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The most popular blog posts about systems & performance on Hacker News. 377 posts.
You're probably reading this page because you've attempted to access some part of my blog (Wandering Thoughts) or CSpace , the wiki thing it's part of. Unfortunately you're using a browser version that my anti-crawler precautions consider suspicious, most often because it's too old (most often this applies to versions…
For quite some time—as my research will show, March 2016—, I have been annoyed by a directory named --help showing up in my home directory (and sometimes in others).
This is Part 6 over 6 of "Coding for SSDs". For other parts and sections, you can refer to the Table to Contents. This is a series of articles that I wrote to share what I learned while documenting myself on SSDs, and on how to make code perform well on SSDs. In this part,
DEFLATE is a relatively slow compression algorithm from 1991, which (along with its wrapper format, zlib) is incredibly widely used, for example in the PNG, Zip and Gzip file formats and the HTTP, …
macOS manages the loading and frequency of M1 cores according to the QoS set, and rules which differ between the original M1 and the M1 Pro.
A head-to-head performance comparison between the Linux kernel's network stack, and a kernel-bypass stack powered by DPDK.
Many recent Intel processors benefit from a new family of instructions called AVX-512. These instructions operate over wide registers (up to 512 bits) and follow the Single instruction, multiple data (SIMD) paradigm. These new AVX-512 instructions allow you to break some speed records, such as decoding base64 data at…
There are various ways in software to handle error conditions. In C or Go, one returns error code. Other programming languages like C++ or Java prefer to throw exceptions. One benefit of using exceptions is that it keeps your code mostly clean since the error-handling code is often separate. It is debatable whether…
Here’s a not-so-brief story about troubleshooting a problem that was at times vexing, impossible, incredibly challenging, frustrating, and all around just a terrible time with the bare-metal STM32G4 firmware for the moteus brushless motor controller. Background First, some things for context: moteus has a variety of…
Freshly whipped WebGPU, with ice cream
When running some tasks confined to E cores, the original M1 chip from 2020 completes them significantly quicker than an on an M1 Pro. Here’s the detail.
Microsoft is increasingly standardizing on its in-house CBL-Mariner Linux distribution. Is this Microsoft Linux?
The system memory allocator free operation zeroes out all deallocated blocks in iOS 16.1 beta or later. Invalid accesses to free memory might result in new crashes or corruption, including NULL -pointer dereferences and non-zero memory being returned from calloc .
I’m more surprised by the nature of many of these issues, by how ridiculous they are compared with the sheer age and supposed maturity of a 20+ year-old operating system.
While considering concurrent queue design I came up with a generic, lock-free queue that fits in a 32-bit integer. The queue is “generic” in that a single implementation supports elements of any arbitrary type, despite an implementation in C. It’s lock-free in that there is guaranteed system-wide progress. It can…
CPUs like to operate on data types such as uint8_t , uint16_t , uint32_t , and uint64_t . These data types can be viewed as integers modulo 2 8 , 2 16 , 2 32 , and 2 64 respectively. Addition and multiplication can be defined on these integers modulo 2 N in a way which is familiar to most people; for example, in…
We use distributed systems every day in the form of internet services. These systems are very useful, but also challenging to implement because networks are unpredictable. Whenever you send a message over the network, it is likely to arrive quite quickly, but it’s possible that it might be delayed for a long time, or…
While browsing twitter, I came across this tweet:
The OS/2 Museum has made available the first version of a display driver disk for Windows 9x running on VirtualBox . The driver uses a linear framebuffer and supports 8/16/24/32bpp modes with resolutions up to 1920×1200 pixels (see more below). The driver is not accelerated but tends to be very speedy on modern…
Wikipedia cites a few different sources on what “Unix Philosophy” is. Peter Salus summarizes it as:
sysctl is a simple and great tool for modifying the kernel parameters. It does its job very well by providing an easy-to-use interface for /proc/sys. It is maintained as a part of procps toolkit for years and it can easily be considered a legacy tool today. So why not push it to its limits and turn it into a more…
In this post, we will explore how to build a high-performance database buffer pool in Zig using io_uring's new fixed-buffer mode.
Posts and writings by Lennart Poettering
What's the big deal about key-value databases like FoundationDB and RocksDB?
This post is the fourth part of a three-part series 1 describing work that I have been doing to improve the Cranelift compiler. In this post, I'll describe the work that went into regalloc2 , a new register allocator I developed over the past year. The allocator started as an effort to port IonMonkey's register…
