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Tue, 22 Aug 2006

Zero-copy networking.

I've implemented initial zero-copy sending support based on network allocator. Here is tcpdump dump: 

tcpdump: listening on lo, link-type EN10MB (Ethernet), capture size 96 bytes
20:55:13.709761 IP0 [|ip]
	0x0000:  0000 0000 0000 0000 0000 0000 0800       ..............
There is a problem though - I mmap data for only CPU0-bound allocator, but it is possible that allocation happens on different CPU, so there will be incorrect data (that is what you see above - there should not be any zeroes).
This problem should be fixed by proper protocol between userspace sniffer and network allocator (currently what is being used can not be called protocol at all). Since I introduced ->ioctl() method anyway I will use appropriate commands there.

/devel/networking/zcs :: Link / Comments ()