Messages in this thread | | | Date | Mon, 22 Sep 2008 20:04:37 -0400 | From | Masami Hiramatsu <> | Subject | Re: Unified tracing buffer |
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Hi Darren,
Darren Hart wrote: > On Mon, Sep 22, 2008 at 3:25 PM, Masami Hiramatsu <mhiramat@redhat.com> wrote: > >>> One thing that I think is still important is to have a unified timestamp >>> mechanism on everything, so we can co-ordinate different things back >>> together in userspace from different trace tools, so I intend to keep >>> that at a lower level, but I think you're right that the event id, etc can >>> move up into separate layers. >> I'm not so sure that the unified 'timestamp' must be required by all tracers. >> If you just need to merge and sort per-cpu data, you can use an atomic >> sequential number for it. >> IMHO, the unified 'timestamp' would better be an option, because some >> architectures can't support it. I think preparing timestamp-callback >> function will help us. >> > > There have been several posts on the timestamp for the events. From a > real-time perspective, this timestamp will be a very important datapoint for > each event, and the more accurate/higher resolution the better. Some thoughts.
Sure, I know the precise timestamp is required for real-time sensitive tracers. however, there are some other cases. for example debugging, we don't need timestamps, but just want to know the order of events. :-)
Thank you,
-- Masami Hiramatsu
Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division
e-mail: mhiramat@redhat.com
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