Messages in this thread | | | Subject | Re: [PATCH] tracing: Update entries counter when removing pages | From | Steven Rostedt <> | Date | Fri, 29 Jun 2012 15:17:19 -0400 |
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On Fri, 2012-06-29 at 08:25 -0400, Steven Rostedt wrote: > 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.
Can you make this change and repost the patch. I'll start testing it if you can ASAP. Otherwise it will have to wait till next week.
-- Steve
> > local_sub(BUF_PAGE_SIZE, &cpu_buffer->entries_bytes); > > } > > >
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