Re: prioritize PCI traffic ?

[Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>]

Soeren Sonnenburg wrote:
> Dear all,
> 
> is it possible to explicitly tell the kernel to prioritize PCI traffic
> for a number of cards in pci slots x,y,z ?
> 
> I am asking as severe ide traffic causes lost frames when watching TV
> using 2 DVB cards + vdr... This is simply due to the fact that the PCI
> bus is saturated...

How do you know that the bus is saturated?
Are you streaming data to/from the ide hard disks/CDROM?
Do you have DMAs 'ON' for the hard disks?
Is everything just fine if there are no IDE traffic?
Are you running 2.6 kernel with preempt 'ON'?
Are all hardware on the same IRQ line? (shared interrupts)

> So, is any prioritizing of the PCI bus possible ?

The drivers + application indirectly can control priority on the
bus.  Just reduce the priority of the application that uses IDE and
see if adjusting nice values of applications can change the scenario.

--Vaidy

> Best
> Soeren
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