It is now available the version Linux 6.15-rc2, just one week after the official closure of the change integration window and the first release candidateThis second kernel release candidate comes with a variety of early fixes that have been collected over the past few days, as part of the usual Linux kernel development cycle.
Linus Torvalds, as usual, was in charge of announcing this new version and commented that, despite the fact that the merge window was longer than usual, For now everything looks pretty normal.. The number of commits and the changes made remain within typical statistical margins, with no single aspect standing out excessively at this early stage of the release.
Linux 6.15-rc2 introduces improvements to graphics drivers: Intel and AMD
One of the most notable points in this version has to do with the graphics drivers. On the AMD side, the AMDGPU driver has added support for the discrete video memory management through cgroups, a functionality called DMEMThis integration now allows VRAM usage to be limited by specific processes through group control mechanisms.
In addition to DMEM support, the AMD driver has also received adjustments to eDP management, fixes for VRAM pinning in P2P-enabled import environments, as well as fixes to workload profiles and IP discovery within the rendering system.
As for Intel graphics, The Xe driver has included an important fix for the flickering issues observed in Meteor Lake graphics. In particular, the behavior of read-only L3 cache lines associated with geometry streams has been corrected. This change aims to eliminate the annoying visible flickering that some users had reported on systems with this architecture.
It has also been added new device identifier 0xE211 corresponding to the future “Battlemage” architecture, in anticipation of its official launch, and multiple small fixes have been applied to other graphics subcomponents such as the AMDKFD (for computing) and the Intel IVPU NPU driver, improving support for suspend and resume operations.
Updates and cleanup to Spectre RSB mitigations
Another of the pillars of this version are Improvements in mitigation measures for Spectre RSB (Return Stack Buffer), a vulnerability present in Intel and AMD processors. The work has been led primarily by Red Hat developers, who have spent several months perfecting the kernel's handling of these measures.
Among the main corrections is the adjustment in the call a indirect_branch_prediction_barrier(), as well as the elimination of filling the RSB both in virtual machine exits (VMEXIT) and in context changes if use is being made of eIBRS and Retpolines.
In addition to the code, New specific documentation has been included This document clearly summarizes current mitigation strategies, separating attack scenarios by processor type and architecture. This document is intended to serve as a reference for developers who may need to address future vulnerabilities in this area.
General maintenance and early testing
As with every early release candidate, Linux 6.15-rc2 also incorporates minor tweaks distributed throughout the code, including areas such as the core, file systems, network, documentation, and specific architectures. As stated, about 25% This week's patches are dedicated to self-tests, which is unusual but not out of the ordinary during this phase.
In parallel, some users and developers have already begun their own tests on this version of the kernel. In one of these tests, carried out on a Lenovo ThinkPad T14s Gen6 equipped with processor AMD Ryzen AI 7 PRO 360 (Zen 5, Strix Point), more than 60 benchmarks were evaluated between Linux 6.14 and the current state of 6.15. The results show no notable variations, except for some improvements in synthetic microbenchmarks such as Stress-NG. In real-world tests, most metrics remained within the usual margin of error.
These early findings reinforce the idea that no serious regressions have been introduced at this early stage, and that kernel support for the new AMD platform is already quite mature.
This second release candidate for Linux 6.15 offers an initial look at how this development cycle is evolving, with relevant technical improvements in key areas such as security and GPU handling. Although there's still a long way to go until its stable release, scheduled for the end of May, current developments show a steady progression, oriented toward bug fixes and the consolidation of new features.