Messages in this thread | | | From | David Sharp <> | Date | Tue, 26 Jun 2012 17:35:34 -0700 | Subject | Re: [PATCH] ring-buffer: fix uninitialized read_stamp |
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On Fri, Jun 22, 2012 at 6:27 PM, David Sharp <dhsharp@google.com> wrote: > On Fri, Jun 22, 2012 at 4:31 PM, Steven Rostedt <rostedt@goodmis.org> wrote: >> >> Now I think you may understand my patch. > > Yeah, mostly. At least enough that I think it's worth testing. But Monday.
I got around to testing your patch today, and it fixes the issue. No bad-looking timestamps in 40 runs, whereas could reproduce within 3 runs before. Do you want me to send you a fresh patch, or just use the one you have?
>>> On Thu, Jun 21, 2012 at 8:56 AM, Steven Rostedt <rostedt@goodmis.org> wrote: >>> > Does something like this work for you. Note, this is totally untested! >>> > >>> > -- Steve >>> > >>> > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c >>> > index ad0239b..5943044 100644 >>> > --- a/kernel/trace/ring_buffer.c >>> > +++ b/kernel/trace/ring_buffer.c >>> > @@ -3246,6 +3246,10 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) >>> > if (cpu_buffer->commit_page == cpu_buffer->reader_page) >>> > goto out; >>> > >>> > + /* Don't bother swapping if the ring buffer is empty */ >>> > + if (rb_num_of_entries(cpu_buffer) == 0) >>> > + goto out; >>> > + >>> > /* >>> > * Reset the reader page to size zero. >>> > */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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