Kernel is the core of any Linux distribution and it is the kernel that gave name to all these systems. Linux kernel contains a lot of configuration options and you can get very different kernel images from the same source code. In addition, there are a lot of patches all over the worlld that are not included to the main development tree but that can be interesting for certain groups of users. So it is no wonder that different Linux distributions even if based on the same version of source code from Linux Torvalds provide users with quite different kernels,

In ROSA, we use the kernel variations initially created by the MIB (Mandriva International Backports) group and named nrj and nrjQL. What do these names actually mean and what features stand behind them? Let's listen to Nicolò Costanza who builds kernels for ROSA Desktop distributions:

Technically speaking, with the "NRJ" configs the CPU and RCU are configured with full Preemption enabled (CPU Preemption, RCU Preempt tree) and in full Boost mode. The "QL" mode also adds the CK1 patchset including BFQ disk I/O scheduler and BFS CPU load scheduler. One should also mention the presence of UKSM for a better memory manager and TOI for better suspension and hibernate functionality, each designed with desktop system performance and responsiveness in mind. So we really try to do everything to obtain a feeling close to realtime kernel from user point of view.

What are the roots of the name?

We looked for a small nickname (2 to 4 chars) for our kernel variation. Several names were proposed and at the end the most of MIB people liked NRJ, Amongst the another proposals there was kernel-viagra, but this was rejected:) The NRJ word actually stands for ENERGY and should underly that the kernel is acting for a PC like an energetic drink do for a human being, like a RED BULL, but we could not adopt that name or another registered trademark. In the case when PC is very stressed by different tasks but a slow response is unacceptable, NRJ try to offer the missing ENERGY to your PC. With NRJ the PC is more responsible in a multitasking experience.

So here is the short description of the kernel used in ROSA.

Actually we have several variations of the kernel - Nico always builds at least vanilla, nrj-laptop and nrj-desktop editions. The process of Nico's work can be always tracked at Nico's repository in ABF. Finally, more details about history of nrjQL patches in ROSA can be found in MIB forum.

ABF nicco.png
Nico's repository in ABF - almost every minor kernel update is built and tested for ROSA