How to generate default_smp_affinity file in /proc/irq virtual directory
 

I am using RedHat MRG on a standalone intel PC that has 8 cpus. It has 2 Quad cores. I am trying to force some specific persistent tuning on it so that the OS and IRQs are all on one CPU socket and then I can run my Application on the other CPU socket (4 CPUs) using the taskset command. I have been reading up on this mainly at <http://kbase.redhat.com/faq/docs/DOC-15596#2_Add_the_appropriate_isolcpus_kernel_boot_command_line_parameter> and having some success. But, I have one IRQ that is not active until my application runs that I want to force it to be on CPU 4. And so I believe I can do this by setting /proc/irq/default_smp_affinity to 10. But, I do not have such a file on my system. How can I create this file at boot time properly? Or is there some other method to solve this problem somebody can suggest. All suggestions welcome.

Thanks for any help on this.