contention_stats.stp

global hist
global total
global contended
global syscalls

// Trying to acquire
probe process("/lib64/libpthread.so.0").statement("__pthread_mutex_lock@pthread_mutex_lock.c+64") {
	total++
}

// Lock was not immediately available, beginning to spin
probe process("/lib64/libpthread.so.0").statement("__pthread_mutex_lock@pthread_mutex_lock.c+66") {
	contended++
}

probe process("/lib64/libpthread.so.0").statement("__pthread_mutex_lock@pthread_mutex_lock.c+80") {
	numspins = $cnt
	hist <<< numspins
}

probe process("/lib64/libpthread.so.0").statement("__pthread_mutex_lock@pthread_mutex_lock.c+73") {
	syscalls++
}

probe end {
	printf("total: %d contended: %d went to kernel: %d\n", total, contended, syscalls);
	println("histogram of spin iterations:");
	print(@hist_log(hist));
}