On Sat, 20 Jun 2020, Taylor R Campbell wrote: > Here's a straw proposal for an MI API to allow a kthread to use any > vector or floating-point unit on the CPU -- call it the `FPU' for > brevity.
Description elided. > Thoughts? I think this is sort of a half-measure since it restricts coprocessor usage to a few threads. If you want to say, implement the kenrel memcopy using vector registers (the way sparc64 does) this doesn't help and may end up getting in the way. I'd do something simpler such as adding a MI routine to allocate or activate a temporary or permanent register save area that can be used by kernel threads. Then, if you want, in the coprocessor trap handler, if you want, if you are in kernel state you can check whether a kernel save area has been allocated and panic if not. Eduardo
