Francois Romieu wrote:

Philip Craig [off-list ref] :
[...]

quoted

This patch caused a drop in throughput from 178 Mbits/sec to 135 Mbits/sec
on an Intel XScale IXP465.

Which distribution of packet sizes ?

Just using iperf with the default options, MTU 1500,
forwarding between 2 PCs with the board in the middle.

quoted

It seems like there is some confusion about what the align parameter
here means. It was originally an offset from an aligned address so that
the IP header aligned, and this patch changes it to the alignment of the
ethernet header. But align is still set to NET_IP_ALIGN for some chips.

Yes, I should have distinguished both in the first place.

Can you describe which chipset from realtek the board is using (lspci -vxx) ?

# lspci -vxx
00:0c.0 Ethernet controller: Realtek Semiconductor Co., Ltd.: Unknown device 8169 (rev 10)
        Subsystem: Realtek Semiconductor Co., Ltd.: Unknown device 8169
        Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 26
        I/O ports at 1000 [size=256]
        Memory at 48061000 (32-bit, non-prefetchable) [size=256]
        Expansion ROM at 48000000 [disabled] [size=128K]
        Capabilities: [dc] Power Management version 2
00: ec 10 69 81 57 01 b0 02 10 00 00 02 08 00 00 00
10: 01 10 00 00 00 10 06 48 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 ec 10 69 81
30: 00 00 00 00 dc 00 00 00 00 00 00 00 1a 01 20 40

00:0d.0 Ethernet controller: Realtek Semiconductor Co., Ltd.: Unknown device 8169 (rev 10)
        Subsystem: Realtek Semiconductor Co., Ltd.: Unknown device 8169
        Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 26
        I/O ports at 1400 [size=256]
        Memory at 48061100 (32-bit, non-prefetchable) [size=256]
        Expansion ROM at 48020000 [disabled] [size=128K]
        Capabilities: [dc] Power Management version 2
00: ec 10 69 81 57 01 b0 02 10 00 00 02 08 00 00 00
10: 01 14 00 00 00 11 06 48 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 ec 10 69 81
30: 00 00 00 00 dc 00 00 00 00 00 00 00 1a 01 20 40