[LITMUS^RT] measuring tardiness for jobs scheduled by sched fifo

[Björn Brandenburg]

> On 17.04.2014, at 08:04, ayoade gbadebo <gbaduz at gmail.com> wrote:
> 
> I am trying to measure job tardiness of real time jobs scheduled under schedfifo..
> how can this be done at kernel level since job period and deadline are not passed as parameters to using sched fifo scheduler as compared to litmus scheduler where all the parameter is passed to the kernel through an api at runtime

LITMUS^RT does not provide tracing infrastructure for SCHED_FIFO. You may be able to hack the existing infrastructure to collect the info that you need. 

To communicate the period etc. to the kernel, you can actually set the LITMUS^RT scheduling parameters for SCHED_FIFO tasks. However, you will have to modify the kernel to emit appropriate trace records for SCHED_FIFO tasks. If you come up with a clean and preferably minimally invasive patch, this might be something worth merging. 

Thanks,
Björn