Hardware interrupts are crucial part of I/O communication of Linux systems. Hardware topologies are very complex nowadays and minimizing interrupt processing latencies needs overview of the whole system, e.g. position of hardware on bus, loads of particular parts of hardware hierarchy from processors to NUMA nodes or special affinity requirements of drivers. This task is solved (or is tried to solve) either by manual pinning or by automated tools. Petr Holášek will thoroughly describe the irqbalance tool at the presentation. He will show its current interrupt distribution algorithm, possible improvements of it and prove or refute why this task cannot be done by kernel itself now.