Messages in this thread |  | | Subject | 2.5.69 Interrupt Latency | From | Paul Fulghum <> | Date | 07 May 2003 11:12:20 -0500 |
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Starting with kernel version 2.5.69, I am encountering what appears to be increased interrupt latency or spikes in interrupt latency.
I noticed this on two serial drivers that use programmed I/O with FIFOs. On 2.5.68, no problems. On 2.5.69 plenty of underruns. Inspecting the driver tracing, it does not look like lost interrupts.
I see this on 2 different machines (one SMP server and one laptop).
There were changes involving the return type of interrupt handlers (from void to irqreturn_t) in 2.5.69. Could this be related?
Has anyone else seen similar results?
If I can get time, I'll try and hook up a scope to measure the latencies precisely. I want to check to see if this is a known problems before doing so.
-- Paul Fulghum, paulkf@microgate.com Microgate Corporation, http://www.microgate.com
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