The Long Wait: Boot Times and AMD Processors
For the past 18 months, many users of older AMD processors—specifically those built on the “zen 1” and “zen 2” architectures—have faced the frustrating experience of prolonged boot times. The delays could stretch from a few seconds to several minutes, leading users to question whether they accidentally stirred up an ancient computing curse during their last system update.
A Kernel Fix for the Ages
Thankfully, a significant fix has made its way into the Linux kernel 6.13-rc1 release. This solution addresses the boot issues that originally stemmed from a kernel modification made back in June 2023. It’s like a knight returning from a long quest, ready to banish the boot-time delay demons that have plagued servers powered by AMD EPYC processors.
The Technical Breakdown
The issue at hand was linked to CPU microcode update handling, specifically a missing step in the boot process. Older AMD systems require the patch buffer mapping to be flushed from the translation lookaside buffer (TLB)—a detail that apparently slipped through the cracks, much like a penny in a couch. The new fix implements this necessary TLB flush for affected AMD Ryzen and EPYC systems, effectively eliminating those “unnecessary and unnatural delays” in boot time.
Not only will this fix be included in the upcoming Linux 6.13 kernel, but plans are also in the works to back-port the solution to stable kernel versions, ensuring that even those clinging to their older zen architectures can benefit from quicker startups.
