[LAD] cpu spikes

Len Ovens len at ovenwerks.net
Mon Jan 25 15:18:33 UTC 2016

On Mon, 25 Jan 2016, Fokke de Jong wrote:

>   16:          0          0          0          0   IO-APIC   16-fasteoi   madifx

Is this your audio interface on irq 16? If so why is it sharing an IRQ? 
Move it to a different slot maybe? If this is a PCI card and there is only 
one slot, I would suggest a different motherboard with more PCI slots. My 
personal experience with sharing IRQs has never been good even using rtirq 
to separate things out. One thing to try is in BIOS there is sometimes a 
setting that tells bios to set irqs or not. I have found setting it to not 
lets the kernel set it and the kernel does a better job. Also, some bios 
have a part where you can fix a PCI card to a irq, that may help.

I am sure some will say that if rtirq doesn't help there is a bad 
driver... OK. The thing to remember is that PCs are not built for low 
latency but high throughput. Most people find that high throughput makes 
for a "snappy" user experience. Low latency to most HW designers means 

Len Ovens

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