Linus Torvalds recently announced the release of Linux Kernel 5.8, and he seems delighted with it. He has pointed it out as the most significant release of all time. To developers, this new kernel comes with an addition of 800,000 new code lines and more than 14,000 changed files. To the average user, you might not see many eye-candy changes, as seen in the earlier releases.
Overall, the Linux Kernel 5.8 releases include a bunch of driver support, optimizations, processor improvements, and a variety of security enhancements. In the Linux Kernel mailing lists, Linus Torvalds wrote, “So I didn’t expect this, but 5.8 looks to be one of our biggest releases of all time.”
Given the release timeline for Linux 5.8, it may be available for testing in distributions like Ubuntu 20.10 and Fedora 33 soon. Let’s take a look at some of the features you can expect in Linux Kernel 5.8.
Linux Kernel 5.8: Key Features & Changes
Considering Linux Kernel 5.8 is one of the biggest releases, you should expect quite a tonne of technical changes and improvements. We will focus on some of the features which have an impact on the overall end-user.
1. AMD Energy Driver
If your computer runs a Zen/Zen2 AMD CPU, then it’s great news to know that the new Linux Kernel 5.8 release supports the AMD Energy Driver.
In case you don’t know what this means, users running Zen/Zen2 AMD CPU will now be able to get energy reports on per-socket/per-core. It is more useful to persons interested in knowing their CPU power consumption.
2. AMD Renoir CPU temperature monitoring
Another feature you should expect with Linux Kernel 5.8 is CPU temperature monitoring for PCs running Renoir processors.
On the earlier Kernel releases, the Linux k10temp driver for Zen/Zen2 CPU core required for temperature reporting doesn’t work. With the addition of PCI IDs in Linux 5.8, Renoir CPU temperature monitoring will now be possible on Linux systems.
3. AMD Renoir ACP audio support
Linux kernel 5.8 also features a new hardware support for the sound subsystem with the AMD Renoir (Ryzen 4000 mobile) Audio Co-Processor (ACP) support.
4. AMDGPU Trusted Memory Zone (TMZ) Support
It is a new feature that comes with Linux 5.8. It targets open-source graphics drivers that work with the device’s graphic hardware enabling encryption for portions of the video memory.
Even though Trusted Memory Zone (TMZ) support dates back to the original Vega graphics processors, it is the first time that we will see this feature in Linux. The AMD Trusted Memory Zone (TMZ) offers secure buffer object support on Linux by hindering the contents of TMZ’ed pages from being read by the CPU, a non-GPU client.
5. Kernel Concurrency Sanitizer (KCSAN)
The Kernel Concurrency Sanitizer feature, which adds up to ‘4K + Lines of code’ to Linux 5.8, is a dynamic race detector necessary for detecting any arising flaws in the Kernel code. To detect kernel races, KCSAN relies heavily on compile-time instrumentation and applies a watchpoint-based sampling approach.
6. Boost support in the CPPC CPUFreq driver
The ACPI-defined Collaborative Processor Performance Control (CPPC) CPUFreq driver is a feature presented by Linux Kernel 5.8 to enable “boost” for optimal CPU level performance.
Collaborative Processor Performance Control ACPI specification is a normalized mechanism for depicting abstract performance scales. It is a method for having the option to request higher/lower performance levels and estimating per-CPU performance.
7. Open Source Adreno 405 / 640 / 650 GPU support
With Linux 5.8 release, users can expect updates on the open-source MSM drivers (Freedreno). That brings forth the support for Qualcomm’s Adreno 405, 640, and 650 GPUs.
Adreno 405 is quite old and has been in the market since the days of snapdragon 415/615/616/617. Adreno 640/650 is still quite relevant for the current-generation hardware. Adreno 640 enables the provision of graphics for Snapdragon 855/855+, while Adreno 650 is focused on Snapdragon 865.
8. Shadow Call Stack and Branch Target Identification for ARM64
Some of the ARM architectural changes supported by Linux Kernel 5.8 revolve around two security features: Branch Target Identification and Shadow Call Stack.
Branch Target Identification (BTI) support as a significant aspect of the ARMv8.5 specification. Branch Target Identification marks legitimate targets of indirect branches. The CPU will trap an instruction in a secured page that is attempting to perform an indirect branch to an instruction other than a stamped BTI.
Shadow Call Stack is a compiler-level element when working with LLVM/Clang. Shadow Call Stack is intended to prevent against return address overwrites.
9. More exFAT driver improvements
Linux Kernel 5.7 also included an exFAT driver with its release, but Samsung has sent several improvements, optimizations, and fixes for it.
10. Thunderbolt ARM (i.e. USB 4.0) support
With Linux Kernel 5.8, you should expect Thunderbolt support for non-x86 systems and ARM support. Additionally, Linux 5.8 provides Thunderbolt support for Intel Tiger Lake and several USB improvements and updates.
Other Features in Linux Kernel 5.8
Some of the additional features you should expect in Linux Kernel 5.8 include:
Improved DAX support
If you like speeding up your system with Intel’s Optane memory, the Improved DAX support will allow direct access to files by the persistent memory without the need to use the page cache.
What are your thoughts about Linux Kernel 5.8? Is it an exciting release, given that it is the biggest release of all time? Feel free to share your thoughts and any other information with our readers below.
