Commit 48fdc72f authored Jun 29, 2012 by Vaibhav Nagarnaik Committed by Steven Rostedt Jun 29, 2012

ring-buffer: Fix accounting of entries when removing pages

When removing pages from the ring buffer, its state is not reset. This
means that the counters need to be correctly updated to account for the
pages removed.

Update the overrun counter to reflect the removed events from the pages.

Link: http://lkml.kernel.org/r/1340998301-1715-1-git-send-email-vnagarnaik@google.com



Cc: Justin Teravest <teravest@google.com>
Cc: David Sharp <dhsharp@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 44b99462

kernel/trace/ring_buffer.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1347,10 +1347,9 @@ rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned int nr_pages)
		* If something was added to this page, it was full
		* since it is not the tail page. So we deduct the
		* bytes consumed in ring buffer from here.
		* No need to update overruns, since this page is
		* deleted from ring buffer and its entries are
		* already accounted for.
		* Increment overrun to account for the lost events.
		*/
		local_add(page_entries, &cpu_buffer->overrun);
		local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes);
		}