Re: [RFC] bpf: Suggestion on bpf syscall interface

[Alexei Starovoitov <ast@plumgrid.com>]

On 3/29/15 8:13 PM, He Kuang wrote:
>
> By using current bpf syscalls, we should keep the program which
> attaches bpf programs running background, use it or some other
> processes communicate with it to adjust maps parameters, like
> sample rate for sys_write.

You can do all of the above by passing fds between processes. I still
don't see a need for sysfs.

> In current implementation, we have to use a large and relative
> heavy daemon to deal with loading, configuration, adjusting and
> unloading works together.

This daemon is actually small and simple.
Just take a look how Daniel did for tc:
http://patchwork.ozlabs.org/patch/456387/
In that example 3 programs are sharing maps and single bpf_agent
monitors maps. Note that tc loaded programs and exited while
agent keeps running. Very straightforward.