CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK (not configurable)

configname: CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK

Linux Kernel Configuration
└─>HAVE_IRQ_EXIT_ON_IRQ_STACK
In linux kernel since version 3.13 (release Date: 2014-01-19)  
Architecture doesn't only execute the irq handler on the irq stack
but also irq_exit(). This way we can process softirqs on this irq
stack instead of switching to a new one when we call __do_softirq()
in the end of an hardirq.
This spares a stack switch and improves cache usage on softirq
processing.