- unstable 0~svn197-4
|dispatch_benchmark(3)||Library Functions Manual||dispatch_benchmark(3)|
Measures block execution time
count, void *context, void
function executes the given block multiple times
according to the count variable and then returns the
average number of nanoseconds per execution. This function is for debugging
and performance analysis work. For the best results, pass a high count value
dispatch_benchmark(). When benchmarking
concurrent code, please compare the serial version of the code against the
concurrent version, and compare the concurrent version on different classes
of hardware. Please look for inflection points with various data sets and
keep the following facts in mind:
- Code bound by computational bandwidth may be inferred by proportional changes in performance as concurrency is increased.
- Code bound by memory bandwidth may be inferred by negligible changes in performance as concurrency is increased.
- Code bound by critical sections may be inferred by retrograde changes in
performance as concurrency is increased.
- Intentional: locks, mutexes, and condition variables.
- Accidental: unrelated and frequently modified data on the same cache-line.
function returns the average number of nanoseconds the given block takes to
|May 1, 2009||Darwin|