[Unit] Description=Setup special irq affinity Before=sysinit.target After=local-fs.target DefaultDependencies=no [Service] Type=oneshot ExecStart=/bin/true ExecStartPost=-/bin/sh -c 'for i in `cat /proc/interrupts | grep usb | cut -d ":" -f 1`; do echo "4-7" > /proc/irq/$i/smp_affinity_list; done' [Install] WantedBy=sysinit.target