- allow to move long running handlers out of the hard interrupt context,
- avoid complex hardirq -> tasklet/softirq interaction and locking problems by integrating this functionality into the threaded handler code,
- improve debugging of the kernel: faulty handlers no longer take down the entire system,
- allow prioritizing handlers which share a single interrupt line, and
- have the potential to improve the I/O performance by decoupling the various parts of the ISR from each other
In fact, first tests of drivers that have been converted to threaded interrupts have shown considerable performance gains.
Linux subsystem maintainers will use the remaining two months of the 2.6.30 gestation period to implement threaded interrupt support. If all works well, this feature will then be fully available in the unpatched 2.6.31 kernel. Jonathan, we are coming.