Re: [PATCH 20/62] sparc: irq: Remove IRQF_DISABLED

[Thomas Gleixner]

On Wed, 7 Sep 2011, David Miller wrote:

> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Date: Wed, 7 Sep 2011 19:57:21 +0200 (CEST)
> 
> > On Wed, 7 Sep 2011, David Miller wrote:
> >> From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> >> Date: Wed, 7 Sep 2011 19:33:52 +0200 (CEST)
> >> 
> >> We had big problems when openning thousands of virtual network
> >> devices, each with their own unique IRQ, and pointed all at the same
> >> cpu, and we'd get IRQ stack overflows.
> >> 
> >> See commit c58543c869606532c2382f027d6466f4672ea756
> >> 
> >> So this change to make IRQF_DISABLED a nop has reintroduced this bug.
> > 
> > See commit e58aa3d2d0cc01ad8d6f7f640a0670433f794922
> > 
> > We run ALL interrupt handlers with interrupts disabled for that reason
> > and we even check and yell when an interrupt handler returns with
> > interrupts enabled. That's why IRQF_DISABLED became meaningless.
> 
> Awesome.
> 
> Can I politely ask that a reference to that commit and something like
> your paragraph here explaining things is added to these IRQF_DISABLED
> removal patches?

That's a good idea. I'll let sed loose on the changelogs when I pick
them up.

Thanks,

	tglx
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