* Mark_H_Johnson@raytheon.com <Mark_H_Johnson@raytheon.com> wrote:

> LONG NETWORK LATENCIES
> ======================
> 
> In about 25 minutes of heavy testing, I had two latency traces with
> /proc/sys/kernel/preempt_max_latency set to 700. They had the same start /
> end location with the long delay as follows:
>   730 us, entries: 361
>   ...
>   started at rtl8139_poll+0x3c/0x160
>   ended at   rtl8139_poll+0x100/0x160

regarding this particular latency, could you try the attached patch
ontop of -Q5? It turns the ->poll() loop into separate, individually
preemptable iterations instead of one batch of processing. In theory
this should result in latency being lower regardless of the
netdev_max_backlog value.

	Ingo