6.2.5 Discussion

These two implementations show that it is possible to obtain uniprocessor performance for statistical counters, despite running on a parallel machine.

Quick Quiz 6.23: What fundamental difference is there between counting packets and counting the total number of bytes in the packets, given that the packets vary in size? End Quick Quiz

Quick Quiz 6.24: Given that the reader must sum all the threads' counters, this could take a long time given large numbers of threads. Is there any way that the increment operation can remain fast and scalable while allowing readers to also enjoy reasonable performance and scalability? End Quick Quiz

Given what has been presented in this section, you should now be able to answer the Quick Quiz about statistical counters for networking near the beginning of this chapter.



Paul E. McKenney 2011-12-16