Experimental Physics and
Industrial Control System

I have an embedded Linux system based on the ZynQ processor. I have the FPGA configured to generate a hardware interrupt whenever data is ready to be read. The frequency of the interrupts depends on the integration time of the measurement, and should be settable from seconds to around one millisecond. This is all within an EPICS IOC running under ARM Linux, in a Debian 10 system. What I observe is that the maximum frequency I can use is 100Hz, which is the Linux system clock tick frequency. Presumably there is a lock somewhere inhibiting interrupts except at tick time. I tried rebuilding the kernel with the PREEMPT-RT patch enabled, but it seems not to make a difference. I am definitely not a kernel expert; does anyone know what I'm missing?

Thanks,

Pete.