x86 PCU
Thor Lancelot Simon <[email protected]>
| Newsgroups | gmane.os.netbsd.ports.x86-64,gmane.os.netbsd.ports.i386 |
|---|---|
| Message-ID | <[email protected]> |
About 3 years ago Matthias Drochner committed changes to use the MI pcu framework for lazy FPU switch on x86. This was quickly backed out by Christos because, evidently, it caused system hangs. I am implementing AESNI support as well as some other code that wants "FPU" registers in the kernel, and I am cringing every time I type in code that manually saves and restores the FPU state at a cost of hundreds of cycles per. So I would love to see PCU working on x86. I can't find much discussion of what was wrong -- aside from the commit message when the code was backed out, saying it had caused hangs. Does anyone remember or know more about this? Would anyone be willing to have another shot at making it go? -- Thor Lancelot Simon [email protected] Cry, the beloved country, for the unborn child that is the inheritor of our fear. -Alan Paton