IRQ assignment on my IBM X24

ollie lho ollie at sis.com.tw
Mon Apr 7 20:17:00 CEST 2003


On Mon, 2003-04-07 at 16:42, Karl Hammar wrote:
> 
> You can go into your laptops bios and reassign them if you don't like
> that setup, I had the same setting in my tpx20.
> 
> Is there anyone who knows if that setup is bad or not? Does it do any
> difference?
> 

Theoretically, this will give you larger interrupt latency. When the 
kernel is handling some specific IRQ line, it disable further interrupts
on that line (but enable all other lines). If there are other devices
sharing the same line, their interrupts can not be served by the kernel
until the first one is completed. On the other hand, if a device is on
the other IRQ line, the kernel can service the interrupt by entering 
another level of interrupt context. (BTW, this is the case in 2.4.x 
kernel, I am not sure if it is true for 2.5.x.)

-- 
ollie lho <ollie at sis.com.tw>




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