Linux Kernel 4.15
TLDR: Linux Kernel 4.15 was officially released in January 2018, introducing significant improvements in hardware compatibility, security, and performance. It addressed critical vulnerabilities like Spectre and Meltdown with mitigations to safeguard processors against speculative execution attacks. Kernel 4.15 also brought updates to energy efficiency and support for modern hardware, making it a key release for distributions like Ubuntu 18.04 LTS.
https://en.wikipedia.org/wiki/Linux_kernel
A major highlight of Linux Kernel 4.15 was its inclusion of security mitigations for Spectre and Meltdown, which affected a wide range of processors. These mitigations improved the kernel's resilience against speculative execution vulnerabilities, ensuring better protection for systems handling sensitive data. Additionally, Kernel 4.15 introduced enhanced support for modern CPUs and GPUs, including compatibility with AMD Radeon Vega graphics and updates to Intel's processor features.
https://www.kernel.org/releases.html
Performance optimizations in Linux Kernel 4.15 included better energy management for mobile devices and improvements to KVM (Kernel-based Virtual Machine) for virtualization workloads. It also added support for RISC-V architecture, reflecting the kernel’s commitment to embracing emerging technologies. By addressing critical vulnerabilities and expanding hardware compatibility, Linux Kernel 4.15 played a pivotal role in advancing the reliability and security of modern Linux distributions.
https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html