Stories by Jake Edge

Embedded developers keep watch on kernel bloat

Embedded Linux is getting a lot of attention these days. A new mailing list, linux-embedded-archived here-has been set up, with discussions and patches already being posted. In addition, Paul Gortmaker and David Woodhouse have volunteered to be the "embedded maintainers" for the kernel to help coordinate the embedded Linux community. They graciously agreed to a joint email interview to shed some light on their new roles.

Kernel space: Using the firmware loader for static data

Some device drivers need firmware to load into the hardware at initialization time. The kernel firmware loader interface exists to support that functionality, but it requires help from user space which may not be available in all environments. David Woodhouse has proposed a patch that would eliminate that requirement so that more drivers can use the firmware loader rather than craft their own solution.

Kernel space: Merging drivers early

Drivers tend to be a world unto themselves, with bugs only affecting a subset-often a tiny subset-of kernel users. Until a driver gets merged into the kernel though, anyone wishing to test it, or help clean it up, has to jump through some hoops. To try and help reduce those barriers, Linus Torvalds and others have been advocating early merging of drivers; getting them into the kernel and incrementally improving them from there.

Kernel space: The Linux trace toolkit's next generation

Instrumenting a running kernel for debugging or profiling is on the wish list of many administrators and developers. Advocates of OpenSolaris like to point to DTrace as a feature that Linux lacks, though SystemTap has started to close that gap. The Linux Trace Toolkit next generation (LTTng) takes a different approach and was recently submitted for inclusion in the kernel (in two patches: architecture independent and architecture dependent).

Should security modules be dynamically loadable?

The ever-contentious Linux Security Modules (LSM) API is being debated once again on linux-kernel, not its removal, which Linus Torvalds came down firmly against, but whether it should allow security modules to be loaded dynamically. As part of 2.6.24, Torvalds merged a patch to convert LSM into a static interface, but has indicated a willingness to revert it. The key sticking point is whether there are real security modules that require the ability to be runtime-loaded.