Exercise 6
Implement two scripts: mtxtime.d
and mtxtimd.stp
that would compute delay between attempt to acquire a userspace mutex and a moment when mutex is acquired. Group times by user stacks and print data as logarithmic histograms.
Use pthread
experiment to demonstrate your scripts, like in previous section, TSLoad workload generator itself would be an object in the experiment. Try to identify mutexes that show delays larger than 1 ms.
Warning
To prevent problems with symbol resolving in DTrace after tracing process finishes, you can attach to a function experiment_unconfigure()
from tsexperiment
to print gathered data.