[Cerowrt-devel] eBPF filters for traffic classification?

David Lang david at lang.hm
Thu Dec 11 19:50:31 EST 2014

In part, I was thinking that this sort of thing could make experimenting with 
codel or HTB tweaks much easier. If the classification logic could be written to 
be compiled into eBPF filters, then changing the classification would be just 
loading a new module. And since it's compiled and loaded into the kernel, I'm 
hoping that the performance would be on the same order as C code (even though 
it's interpreted by the eBPF engine), so it wouldn't have the large performance 
hit that we have with the current throttling code for example.

David Lang

On Thu, 11 Dec 2014, Dave Taht wrote:

> oh the bpf stuff and jit work is extremely interesting. There is a
> llvm compiler for it too, now.
> nftables is also interesting but hard to wrap my head around and
> expressing things in it seems only slightly less hard that just
> adopting bpf directly.
> On Thu, Dec 11, 2014 at 4:28 PM, David Lang <david at lang.hm> wrote:
>> http://lwn.net/SubscriberLink/625224/2edd6566c16cf76d/
>> A new capability is being added to the 3.19 kernel that allows writing BPF
>> programs that run in the kernel that can do things like classifying traffic.
>> Right now all this can do is to store information to be retrieved by
>> userspace, but I wonder if it would be useful to use something like this for
>> traffic classification for queue selection, traffic throttling, etc?

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