Interrupt noise can be eliminated by eliminating the interrupts themselves using user-space drivers like SPDK and DPDK for storage and networking, but (a) that

Interrupt noise can be eliminated by eliminating the interrupts themselves using user-space drivers like SPDK and DPDK for storage and networking, but (a) that would require a massive change in application architecture, and (b) it wouldn't help non-movable interrupts like softirqs or IPIs for rescheduling and TLB shootdown. Softirqs aren't really interrupts, and they're totally under kernel control, so it might be possible to spread them out across cores or otherwise reduce their signal. Eliminating noise from IPIs for rescheduling and TLB shootdown might require crazy architectural changes to the CPU - for instance an architecturally isolated fast timer which is basically a separate CPU, polls a queue of TLB shootdown requests and a wakeup request flag, and can exit without waking the CPU from a halt. Fuzzing the timer seems like a hack - it doesn't eliminate the information leakage, but just makes it harder to measure. You can eliminate the signal by only reporting the amount of time that passes in user mode, but that results in a clock that can be arbitrarily slower than wall clock time. I suppose you could add a correction factor that's heavily filtered, so the final timer is never off by more than a constant amount, but this would have to be implemented as a new OS timer type with instrumentation in every interrupt handler, and then Javascript would have to be updated to use that new timer.