Thanks a lot for your review and for your hints.
David Miller wrote:
From: Sven Eckelmann sven.eckelmann@gmx.de Date: Fri, 16 Jul 2010 16:39:16 +0200
[...]
The kernel has a hamming weight library function which takes advantage of population count instructions on cpus that suport it, and also has a sw version than is faster than what you're doing here, please use it.
The interfaces are called "hweight{8,16,32,64}()" where the number in the name indicates the bit-size of the word the interface operates on.
Correct, the inner loop is a quite straight forward implementation without any kind of optimization. I will change that.
I also notice that this code uses it's own internal buffering scheme with kmalloc()'d buffers, then seperately allocates actual SKB's and copies the data there.
Just use the SKB facilities how they were designed to be used, instead of needlessly inventing new things. Allocate your initial SKB and put the initial forwarding header in it, then when you want to send a copy off, skb_clone() it, and push the other bits you want at the head and/or the tail of the cloned SKB, then simply send it off.
Good catch. That comes from a time when batman-adv was a minimalistic conversation of the userspace proof of concept implementation. This happens for example in vis.c, icmp_socket.c and send.c (just grepping for send_raw_packet is a good way to find those places). But is also happening with batman_if->packet_buff in schedule_own_packet and similar places.
I would leave that to the original author of those functions.
thanks, Sven