Re: [PATCH net-next 3/4] r8152: Add irq mitigation for RTL8157/9

[Andrew Lunn <andrew@lunn.ch>]

> 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