Re: High CPU usage with sata_nv

[Lee Revell]

On 2/21/07, Matthew Fredrickson <creslin@xxxxxxxxxx> wrote:
> It's a 2.6.18 kernel.  What we're seeing (by means of the interrupt pin
> on another card) is extremely large interrupt latency (measured from
> the time the interrupt pin goes low to the first couple lines of code
> in the IRQ handler to clear it) occasionally, in the order of 500-700
> microseconds.  I figured it was some other driver on the system
> disabling irqs for a long period of time, but it's difficult to trace
> what might be doing that.

Apply the -rt kernel patch and enable the latency tracer, it will tell
you what code path is responsible.

Lee
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