I've got a customer that wants to get access to the PTP[1] registers of a NIC from user space. The customer suggests that context switches introduce too much l

I've got a customer that wants to get access to the PTP[1] registers of a NIC from user space. The customer suggests that context switches introduce too much latency and indeterminism (pre systems integration phase - lots of software from different teams ends up running on the final platform) to introduce a reference monitor (capability-based microkernel or otherwise) given known techniques on modern hardware. I'm afraid I can't share the specifics because I don't have them, but I trust the source. I will grant that this case is an outlier, but this customer use-case is real enough to drive development dollars. It may not be the norm, but precision timing access appears to be very useful in some hard real-time contexts given current hw/sw realities. [1] https://en.wikipedia.org/wiki/Precision_Time_Protocol https://en.wikipedia.org/wiki/Precision_Time_Protocol