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by londons_explore 928 days ago
I don't think AMD does microcode updates for performance issues do they? I thought it was strictly correctness or security issues.

If the vendor won't patch it, then a workaround is the next best thing. There shouldn't be many - that's why all copying code is in just a handful of functions.
2 comments
p3n1s 928 days ago
A significant performance degradation due to normal use of the instruction (FSRM) not otherwise documented is a correctness problem. Especially considering that the workaround is to avoid using the CPU feature in many cases. People pay for this CPU feature now they need kernel tooling to warn them when they fallback to some slower workaround because of an alignment issue way up the stack.
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prirun 928 days ago
If AMD has a performance issue and doesn't fix it, AMD should pay the negative publicity costs rather than kernel and library authors adding exceptions. IMHO.
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