3 ms·
Realistically, only processes that are scheduled on sibling hyperthreads, and hyperthreading can be restricted to processes that have the same privilege level,
by saddlerustle 5y ago
Realistically, only processes that are scheduled on sibling hyperthreads, and hyperthreading can be restricted to processes that have the same privilege level, which is done on ChromeOS. The amount of microarchetectural state that sticks around after a context switch is finite and whenever there's a new avenue found like this, usually easily fixed by ucode update and kernel fix.
- corty 5y ago> easily fixed by ucode update and kernel fix Those microcode updates and kernel fixes are anything but easy. They are anything but lightweight. Context switching overhead is a huge contributor to lag and general inefficiency in interactive systems. Every kind of Spectre mitigation increases that overhead. Every further mitigation wrecks more of the performance advantages that caches have historically provided. From a performance, power consumption and efficiency perspective, Spectre is a disaster. Mitigations just move the problem from a security and privacy one to an efficiency and performance one.