject | [PATCH 01/16] tracing: fix comments about trace buffer resizing |
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From: Steven Rostedt <srostedt@redhat.com>
Impact: cleanup
Some of the comments about the trace buffer resizing is gobbledygook. And I wonder why people question if I'm a native English speaker.
This patch makes the comments make a bit more sense.
Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Steven Rostedt <srostedt@redhat.com> --- 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 c3946a6..c61ee85 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; } -- 1.6.1.3 --
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