Re: [PATCH] X86: Change the default value of nr_irqs from 32 to NR_IRQs

Alex Nixon
2008-08-19T23:20:15Z

Yinghai Lu wrote:
> when !CONFIG_HAVE_SPARSE_IRQ, with dyn_array, could allocate irq_desc
> and etc as less as possible.
> when CONFIG_HAVE_SPARESE_IRQ, no actually meaning for nr_irqs.
>
> YH

So I believe the only case this affects is !CONFIG_HAVE_SPARSE_IRQ

The worry is that with CONFIG_HAVE_DYN_ARRAY we may waste memory by
pre-allocating more irq_descs than may be necessary (NR_IRQs vs 32)?

With !CONFIG_HAVE_DYN_ARRAY however, a static array of size NR_IRQS is
allocated instead - so doesn't defaulting nr_irqs back to NR_IRQS just
revert to the old behaviour (with the exception of the irq_descs being
allocated in pre_alloc_dyn_array instead)?

- Alex