tree cd995419a3eb84d3e18e92ff205af86a7a4ed66d
parent e2f4d06545ec1f29b0e838ee34cbf3500ea5b9a4
author Mike Travis <travis@sgi.com> 1231655046 -0800
committer Ingo Molnar <mingo@elte.hu> 1231697615 +0100

irq: allocate irq_desc_ptrs array based on nr_irqs

Impact: allocate irq_desc_ptrs in preparation for making it variable-sized.

This addresses this memory usage bump when NR_CPUS bumped from 128 to 4096:

    34816   +229376    264192  +658%  irq_desc_ptrs(.data.read_mostly)

The patch is split into two parts, the first simply allocates the
irq_desc_ptrs array.  Then next will deal with making it variable.
This is only when CONFIG_SPARSE_IRQS=y.

Signed-off-by: Mike Travis <travis@sgi.com>