THREE DIFFERENCES BETWEEN RTOS & NORMAL OS

[sacrpio]

need of rtos over normal os

HELLO,

Can anybody tell me only three differences which RTOS support not normal OS excluding this difference that RTOS is time deterministic.

How we will prove RTOS is time deterministic. (give any example)

bye..

 

[raj_rohit10]

what is the difference between rtos and os

1. In RTOS user can decide the scheduling pattern.
It is generally priority based scheduling.But as per the requirement user can modify.
2. In RTOS preemption is there like the heigher priority task can preempt the lower priority task.

 

[sacrpio]

rtos preemption

Dear friends,
Both things are supported UNIX also.
I want totally different answer.
bye..

 

[raj_rohit10]

As far as your query regarding how to find if the RTOS is time deterministic, well one has to design the system which full fills all the time constraints. If the required time constraints are too stingent and cant be handled by the current RTOS, then such system will never be time deterministic.

 

[goshka]

imxo,
If late response of emdedded system are so badly as no responce/incorrect responce, You need RTOS.

If overlapped A B C event processing logic depends of its entry order, You need RTOS.

**broken link removed**

 

[kshitij_s81]

HELLO,
Well the difference between rtos and a normal os is that rtos is time detterministic,probabilistic and has a micro kernel instead of a whole kernel as in the case of a normal os.In the case of finding time deterministic we can either use rm(rate monotonic) or dm(deadtime monotonic) schedulingwith the help of edf or lst algo.
bye..

 

[lunark]

1 preemptive muti priority schedule
2 flat memory alloction
3 used by RISC cpu

 

[caliph]

Look for timing guaratees from the OS vendor for:

1. Time delay incurred to switch to next (or higher priority) task after that task becomes ready.

2. Time delay incurred from the time interrupt is received to the time the system begins servicing it (ISR starts)

Both these delays should be independent of the current load on the system.

Apart from this one difference, an RTOS is just like a normal OS (same memory management, task scheduling, semaphores, message queues etc.). It's only the time guarantee that makes all the difference.