Messages in this thread | | | Date | Wed, 19 Dec 2012 02:22:11 -0500 | From | Paul Thompson <> | Subject | SPARSE_IRQ |
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Hi;
Perhaps Im being an idiot, but it looks to me like the menu-item for SPARSE_IRQ (under General setup -> IRQ subsystem) depends solely on MAY_HAVE_SPARSE_IRQ, but I only see *one* user for that in the kernel now, the SuperH arch (arch/sh/Kconfig). It looks like everyone else explicitly sets SPARSE_IRQ. However the menu-items description implies it is a more generic option... It seems like this menu item used to appear, in a forced on state, then this condition made it disapear, leaving a blank IRQ subsystem menu for me. I was trying to work around that, but now, I am not sure exactly what is supposed to be going on here...
Paul
(from kernel/irq/Kconfig) config SPARSE_IRQ bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ ---help---
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.
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