4 ms·

Maybe time to redo the ring model with multi core cpu's now the norm. Why one or two CPU cores couldn't be dedicated to the OS aspect and locked out of user-sp

• wtallis 6y ago
  In general, dedicating some cores to userspace and some to kernel would mean sending a lot more data up to L3 for core-to-core communication, and I'm not sure that would be any better than flushing L1d. The exception would be with SMT, but then you're locked into a 1:1 ratio for user and kernel virtual cores, and still have to worry about side channel vulnerabilities.
  • Zenst 6y ago
    That is true, which does somewhat put a whole new perspective upon this, will they flush l2,l3 next! Be nice though to have a proper isolated core or two for the OS, after all - that is exactly what is done for enclave based security and management systems. Though some not all a great track record.
• monocasa 6y ago
  Or more rings. The problem is that we have this idea of running trusted and untrusted code and data in the same context as far as the CPU is concerned. Add more fine grained memory partitions to let the memory hierarchy in on what you're doing. Make Rings 1 & 2 Great Again