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

[Sisu Xi]

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?

Thanks!

Sisu



On Wed, Apr 17, 2013 at 11:47 AM, Sisu Xi <xisisu at gmail.com> wrote:

> Hi, all:
>
> Is there any tutorial on running multiple rt tasks (say, rtspin) for some
> time and calculate the deadline miss ratio? like the ones you presented in
> the paper?
>
> I run a single rtspin task with wcet of 5 and period of 10 for 100
> seconds. There is no output of this.
>
> I can trace the task execution via reading /dev/litmus/log, it shows:
>
> 208107 P2: rt: adding rtspin/1357 (5000000, 10000000, 10000000)
> rel=1088752672478 to ready queue at 1088754177964
> 208108 P2: check_for_preemptions: attempting to link task 1357 to 1
> 208110 P2: (rtspin/1357:2350) blocks:0 out_of_time:0 np:0 sleep:1
> preempt:0 state:0 sig:0
> 208111 P2: (rtspin/1357:2350) job_completion().
> 208112 P2: rt: adding rtspin/1357 (5000000, 10000000, 10000000)
> rel=1088762672478 to ready queue at 1088764173889
> 208113 P2: check_for_preemptions: attempting to link task 1357 to 1
> 208115 P2: (rtspin/1357:2351) blocks:0 out_of_time:0 np:0 sleep:1
> preempt:0 state:0 sig:0
> 208116 P2: (rtspin/1357:2351) job_completion().
>
> I assume the 1357 is the pid, and the number following (2350, 2351, etc)
> is the job id. However, I don't know the exact job release time and job
> completion time. Thus I don't know whether this job missed its deadline or
> not.
>
> How do you guys trace the deadline miss ratio?
>
> Thanks very much!
>
> Sisu
>
>
>
> --
> 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
>



-- 
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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