Posts that commenters keep linking to, ranked by how many different people have cited them in Hacker News comments. 696 posts.
I recently hit some multi-minute delays on my workstation. After investigating I found that the problem was due to a lock being held for five minutes, and during that time the lock-holder was mostl…
DTrace for Linux 2016: announcing a major milestone: the final kernel capabilities have merged in Linux 4.9-rc1 to enhanced BPF (eBPF) to provide an advanced programmable dynamic tracer similar to DTrace.
Performance comparison of counting and sorting word frequencies in various languages (Python, Go, C++, C, AWK, Forth, and Rust)
Hello friends, this is the first of two, possibly three (if and when I have time to finish the Windows research) writeups. We will start with targeting GNU/Lin…
Linux in a Pixel Shader - A RISC-V Emulator for VRChat
After beginning a compiler for the Apple M1 GPU , the next step is to develop a graphics driver exercising the compiler. Since the last post two weeks ago, I’ve begun a Gallium driver for the M1, implementing much of the OpenGL 2.1 and ES 2.0 specifications. With the compiler and driver together, we’re now able to run…
It's time for servers to handle 10 million simultaneous connections, don't you think? After all, computers now have 1000 times the memory as...
Posts and writings by Lennart Poettering
We assume that browser caches are near-instantaneous, but data shows that retrieving an object from cache can take hundreds of milliseconds!
Some notes on the different patterns that may be present when people talk about event-driven architectures.
I think I first heard about the Zstandard compression algorithm at a Mercurial developer sprint in 2015. At one end of a large table a few people were uttering expletives out of sheer excitement. At developer gatherings, that's the universal signal for something is awesome . Long story short, a Facebook engineer…
Posts and writings by Lennart Poettering
When Windows NT was first being developed, one of the goals was to make the kernel separate from the programming interface. NT was originally intended to be the successor to OS/2 but Microsoft also…
Updated (February 07 2013): If you enjoy this article, you may also find the more academically-inclined article The Impact of Meta-Tracing on VM Design and Implementation interesting.
There’s a neat variation on open-addressing based hash tables called Robin Hood hashing . This technique isn’t very well-known, but it makes a huge practical difference because it both improves performance and space utilization compared to other “standard” hash tables (e.g. chaining ). It also eliminates the major…
Typical server utilization is between 10% and 50%. Google has demonstrated 90% utilization without impacting latency SLAs . Xkcd estimated that Google owns 2 million machines . If you estimate an amortized total cost of $4k per machine per year , that's $8 billion per year. With numbers like that, even small…
Vyacheslav Egorov, who goes by mraleph on the Web, wrote a responseto my article “Oxidizing Source Maps with Rust and WebAssembly”titled “Maybe you don’t nee...
Recently the topic of systemd has come up quite a bit in various communities in which I'm involved, including the musl IRC channel and on the Busybox mailing list .
UPDATE: Oracle officially released memcached daemon plugin that talks with InnoDB. I'm glad to see that NoSQL+MySQL has become an official ...
In the previous Jepsen analysis of RethinkDB , we tested single-document reads, writes, and conditional writes, under network partitions and process pauses. RethinkDB did not exhibit any nonlinearizable histories in those tests. However, testing with more aggressive failure modes, on both 2.1.5 and 2.2.3, has…
Since this article contains a lot of interactive demos relying on fairly modern browser technology, let's make sure that everything is OK before continuing.
The default timer resolution on Windows is 15.6 ms – a timer interrupt 64 times a second. When programs increase the timer frequency they increase power consumption and harm battery life. They also…
This sounds unusual. Who ever wants to do this in real life? Normally, we only see code like this as primary school assignments or compiler benchmarks. However, this time it happened in real life.
See also Dennis Ritchie on aliasing, PLOS article , pointer alias in C and remarks on the purpose of C.
