Linus Torvalds this week announced the release of the Linux kernel version 4.1, which will also form the basis of the next long term stable (LTS) kernel release. Linux 4.1 was also the first kernel release to include contributions from more than 1,500 developers (1,539 to be exact) — with about 270 submitting their first ever patch, according to LWN Editor Jonathan Corbet. The previous record for the most developer participation on a release was set last June with Linux 3.15, which boasted 1,492 developers submitting patches. (See his full 4.1 release report.)
Despite the record level of participation, Torvalds had a “quiet” week after the final release candidate, rc8.
“I’m not sure if it was quiet because there really were no problems (knock wood), or if people decided to be considerate of my vacation, but whatever the reason, I appreciate it. It’s not like the 4.1 release cycle was particularly painful, and let’s hope that the extra week of letting it sit makes for a great release. Which wouldn’t be a bad thing, considering that 4.1 will also be a LTS release,” Torvalds wrote on the Linux kernel mailing list.
“Anyway, since rc8 we’ve had truly small changes, mainly some final driver fixups (HDA sound, drm, scsi target, crypto) and a couple of small misc fixes. The appended shortlog is probably one of the shortest ones ever. I’m not complaining.”
This release comes with significant improvements. Here is a selection of improvements which affect the enterprise as well as consumer space.
Improvements for Chromebooks
Linus is a Chromebook user, as we know from his Google+ posts, and so am I. For those Chromebook users who install their own distros on these devices, there are massive improvements with this release. Patches submitted by Dmitry Torokhov improve the support for touchpads and touchscreen on Google’s Chromebook Pixel 2, when running a Linux distro instead of Chrome OS.
Talking about laptops, the 4.1 release also brings improvements for Dell and Toshiba laptops. Thanks to the patches by Darren Hart from Intel, the release will enable users of the supported Dell laptops to use keyboard back-lighting. Toshiba laptop users will also notice many improvements including USB sleep charging support and improved back-lighting.
Improved Btrfs support
Btrfs is the future of the Linux file system and it’s already the default FS on many distros including openSUSE. It continues to get better with each release. Chris Mason, the principal author of Btrfs, who now works for Facebook, sent patches which fixes a regression from 4.0 “where conversion between different raid levels would sometimes bail out without converting.” Thanks to his patches, 4.1 improves performance on massive Btrfs file systems of about 20 terabytes or more. It also fixes ENOSPC aborts when deleting huge files (3 TB or more).
From Android with Love: ext4 encryption
Google is among the leading contributors to the Linux kernel and they have Theodore Ts’o, the former CTO of the Linux Foundation, and the creator of ext4 file system, which is used heavily at Google. Google finally implemented ext4 encryption in Android, which is aimed at the upcoming release of Android M. It has now made its way to the mainline Linux kernel. Ts’o sent pull requests for 4.1 which brings file system encryption to ext4 on Linux.
Graphical improvements and Intel chips
Linux 4.1 brings out-of-the-box acceleration for Nvidia’s GTX 570 series graphic cards. In addition, it brings significant performance improvements for Intel’s low powered Atom chips.
The release has reportedly improved battery life and performance on select Intel chips. These can be attributed to the tweaks made to the drivers for Atom chips – more specifically Bay Trail, Cherry Trail and Skylake SoCs.
Bits and bytes
Customers using software RAID on Linux will notice improvement thanks to the patches submitted by Neil Brown. In his pull request Brown explained, “A few have performance impacts which should mostly be positive, but RAID5 (in particular) can be very workload sensitive …. we’ll have to wait and see.”
I have only skimmed the cream of what’s exciting in the latest Linux kernel. I would advise keeping a eye on the Kernel Newbies page as they add more info to the 4.1 page.