On 2/23/21 12:05 PM, Catalin Marinas wrote: >> I totally agree on this point. In the case of runtime switching we might need >> the rethink completely the strategy and depends a lot on what we want to >> allow >> and what not. For the kernel I imagine we will need to expose something in >> sysfs >> that affects all the cores and then maybe stop_machine() to propagate it to >> all >> the cores. Do you think having some of the cores running in sync mode and >> some >> in async is a viable solution? > stop_machine() is an option indeed. I think it's still possible to run > some cores in async while others in sync but the static key here would > only be toggled when no async CPUs are left. >
In such a case we might need to track the state based on cpuid() and have a mask that tells us when cpus are all sync. Not as expensive as stop_machine() but still requires a valid use case to be introduced according to me. -- Regards, Vincenzo
