51 points by hasheddan 1 day ago | 2 comments
Neywiny 10 hours ago
Interesting. I was just thinking about this because of another post on floating point. I'm wondering if I can disable the fpu every so often and turn it on only if code needs it and it raises an exception.
glitchc 3 hours ago
It's unclear why one would ever need to do this. Is it for power savings? What other use-cases would benefit from turning the FPU off between instructions?
russdill 2 hours ago
There is overhead, and applications that don't use the FPU avoid that overhead. https://www.netbsd.org/docs/kernel/lazyfpu.html
bobmcnamara 4 hours ago
Yes, you could turn it off every context switch.
summa_tech 5 hours ago
Zephyr support lazy FPU context switches. So the downside from enabling FPU sharing is fairly limited.