The help associated with SPARSE_IRQ says:
Sparse irq numbering is useful for distro kernels that want
to define a high CONFIG_NR_CPUS value but still want to have
low kernel memory footprint on smaller machines.
( Sparse irqs can also be beneficial on NUMA boxes, as they spread
out the interrupt descriptors in a more NUMA-friendly way. )
If you don't know what to do here, say N.
Is it really usefull/necessary to select it for all powerpc as done by
arch/powerpc/Kconfig ?
Shouldn't we at least make if conditionnal to SMP ?
Christophe
