Re: [PATCH net-next] net: ti: icssg_prueth: Add SW TX / RX Coalescing based on hrtimers

[Andrew Lunn]

> I did some benchmarking today with,
> 	1. Default driver (without any IRQ coalescing enabled)
> 	2. IRQ Coalescing (With this patch)
> 	3. Default IRQ Coalescing (Suggested by you in the above patch)
> 
> I have pasted the full logs at [1].
> 
> Below are the final numbers,
> 
> ==============================================================
> Method                  | Tput_TX | CPU_TX | Tput_RX | CPU_RX |
> ==============================================================
> Default Driver           943 Mbps    31%      517 Mbps  38%   |
> IRQ Coalescing (Patch)   943 Mbps    28%      518 Mbps  25%   |
> Default IRQ Coalescing   942 Mbps    32%      521 Mbps  25%   |
> ==============================================================
> 
> I see that the performance number is more or less same for all three
> methods only the CPU load seems to be varying. The IRQ coalescing patch
> (using hrtimer) seems to improve the cpu load by 3-4% in TX and 13% in
> RX. Whereas the default method that you have suggested doesn't give any
> improvemnet in tx however cpu load improves in RX with the same amount
> as method 2.
> 
> Please let me know if this patch is OK to you based on the benchmarking?

It is good to include benchmark results in patches which claim to
improve performance. Please add the default and the patch version
results to the commit message.

The numbers show your more complex version does bring benefits, so it
is O.K. to use it. I just wounder how many other drivers would benefit
from a one line change.

	Andrew