Linux creator Linus Torvalds on Monday released version 3.9 of the Linux kernel, and particularly intriguing among numerous new features and improvements is support for laptops running Google's Chrome OS.
"Whatever the reason, this week has been very quiet, which makes me much more comfortable doing the final 3.9 release, so I guess the last -rc8 ended up working," wrote Torvalds in the release announcement early Monday.
1. Chrome OS support
Certainly most intriguing from a hardware perspective is that kernel 3.9 adds "complete support for all the devices present in the Chrome laptops sold by many companies," as explained in the changelog on KernelNewbies.org.
2. Faster Performance
Also new in Linux 3.9 is the ability to use a fast device such as a solid-state drive (SSD) as a cache for a slower device such as a rotating disk. Faster performance under heavy loads can be one result.
3. KVM support in ARM
Now offered within the ARM architecture port is support for the KVM virtualization system, bringing virtualization capabilities to the Linux ARM ecosystem.
4. Improved power efficiency
An Intel PowerClamp driver in this latest kernel release, meanwhile, "performs synchronized idle injection across all online CPUs. The goal is to maintain a given package level C-state ratio," the changelog explains. "Compared to other throttling methods already exist in the kernel, such as ACPI PAD (taking CPUs offline) and clock modulation, this is often more efficient in terms of performance per watt."
5. Two new architectures
Last but not least, the 3.9 release brings the Linux kernel port to the ARC700 processor family (750D and 770D) from Synopsys as well as the Meta ATP (Meta 1) and HTP (Meta 2) processor cores from Imagination.
The ARC700 family is highly configurable and power efficient, and can be found embedded in SoCs deployed in TV set-top boxes and digital media players, for example. Meta cores, meanwhile, can typically be found in many digital radios.