[LITMUS^RT] Compiling the video src from Proceedings of the 32nd IEEE Real-Time Systems Symposium, pp. 93-103, December 2011

[Glenn Elliott]

Looking at the code in rtspin, it appears the file format is a csv with the following properties:
1) Execution time may be expressed in floating point.
2) Time is in milliseconds by default, but this can be scaled with rtspin's "-s" option.
3) The user specifies the column in the csv that contains execution times for the task with "-o".  I believe the first column of the csv is selected by default.
4) Each row in the csv denotes the execution time for a job.  So, the first row is for job_0, second row is for job_1, etc.
5) The rtspin will execute N jobs before terminating, where N is the number of rows.  There is no "looping back around".  I believe this implies that the "duration" argument to rtspin is ignored.
6) Only job execution times are read from the file.

Pertinent lines of code:
1) Reading the file: https://github.com/LITMUS-RT/liblitmus/blob/85cc826d76ad8bcfeb675710c49c410583cc86a9/bin/rtspin.c#L78
2) Column selection: https://github.com/LITMUS-RT/liblitmus/blob/85cc826d76ad8bcfeb675710c49c410583cc86a9/bin/rtspin.c#L248
3) Time unit scaling: https://github.com/LITMUS-RT/liblitmus/blob/85cc826d76ad8bcfeb675710c49c410583cc86a9/bin/rtspin.c#L374

rtspin's file format is a bit restrictive.  It was coded up for a particular paper where job execution times had to vary from job-to-job in a deterministic/repeatable way.  I don't know if this format was put in place for the video paper.  If so, it was probably done to allow the specification of different execution times for I-, P-, and B-frames.  It's not meant to be an alternative method of general use.  You may want to explore using input redirection to send regular command line arguments to rtspin (http://linuxcommand.org/lts0060.php).  Of course, you could also modify rtspin to do what you need.  The code is relatively straightforward.

-Glenn


On Sep 25, 2013, at 12:57 PM, ayoade gbadebo <gbaduz at gmail.com> wrote:

> Hello,
> Please what is the file input format for rtspin application.
> I want to generate a  set of random task using file and not command line parameters
> 
> 
> On Tue, Sep 24, 2013 at 9:38 AM, Björn Brandenburg <bbb at mpi-sws.org> wrote:
> 
> On Sep 24, 2013, at 4:07 PM, ayoade gbadebo <gbaduz at gmail.com> wrote:
> 
> > I tried comiling the video src from this paper but it complained of deprecated  fuctions, do you have any new source I can use ?
> >
> 
> That code is not part of the LITMUS^RT project and not maintained by us (the project). That said, you could try asking Chris (the first author), who wrote most of the video code if I recall correctly.
> 
> - Björn
> 
> 
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