RE: [RFC PATCH 00/30] Kernel NET policy

Liang, Kan
2016-07-19T01:49:47Z

>
> > Also of course it would be fundamentally less efficient than kernel
> > code doing that, just because of the additional context switches
> > needed.
>
> Synchronizing or configuring any kind of queues already requires rtnl_mutex.
> I didn't test it but acquiring rtnl mutex in inet_recvmsg is unlikely to fly
> performance wise and

Yes, rtnl will bring some overheads. But the configuration is one time thing for
application or socket. It only happens on receiving first packet.
Unless the application/socket only transmit few packets, the overhead
could be ignored. If they only transmit few packets, why they care about
performance?

> might even be very dangerous under DoS attacks (like
> I see in 24/30).
>
Patch 29/30 tries to prevent such case.

Thanks,
Kan