Title: Timing Information
Description:
Timing measurements for the following features of the OS.
1. Context switch
Time taken to compete the context switch, i.e time spent in _Swap function.
2. Interrupt latency
Time taken from the start of the common interrupt handler till the
actual ISR handler being called.
3. Tick overhead
Time spent by the cpu in the tick handler.
4. Thread Creation
Time spent in creating a thread.
5. Thread cancel
Time taken to cancel the thread which is not yet started execution.
So the time taken to complete the function call is measured.
6. Thread abort
Time taken to abort the thread which has already started execution.
So the time measured is from the start of the function call until the
another thread is swapped in.
7. Thread Suspend
The time measured is from the start of the function call until the current
thread is suspended and another thread is swapped in.
8. Thread Resume
The time measured is from the start of the function call until the required
thread is resumed by swap operation.
9. Thread Yield
The time measured is from the start of the function call until the higher priority
thread is swapped in.
10. Thread Sleep
The time measured is from the start of the function call until the current
thread is put on the timeout queue and another thread is swapped in.
11. Heap Malloc
The time to allocate heap memory in fixed size chunks. Continuously allocate
the memory from the pool. Average time taken to complete the function call
is measured.
12. Heap Free
Time to free heap memory in fixed size chunks. Continuously free
the memory that was allocated. Average time taken to complete the function call
is measured.
13. Semaphore Take with context switch
Taking a semaphore causes a thread waiting on the semaphore to be swapped in.
Thus Time measured is the time taken from the function call till the waiting
thread is swapped in.
14. Semaphore Give with context switch
Giving a semaphore causes a thread waiting on the semaphore to be swapped
in (higher priority).
Thus Time measured is the time taken from the function call till the waiting
thread is swapped in.
15. Semaphore Take without context switch
Time taken to take the semaphore. Thus time to complete the function
call is measured.
16. Semaphore Give without context switch
Time taken to give the semaphore. Thus time to complete the function
call is measured.
17. Mutex lock
Time taken to lock the mutex. Thus time to complete the function
call is measured.
18. Mutex unlock
Time taken to unlock the mutex. Thus time to complete the function
call is measured.
19. Message Queue Put with context switch
A thread is waiting for a message to arrive. The time taken from the start
of the function call till the waiting thread is swapped in is measured.
20. Message Queue Put without context switch
The time taken to complete the function call is measured.
21. Message Queue get with context switch
A thread has gone into waiting because the message queue is full.
When a get occurs this thread gets free to execute. The time taken from
the start of the function call till the waiting thread is
swapped in is measured.
22. Message Queue get without context switch
The time taken to complete the function call is measured.
23. MailBox synchronous put
The time taken from the start of the function call till the waiting thread
is swapped in is measured.
24. MailBox synchronous get
The time taken from the start of the function call till the waiting thread
is swapped in is measured.
25. MailBox asynchronous put
The time taken to complete the function call is measured.
26. MailBox get without context switch
The time taken to complete the function call is measured.
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Building and Running Project:
This benchmark outputs to the console. It can be built and executed
on QEMU as follows:
make run
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Troubleshooting:
Problems caused by out-dated project information can be addressed by
issuing one of the following commands then rebuilding the project:
make clean # discard results of previous builds
# but keep existing configuration info
or
make pristine # discard results of previous builds
# and restore pre-defined configuration info
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Sample Output:
440b535602