However, there is a big difference in CPU-load when running iperf3,
especially with multiple threads:

WITH the CODE saying it disables IRQ mitigation:
$ iperf3 -c 192.168.3.1
[  5] 0.00-10.00  sec  10.3 GBytes  8.83 Gbits/sec
CPU: iperf3 22.5% ksoftirqd 16.6%

$ iperf3 -c 192.168.3.1 -P4
[SUM]   0.00-10.00  sec  9.36 GBytes  8.04 Gbits/sec
perf3: 19.3% ksoftirqd 96.7%


WITHOUT the CODE saying it disabled IRQ mitigation:
[  5]   0.00-10.00  sec  10.3 GBytes  8.87 Gbits/sec
CPU: perf3 19.7% ksoftirqd 12.5%

$ iperf3 -c 192.168.3.1 -P4
[SUM]   0.00-10.00  sec  10.3 GBytes  8.81 Gbits/sec
CPU: iperf3 22.0% ksoftirqd 46.5%

Thanks for doing this performance testing.

My undestanding from the first email by Michal is that the behavior with the
ESHUTOWN is actually harmless and has been seen in the driver already for
the RTL8153.

So, my suggestion is I drop this part of the patch-series and remove the
IRQ-mitigation code that says it disables the IRQ mitigation as performance
is higher without that code.

Agreed.

	Andrew