Blogs by Erik
Tech blog on web, security & embedded
Low power & low frustration (video)
Our year in Rust
Our year in Rust
A company-changing year in a short story,
begins with a thank you, for this new-found glory.
We want to be clear in this prelude,
It is to Rust we owe our gratitude.
Meetup: Rust in open-source critical infrastructure
Implementing the Network Time Protocol (NTP) in Rust
For the last couple of months we at Tweede golf have been working on implementing a Network Time Protocol (NTP) client and server in Rust.
The project is a Prossimo initiative and is supported by their sponsors, Cisco and AWS. Our first short-term goal is to deploy our implementation at Let's Encrypt. The long-term goal is to develop an alternative fully-featured NTP implementation that can be widely used.
Introducing Rust in security research
Why is Rust loved? 5 developers, 5 stories
Instant data retrieval from large point clouds
The Dutch government offers the AHN [](https://www.ahn.nl/) as a way to get information about the height of any specific place in the country. They offer this data by using a point cloud. That is, a large set of points with some additional meta information. With the current version of the AHN the resolution of the dataset is about eight points per square meter. This results in about 2.5TB of compressed data for the relatively small area of the Netherlands. While this is something that is not impossible to store locally, it does offer some challenges.
Open Data geeft het antwoord: hoe groen is mijn wijk?
Sorting with SIMD
Google recently published a blog article and paper introducing their SIMD-accelerated sorting algorithm.
SIMD stands for single instruction, multiple data. A single instruction is used to apply the same operation to multiple pieces of data. The prototypical example is addition, where one instruction can do e.g. 4 32-bit additions. A single SIMD addition should be roughly 4 times faster than performing 4 individual additions.
This kind of instruction-level parallelism has many applications in areas with a lot of number crunching, e.g. machine learning, physics simulations, and game engines. But how can this be used for sorting? Sorting does not involve arithmetic, and the whole idea of sorting is that each element moves to its unique correct place in the output. In other words, we don't want to perform the same work for each element, so at first sight it's hard to see where SIMD can help.
To understand the basic concepts, I played around with the ideas from the paper Fast Quicksort Implementation Using AVX Instructions by Shay Gueron and Vlad Krasnov. They provide an implementation in (surprisingly readable) assembly on their github. Let's see how we can make SIMD sort.