As anticipated, the AMD PerfOpt feature has been selected for inclusion in the Linux 7.4 kernel. Previous benchmarks conducted by Phoronix have demonstrated that this update provides a notable performance increase for AMD integrated graphics, with specific benefits observed in artificial intelligence tasks.
The core function of AMD PerfOpt is to allow integrated graphics processing units (iGPUs) to bypass the IOMMU when accessing system memory directly. This feature is enabled by default for systems utilizing the AMDGPU kernel graphics driver on Radeon integrated graphics hardware.
Performance testing indicates that AMD PerfOpt can enhance AI and large language model (LLM) performance on Radeon iGPUs by approximately 18% to 23%. Additionally, the update has been shown to boost performance for previous-generation Ryzen APUs in AI scenarios when running Linux 7.4.
Users operating on Linux 7.4 or later can verify that PerfOpt is active with the AMDGPU driver by checking the dmesg kernel output for the "PerfOpt" string. The integration of this feature coincided with the merge of IOMMU support, which also included various other AMD IOMMU fixes and clean-ups.
Beyond the AMD-specific updates, the Linux 7.4 kernel now includes Broadcom BCM2712 IOMMU support for display and multimedia devices on the Raspberry Pi 5. Microsoft also contributed a new para-virtualized IOMMU driver designed for use with Hyper-V.
Sources: Phoronix.