mp := b.mp()
		fn(b, b.nstk, &b.stk()[0], b.size, mp.active.allocs, mp.active.frees)
	}
	unlock(&profMemActiveLock)
}

// BlockProfileRecord describes blocking events originated
// at a particular call sequence (stack trace).
type BlockProfileRecord struct {
	Count  int64
	Cycles int64
	StackRecord
}

// BlockProfile returns n, the number of records in the current blocking profile.