Messages in this thread | | | Subject | Re: [PATCH] tracing: Update entries counter when removing pages | From | Steven Rostedt <> | Date | Fri, 29 Jun 2012 08:25:41 -0400 |
| |
On Mon, 2012-06-18 at 12:12 -0700, Vaibhav Nagarnaik wrote: > 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 entries counter to reflect the removed events from the > pages just like entries_bytes counter. > > Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> > --- > kernel/trace/ring_buffer.c | 6 +++--- > 1 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 96c2dd1..a2bec4c 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -1346,10 +1346,10 @@ 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. > + * No need to update overruns, since updating > + * 'entries' accounts for that. > */ > + local_sub(page_entries, &cpu_buffer->entries);
Actually, I think it would be better to increment overrun instead. As these are lost events, and that is what overrun counts. I just tested it with: local_add(page_entries, &cpu_buffer->overrun); and it works well. Showing the lost events.
-- Steve
> local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes); > } >
| |