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Linux maintains bugs: The real reason ifconfig on Linux is deprecated (2018)
In my third installment of FreeBSD vs Linux, I will discuss underlying reasons for why Linux moved away from ifconfig(8) to ip(8).
Topics /
Systems & Performance
The most popular blog posts about systems & performance on Hacker News. 4,387 posts.
1202
Speeding up atan2f
`atan2f` is an important but slow trigonometric function. In this article we'll explain how to approximate it, and implement a version 50x faster than `glibc` on batches of inputs.
1203
How to stop Linux threads cleanly
Stopping a Linux thread is a surprisingly annoying affair. In this post I present common pitfalls and some solutions -- although no truly satisfactory method exists.
1204
Why Prefetch Is Broken
When coding a webpage, sometimes you know something is very likely to be needed, even if it's not needed yet. You can give the browser a hint: <link rel=prefetch href=url> The browser will take a note, and then when it doesn't have anything more important to do it might request url. Later on, if it does turn out…
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When Parallel: Pull, Don't Push
I’ve noticed a small pattern across a few of my projects where I had vectorized and parallelized some code. The original algorithm had a “push” approach, the optimized version instead took a “pull” approach. In this article I’ll describe what I mean, though it’s mostly just so I can show off some pretty videos…
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Mistakes we made adopting event sourcing and how we recovered
Good judgement is the result of experience ... Experience is the result of bad judgement. — Fred Brooks
1209
How a computer boots up
The previous post described [motherboards and the memory map] memory-map in Intel computers to set the scene for the initial phases of boot. Booting is an involved, hacky, multi-stage affair - fun st
1210
Please restore our registers when you’re done with them
“Hey, you. Yes you, that function over there. When you’re cleaning up please remember to restore all of my registers. Yes, that one too – what do you think this is, Linux?”That’s the problem I was …
1211
Honey, I shrunk {fmt}: bringing binary size to 14k and ditching the C++ runtime
The {fmt} formatting library is known for its small binary footprint, often producing code that is several times smaller per function call compared to alternatives like IOStreams, Boost Format, or, somewhat ironically, tinyformat. This is mainly achieved through careful application of type erasure on various levels…
1212
A Look at PureDarwin – An OS Based on the Open Source Core of macOS
An overview of the PureDarwin project, which is a community effort to produce a more usable version of Darwin OS, the open source base behind modern Mac OS.
1213
When compilers surprise you
Sometimes compilers can surprise and delight even a jaded old engineer like me
1214
SeL4 is verified on RISC-V
Sounds great! But what does it mean? seL4 seL4 (pronounced ess-e-ell-four) is arguably the world’s most secure operating system (OS) kernel. The OS kernel is the lowest level of software runn…
1215
On modern hardware the min-max heap beats a binary heap
The heap is a data structure that I use all the time and that others somehow use rarely. (I once had a coworker tell me that he knew some code was mine because it used a heap) Recently I was writin…
1216
The TTY demystified (2008)
The TTY subsystem is central to the design of Linux, and UNIX in general. Unfortunately, its importance is often overlooked, and it is difficult to find good introductory articles about it. I believe that a basic understanding of TTYs in Linux is essential for the developer and the advanced user.
1217
Bug hunting in Btrfs
The other day I was implementing multi-threaded stat() calls in bfs . When I ran some benchmarks, I saw something that made my heart skip a beat:
1218
64-bit ARM desktop hardware?
Soon there will be four years since I started working on AArch64 architecture. Lot of software things changed during that time. Lot in a hardware too. But machines availability still sucks badly. In 2012 all we had was software model. It was slow, terribly slow. Common joke was AArch64 developers …
1219
Anti-patterns in event-driven architecture
Event-driven architecture is great, but it can cause a lot of headaches if it is used for the wrong purpose.
1220
Libc++'s Implementation of std::string
I. Introduction
1221
Hardware-accelerated Linux virtual machines on jailbroken iPhone 12 / iOS 14.1
I unlocked Hypervisor.framework on my jailbroken phone and modified UTM, a popular QEMU port for iOS, to run arm64 Linux in a VM at full native speed. …for the clickbait - and to show iPhone’s untapped potential.
1222
Call Me Maybe: Chronos
Chronos is a distributed task scheduler (cf. cron) for the Mesos cluster management system. In this edition of Jepsen , we’ll see how simple network interruptions can permanently disrupt a Chronos+Mesos cluster
1223
epoll: The API that powers the modern internet (2022)
Linux's epoll API solved the C10K problem, enabling fast and afforable Internet services.
1224
Writing high performance F# code
While this post is addressed to F# .NET developers, it introduces much wider concepts starting from hardware architecture to overall .NET runtime and JIT compiler optimizations. It shouldn't be a surprise - optimizing the application performance requires us to understand the relationships between our high level code…
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Running a Minecraft Server and more on a 1960s UNIVAC Computer
18 bit registers, 90kb of memory, ones’ complement, powered by RISC-V.
1228
DNSFS – Store files in others' DNS resolver caches
A while ago I did a blog post about how long DNS resolvers hold results in cache for, using RIPE Atlas probes testing against their default resolvers (in a lot of cases, the DNS cache on their modem/router).
1229
When TCP sockets refuse to die
While working on our Spectrum server , we noticed something weird: the TCP sockets which we thought should have been closed were lingering around. We realized we don't really understand when TCP sockets are supposed to time out!
1230
Making an embedded Linux computer
Designing and soldering a small ARM Linux board with 217 ball BGA package and 0402 passive components