Subject: Re: Subject: [PATCH 1/2] x86: get back 15 vectors

From: Yinghai Lu <[email-masked]>
Date: Mon, 04 Jan 2010 10:40:47 -0800

On 01/04/2010 08:18 AM, Eric W. Biederman wrote:
> Yinghai Lu <[email-masked]> writes:
> 
> This patch is wrong.
> 
>> between FIRST_EXTERNAL_VECTOR (0x20) and FIRST_DEVICE_VECTOR (0x41)
>>
>> for 0x20 and 0x2f, we are safe be used_vectors will prevent it to use used one.
> 
> We can not use any of 0x20 - 0x2f for ioapic irqs.  We need the entire
> priority level to ensure that the irq move cleanup ipi is of a lower
> priority.
> 
>> also try to reuse 0x30 to 0x3f after smp_affinity for irq[0,15] is changed to other cpu.
> 
> There may be a point with 0x30 to 0x3f as I recall when those irqs come through a legacy
> pic we need to reserve those vectors on all cpus.

ok, I see.

any reason that we can not use 0x40?

Thanks

Yinghai