Messages in this thread | | | Subject | Re: Kernel hooks just to get rid of copy_[to/from]_user() and syscall overhead? | From | Gianni Tedesco <> | Date | 10 Jan 2003 15:31:06 +0000 |
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On Fri, 2003-01-10 at 14:45, Mihnea Balta wrote: > Hi, > > I have to implement a system which grabs udp packets off a gigabit connection, > take some basic action based on what they contain, repack their data with a > custom protocol header and send them through a gigabit ethernet interface on > broadcast. > > I know how to do this in userspace, but I need to know if doing everyting in > the kernel would show a considerable speed improvement due to removing > syscall and memory copy overhead. The system will be quite stressed, having > to deal with around 15-20000 packets/second.
mmap() packet socket interface eliminates the need for system calls when traffic is coming in at a high rate. The kernel -> user copy is also eliminated, but its just replaced with a kernel -> kernel copy :P
You could perhaps also use linux socket filters to minimize the number of packets you need to evaluate...
Check out this sample code: http://www.scaramanga.co.uk/code-fu/lincap.c
HTH
-- // Gianni Tedesco (gianni at scaramanga dot co dot uk) lynx --source www.scaramanga.co.uk/gianni-at-ecsc.asc | gpg --import 8646BE7D: 6D9F 2287 870E A2C9 8F60 3A3C 91B5 7669 8646 BE7D [unhandled content-type:application/pgp-signature] | |