Nitpick - `77 percent faster` is not the inverse of `77 percent slower`. The line that says `The results of this microbenchmark show that the vDSO method is about 77% faster` should read `446% faster`.
Should that not be 346% faster? If A takes 1 second and B takes two seconds, then B is 100% faster than A. So the calculation would be (B/A - 1) * 100. Applying this here gives around 346%.
EDIT: B would, of course, take 100% longer than A, rather than be 100% faster.
You're right, of course: hadn't had the morning coffee. It should have been 'takes 100% longer' in the 1 second/2 seconds example. The point I was trying to make is that you have to factor in the initial 100% which doesn't contribute to the final value.
[1]: https://blog.packagecloud.io/eng/2016/04/05/the-definitive-g...