Messages in this thread | | | Date | Thu, 01 Mar 2012 20:29:04 +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 08:02 PM, Javier Martinez Canillas wrote: > On Thu, Mar 1, 2012 at 6:59 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote: >> Le 1 mars 2012 08:02, Luiz Augusto von Dentz <luiz.dentz@gmail.com> a écrit : >>> >>> Contrary to someones believes I don't think AF_INET is that fast (e.g. >>> http://scottmoonen.com/2008/04/05/a-performance-comparison-of-af_unix-with-loopback-on-linux/) >>> >> >> Oh you mention a recent zork it seems ;) >> >> Are we speaking of performance problems, apart from scheduler problems >> for D-Bus (each message wakeing all receivers, all receivers read and >> drop message but the target) ? >> > > Hi Eric, > > The only performance problem we are talking about is the scheduling > for D-bus (context switch to the daemon for each message). With today > implementation the receivers only gets messages that were sent to it > but the D-bus daemon has to be wake it up for every message to he can > do the routing. For multicast messages (i.e: D-bus signals) this is > even worse since the daemon has to do a send() for each receiver. > >> I am actually one of the few people working to improve performance on >> both AF_INET and AF_UNIX parts. Just take a look at recent commits. >> >> Right now you can send/receive millions of udp messages per second on >> your linux machine, if you figured out how to avoid process scheduler >> costs. If D-Bus wants more, I highly suggest using shared memory >> instead of passing messages. >> -- > > Yes, I also thought that AF_UNIX would be more efficient than AF_INET > but I was wrong. Yesterday I wrote some tests using our multicast unix > socket, UDP multicast over IP on a single machine and even multicast > using AF_NETLINK sockets and got very similar performance results. > > The only problem is the ordering and control flow requirements for D-bus. >
And the fd passing for out-ouf-band communication used for some D-bus application such as oFono and BlueZ.
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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