[lkml]   [2003]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subject2.5.69 Interrupt Latency
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,
Microgate Corporation,

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:35    [W:0.886 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site