Messages in this thread | | | Date | Thu, 01 Mar 2012 14:56:11 +0100 | From | Javier Martinez Canillas <> | Subject | Re: [PATCH 0/10] af_unix: add multicast and filtering features to AF_UNIX |
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On 03/01/2012 01:59 PM, Eric Dumazet wrote: > Le jeudi 01 mars 2012 à 13:50 +0100, Rodrigo Moya a écrit : >> the main problem in D-Bus we are trying to solve is the context >> switches, since right now, there is a daemon, which listens on a UNIX >> socket, and all traffic in the bus goes through it, and then the daemon >> has to route the messages it gets on that socket to the corresponding >> place(s). So, every time someone sends a message to D-Bus, since all >> traffic goes through the daemon, dbus-daemon gets waked-up, which is one >> of the biggest bottlenecks we are trying to fix. >> >> That's why we are thinking about using multicast with socket filters, so >> that the daemon only gets traffic it cares about and thus is not waked >> up and context switches don't happen when not needed. >> >> Using message queues, AFAICS, we would have the same problem, as the >> daemon would create the message queue and would get all traffic, right? >> > > This is why I mentioned extensions.
> > Anyway, if you think multicast sockets is the way to go, then you could > setup a virtual network just to be able to use AF_INET multicast. > > Thats probably doable without kernel patching. >
We could use AF_INET multicast on a local machine but we need some ordering and control flow requirements that are not guaranteed on UDP multicast over IP. That's why we thought to add a new address family AF_MCAST.
To make it a general local multicast solution and not being too specific we added some flags to control its behavior like MCAST_MREQ_DROP_WHEN_FULL to decide to either block the sender or drop the packet when one receiver has its queue full.
Regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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