A door is a "file" descriptor used to describe a procedure in a process and optionally some additional state associated with the procedure. Doors were initially designed as Spring object descriptors used to encapsulate the state and capabilities of C++ objects. A process which obtains a door is free to pass it, along…
If you've ever used the GNU Compiler Collection (GCC) then you've worked with the gcc binary. For those who don't know, gcc is a driver, not a compiler. It runs the compiler/assembler/linker as required and coordinates the input and output between them. Use of the driver is so ubiquitous that everyone calls it the…
Paul Hsieh's 6th generation x86 CPU comparision page including K6, P-II and 6x86MX geared towards the high performance software developer audience
When a service fails to start up enough times in a row, systemd gives up on it. On servers, this isn’t what I want — in general it’s helpful for automated recovery if daemons are restarted indefinitely. As long as you don’t have circular dependencies between services, all your services will eventually come up after…
Using libblkio, QEMU Storage Daemon, and VDUSE
Rust compilation times is an ongoing topic that generates many discussions online1. Most people don’t really care about what exactly takes time when compiling Rust program; they just want it to be faster in general. But sometimes, you can see people pointing fingers at specific culprits, like LLVM or the borrow…
Let me set the right expectations first. This bug I found is actually not that complicated, it's very straightforward once you see what's going on. But I still think the process it took me to uncover this bug could be interesting. It's also kind of interesting that a simple bug stayed undiscovered for so long. I will…
In a previous post, I’ve shown how to use the rayon framework in Rust to automatically parallelize a loop computation across multiple CPU cores.Disappointingly, my benchmarks showed that this only provided a 2x speedup for my workload, on a computer with 8 CPU threads.Worse, the total “user” and “system” times…
When doing systems programming we often need to wait for something to happen. Common examples might be waiting for some data to come through a socket or waiting on a lock. We also often want to wait on any of several conditions to become true. A web server might be handling many sockets at once, waiting for any number…
I recently found that MAME supports running the SGI Indy while looking for ways to test some modifications I was making to the mips code in 9front. After a fair bit of elbow grease cinap and I (but mostly cinap) were able to get the old 9front indy kernel booting and running within mame. I thought I might as well…
The previous iteration of this article was too technical, too long, and contained a lot of controversial points, so I've been thinking for a long time about rewriting it completely, making it accessible to the non-technical folks, and exposing the deeper core issues that still make Linux a questionable match for the…
Resolving PS2SDK Soft Reset Issues
Using a full-featured RPC framework for IPC seems like overkill when the processes run on the same machine. However, if your project anyway exposes RPCs for public APIs or would benefit from a schema-based serialisation layer it makes sense to use only one tool that combines these—also for IPC. Microservices for…
tl;dr : Software shadow stacks could deliver up to 8x faster stack trace capturing in the Go runtime when compared to the frame pointer unwinding that landed in go1.21. This doesn’t mean that this idea should escape from the laboratory right away, but it offers a fun glimpse into a potential future of hardware…
I’m going to start this post off with the obligatory list of links to the previous parts in the series if you’re new here and are interested in seeing the full story: 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , and 9 . This is the tale of how I upgraded my Chumby 8 to run a modern Linux kernel.
For the past week I have been configuring hyprland and using it as my daily driver. Coming from major Desktop Environments like KDE or Gnome, this was definitely quite challanging, specially when implementing features that we take it for granted on these DEs, like screen sharing or screenshot annotating.
A while back I had to deal with a bit-packed format that contained a list of integer values encoded in one of a pre-defined sets of bit widths, where both the allowed bit widths and the signed-ness…
This post is about the AioContext lock removal in QEMU 9.0 (planned for release in 2024), how we got here, and what it means for multi-threa...
A hands-on introduction to database internals. Build an LSM storage engine with SSTables, compaction, WAL recovery, MVCC, and transactions.
With the recent release of OpenBSD 7.5, I decided to run through my personal OpenBSD “installer” for laptop/desktop devices. The project is built off of the dwm tiling window manager and only installs a few basic packages. The last time I updated it was with the release of 7.3, so it’s been due for an minor rework.
If you read my previous article on DOS memory models, you may have dismissed everything I wrote as “legacy cruft from the 1990s that nobody cares about any longer”. It's time to see how any of that carried over through the 16-bit to 64-bit evolution.
I have recently released an open source tool called sotrace . It maps out the .so dependencies for a binary or library, and presents th...
This post guides through decompiling Hyper-V Manager to rebuild it from source, aiming to assess its value for potential open-sourcing. It explores manual and automated decompilation processes, including troubleshooting and enhancing the tool, advocating for community-led improvements to this widely-used but neglected…
Low level software usually has lots of .cc or .rs files. Even lower-level software, like your cryptography library, probably has .S containing assembly, my least favorite language for code review.
This post was made possible through hard work and determination. Do not feel frustrated if this stuff does not click immediately and remember, the source of truth will always be the source code. For us, our source code is raw assembly. That said it’s important you understand these techniques in detail because when…
Almost five years ago I wrote a brief history about .net on non-Windows platforms . I stumbled over that article now and it resurfaced traumatic memories of navigating .net development on Linux and MacOS.
