Question

How to use linsched (Linux scheduler simulator)? In need of an example on how to run and check the output. Have been searching for tutorials and also went through the README file. Din’t understand how to run and checkout the outputs. Tried running basic_tests script (as ./basic_tests trivial_bal UNIPROCESSOR) but, it din’t show up anything, .. Thanks in advance..

Answer 1

You can’t be the only one having this problem! It was not trivial to get a small example running.

For every test you want output (everybody wants output, except for the person who wrote the tests obviously), add linsched_print_task_stats(); at the end of the test and recompile.

If you want to add an own test, for example listing 4 in http://www.ibm.com/developerworks/linux/library/l-linux-scheduler-simulator/ do like this:

1. Copy the code in listing 4 to the bottom of basic_test.c
2. initialize the variable count to zero or some other good value.
3. Change topo_db to linsched_topo_db
4. change the function name to test_new_test
5. Add TEST(new_test), to struct test tests[], but NOT at the bottom because the last one is used as a sentinel when printing.
6. Add the function as forward declaration at the top of the file void test_new_test(int argc, char **argv);
7. Compile and run: /basic_tests list

trivial_bal
basic_bal1
basic_bal2
bal1
new_test

8. Try your new command.
   ./basic_tests new_test uniprocessor

Task id = 3 (1), exec_time = 7116000000, run_delay = 52092000000,  
Task id = 4 (2), exec_time = 7116000000, run_delay = 52093000000,  
Task id = 5 (3), exec_time = 7116000000, run_delay = 52094000000,  
Task id = 6 (4), exec_time = 7115000000, run_delay = 52095000000,  
Task id = 7 (5), exec_time = 7115000000, run_delay = 52091000000,  
Task id = 8 (6), exec_time = 3430000000, run_delay = 25771000000,  
Task id = 9 (7), exec_time = 3430000000, run_delay = 25772000000,  
Task id = 10 (8), exec_time = 3430000000, run_delay = 25773000000,   
Task id = 11 (9), exec_time = 3430000000, run_delay = 25774000000,  
Task id = 12 (10), exec_time = 3430000000, run_delay = 25775000000,  
Task id = 13 (11), exec_time = 7272000000, run_delay = 52725000000,  
Total exec_time = 60000000000

The link I mentioned above has a very good explanation on how to interpret the numbers.
Good luck with the scheduling!