Linus Torvalds released version 4.16 of the Linux Kernel on Sunday, April 1st, nine weeks after the previous version. After the rather eventful 4.15 cycle, which included the loss of the Linux Kernel Mailing List for several days and the fallout from the Meltdown and Spectre bugs, 4.16 has been mercifully smooth.
Not all smooth, though. There was a big bump in the amount of patches in RC7 that nearly derailed Sunday’s release. However, looking into it, Torvalds noted that the abnormal number of submissions may have been due to the fact that during the RC5 and 6 cycles there had been almost no patches regarding networking. This meant there was a backlog of “2.5 weeks worth of networking stuff, and that makes rc7 look artificially bigger. That’s my story, and I’m sticking to it.“ Torvalds said.
Getting back to Meltdown and Spectre, the dust kicked up by both bugs still hasn’t completely settled. Quite a few patches were included to try and ameliorate some of their effects. Both 64-bit ARM and IBM z s390 architectures get patches that mitigate possible exploits. Meanwhile, access to /dev/mem is now more restrictive and the code that keeps x86 architectures safe has been cleaned up and optimized.
In more productive news, the VirtualBox Guest driver was merged into the mainline kernel. This means that the VirtualBox VM should work better on Linux from now on. Vaguely related, Jailhouse, a partitioning Hypervisor developed by Siemens, is now also supported in the mainline kernel. Jailhouse is different to other hypervisors in that it can be loaded and configured by a normal Linux system.
Other stuff to look forward to in Linux kernel 4.16
- The AMD GPU DC display code has been improved so as to incorporate better multi-display support. This means that the highest display rate will be used when synchronizing several monitors. The new code also mitigates underflow/corruption problems which manifest as flickering ghosts when elements are moved on the desktop.
- Operations for in-kernel filesystems will probably become faster thanks to a patch that optimizes the update of inode data and metadata. In some cases, the speed registered in read bandwidth increased to more than 200 percent.
- There have been updates to the open source Risc V ISA, which was merged in 4.15. However, there are no device drivers yet.
- Some new devices that are now supported in the mainline kernel include the Orange Pi R1, NVIDIA’s Tegra TX2, and the second generation “One by Wacom” tablets.
As usual, you can find out more by checking out the writeups at Kernel Newbies and Phoronix.
Learn more about Linux through the free “Introduction to Linux” course from The Linux Foundation and edX.
