The latest blog posts to take off on Hacker News. 498 posts.
Most CPU architectures in use today have an instruction called popcount , short for “population count”. Here’s what it does: it counts the number of set bits in a machine word. For example (assuming 8-bit words for simplicity), popcount(00100110) is 3 and popcount(01100000) is 2 .
This is a post about performance. Most of the time when worrying about the performance of a piece of code the overwhelming advice should be (with apologies to Brendan Gregg) don’t worry about it, yet. However there is one area where I counsel developers to think about the performance implications of a design, and that…
2019-09-05: YugaByte’s blog post states YugaByte DB “passes Jepsen tests”. We feel obligated to state that YugaByte DB’s Jepsen test suite does not pass, though it may in the future. Race conditions in YugaByte DB’s schema system can cause correctness errors. For example, inserting rows into a freshly-created table…
An in-depth analysis of the journey of a Spectre fix into the upstream LTS kernels that left its users with nothing more than a false sense of security.
The urge to replace the mainframe has reinvented the mainframe and its problems.
Compatibility of FreeBSD on a Lenovo Thinkpad T480, notes and fixes (HiDPI, Trackpad, camera, etc).
Learn how Linux/FFmpeg C partial codebase is organized to be extensible and act as if it were meant to have “polymorphism”. Specifically, we’re going to briefly explore how Linux …
It's no surprise that modern deep-learning libraries have production-level, highly-optimized implementations of most operations. But just what is the black magic that these libraries use that we mere mortals don't? What exactly does one do to "optimize" or accelerate neural networks operations?
This article is intended to help C & C++ programmers understand the essentials of what the linker does. I've explained this to a number of colleagues over the years, so I decided it was time to write it down so that it's more widely available (and so that I don't have to explain it again). [Updated March 2009 to…
The lectures assume no prior knowledge of the Paxos consensus algorithm or of TLA+, the language in which the specifications are written. In fact, the lectures constitute a crash course on TLA+. If you're interested just in the algorithm, you will probably find the specs annoying and will try to read only the…
[Discuss this article and read other’s comments on the subject on this thread on Hacker News.] The three fundamental building blocks of computers, CPU, I/O and RAM can come under pressure due to co…
Posted by Ian Beer, Project ZeroProject Zero’s mission is to make 0-day hard. We often work...
Running processes in isolated network namespaces
How to get the most of Rust while keeping your code portable
We’re pleased to announce that Microsoft is supporting the addition of Microsoft’s exFAT technology to the Linux kernel.
Users spend a large proportion of their online time on mobile devices, and a significant fraction of the rest is users on untethered laptop computers.
Barring divine intervention, Windows 10 Enterprise LTSC 2019 ( formerly LTSB ) may be the least bad option:
Get a closer look at how we investigated errors originating from scheduled jobs, and how we stumbled upon "the tyranny of the clock."
Aleksey Shipilёv, JVM/Performance Geek, Shout out at Twitter: @shipilev Questions, comments, suggestions: aleksey@shipilev.net
After languishing through the CPU dark-ages (read: Intel trying real hard to keep people on 4 cores so they could charge an arm and a leg for more), the last two years has seen a vertible tsunami of advances in CPU technologies. AMD's introduction of an 8-core CPU (the 1700X) began the rat-race and with both AMD and…
Posted by Natalie Silvanovich, Project ZeroCVE-2019-8646 is a somewhat unusual vulnerability I re...
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A vision of an OS that recognizes that any user activity and most of the system activities are nothing but queries, which ought to be treated uniformly and implemented efficiently once and for all; database as a file system; A paper submitted to MacHack'95
Trying to determine exactly where asynchronous interrupts are delivered on Intel CPUs.
It’s been 3 months since I first wrote about our efforts to scale Git to extremely large projects and teams with an effort we called “Git Virtual File System”. As a reminder, GVFS, together with a set of enhancements to Git, enables Git to scale to VERY large repos by virtualizing both the .git folder […]
In a post a few months back I said it’s a popular myth that const is helpful for enabling compiler optimisations in C and C++ . I figured I should explain that one, especially because I used to believe it was obviously true, myself. I’ll start off with some theory and artificial examples, then I’ll do some experiments…
