Messages in this thread | ![/](/images/icornerl.gif) | | Date | Wed, 24 Nov 2010 21:46:06 +0800 | Subject | Re: [question] NR_IRQS in genirq | From | Haojian Zhuang <> |
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On Wed, Nov 24, 2010 at 9:18 PM, Thomas Gleixner <tglx@linutronix.de> wrote: > On Wed, 24 Nov 2010, Haojian Zhuang wrote: > >> Hi all, >> >> I'm using the latest kernel 2.6.37-rc1. Now I met some issues on genirq. >> >> 1. While SPARSE IRQ is enabled, nr_irqs may be larger than NR_IRQS. >> But the allocated_irqs bitmap (kernel/irq/irqdesc.c) is restricted in >> NR_IRQS. Is it an issue? > > Why can nr_irqs become larger? Is that a theoretical problem or did > you run into this ? > >
Hi Thomas,
My hardware environment is ARM. Each machine description can specify nr_irqs. In my implementation of PXA, NR_IRQS is fixed for SoC internal IRQs. And there's some additional board IRQs, we arrange them between NR_IRQS and nr_irqs. So nr_irqs will be larger than NR_IRQS if board IRQs exists.
We use dynamic board IRQs since each machine has different requirement. And CONFIG_HARDIRQ_SW_RESEND is occasionally, I actually met issue in resend_irqs because of accessing bitmap memory out of bound.
Do you mean that we shouldn't use SPARSE IRQ by this way?
Best Regards Haojian
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