kernel

diff -u: Speeding Up the Un-Speed-Up-able

Sometimes kernel developers can work in parallel for years without realizing it. It's one of the inefficiencies of a distributed system that tends to work out as a benefit when you have enough contributors to be able to spare the extra labor—it's sort of a "with enough eyeballs, all bugs are shallow" kind of thing.

diff -u: Intel Design Flaw Fallout

For weeks, the world's been talking about severe Intel design flaws affecting many CPUs and forcing operating systems to look for sometimes costly workarounds. Linux patches for these issues are in a state of ongoing development. Security is always the first priority, at the expense of any other feature. Next would probably be the general speed of a running system for the average user. After that, the developers might begin piecing together any features that had been pulled as part of the initial security fix.

diff -u: Linus Posting Habits

A look into how, when and why Linus posts to the kernel mailing list. Linus Torvalds sometimes is criticized for bombastically cursing out kernel developers. He does do this, but it's not his default behavior, and I think the real nature of when and how he posts to the mailing list is interesting. For example, he stayed out of the whole discussion of how to replace the BitKeeper revision control system for a long time, letting various projects guess frustratingly at his desires, before he finally took a break from Linux development to design and implement git.

diff -u: Automated Bug Reporting

Bug reports are good. Anyone with a reproducible crash should submit a bug report on the linux-kernel mailing list. The developers will appreciate it, and you'll be helping make Linux better!

ZFS for Linux

Presenting the Solaris ZFS filesystem, as implemented in Linux FUSE, native kernel modules and the Antergos Linux installer.

diff -u: Adding Encryption to printk()

When is security not security? When it guards against the wrong people or against things that never happen. A useless security measure is just another batch of code that might contain an exploitable bug. So the Linux developers always want to make sure a security patch is genuinely useful before pulling it in.

Custom Embedded Linux Distributions

The proliferation of inexpensive IoT boards means the time has come to gain control not only of applications but also the entire software platform. So, how do you build a custom distribution with cross-compiled applications targeted for a specific purpose? As Michael J. Hammel explains here, it's not as hard as you might think.

diff -u: in-Kernel DRM Support

A look at what's new in kernel development. Welcome to the new diff -u! We're experimenting with a shorter, more frequent, single-subject format for this feature, which also may evolve over time. Let us know what you think in the comments below.

NVMe over Fabrics Support Coming to the Linux 4.8 Kernel

The Flash Memory Summit recently wrapped up its conferences in Santa Clara, California, and only one type of Flash technology stole the show: NVMe over Fabrics (NVMeF). From the many presentations and company announcements, it was obvious NVMeF was the topic that most interested the attendees.

diff -u: What's New in Kernel Development

Sometimes it's necessary to change function semantics inside the kernel, and then find and update all users of that function to match the new semantics. Such changes can result in huge patches going into the source tree, affecting hundreds of files.

diff -u: What's New in Kernel Development

The OOM killer is a tough nut to crack. How can a system recover when it's violently thrashing and out of RAM? Once upon a time, you'd just have to reboot. And today, that still might be necessary, but less so, because the OOM killer attempts to identify and stop the process that seems to be causing the hangup. The problem is, it may not choose the right process every time.

diff -u: What's New in Kernel Development

There's an ongoing impulse among a diversity of developers to be able to compile some or all of the Linux kernel as a library, so that a piece of software could use kernel services and APIs while running under a different kernel entirely, or a different operating system.

diff -u: What's New in Kernel Development

Linux capabilities are one of the more fluid and less defined regions of kernel development. Linus Torvalds typically has no trouble violating POSIX standards if he sees a better way of doing something. In the case of filesystem capabilities, however, there's no standard to violate.

diff -u: What's New in Kernel Development

The NMI (non-masking interrupt) system in Linux has been a notorious patchwork for a long time, and Andy Lutomirski recently decided to try to clean it up. NMIs occur when something's wrong with the hardware underlying a running system.