[LITMUS^RT] running rtspin and calculate deadline miss ratio? -- Sisu

[Sisu Xi]

Hi, Björn

Thanks for your reply! This helps a lot!

Sisu



On Thu, Apr 18, 2013 at 12:46 PM, Björn Brandenburg <bbb at mpi-sws.org> wrote:

> On Apr 17, 2013, at 6:59 PM, Sisu Xi <xisisu at gmail.com> wrote:
>
> > Also, wouldn't tracing all these information cause lots of overhead when
> the system is running? thus interfere with the real-time task?
> >
> > I am thinking maybe we can use the base_task to do this. the process is
> like this:
> >
> > 1. first pre-calculate a fixed amount of CPU intensive workload on a
> particular machine, which consumes around 1ms
> > 2. allocate a large enough array in base_task to record the job
> completion time.
> > 3. wrap it with a for loop. parse the wcet to base_task, and within
> base_task, job() function, wrap a for loop to call this job this times. at
> the end of this for loop, record the time. This is the job completion time.
> > 4. given the task start time and period, we know how many job missed its
> deadline.
> >
> > what do you think about this?
>
>
> Make sure you run any benchmarks WITHOUT debug tracing enabled—debug
> tracing adds considerable overhead and should never be used to collect any
> benchmark information. Feather-Trace and sched_trace are much more
> efficient and should be used for all benchmarking purposes.
>
> Also, base_task.c is a starting point for custom experiment development—a
> tutorial, if you will. It is NOT intended to be run for benchmarking
> purposes, at least not as is. If you need something to consume cycles, use
> rtspin instead. If you want a meaningful workload, you can base it on
>  base_task.c, but you need to add the actual computation within each job
> yourself.
>
> - Björn
>
>
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-- 
Sisu Xi, PhD Candidate

http://www.cse.wustl.edu/~xis/
Department of Computer Science and Engineering
Campus Box 1045
Washington University in St. Louis
One Brookings Drive
St. Louis, MO 63130
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