Il giorno gio, 16/09/2010 alle 17.23 +0100, Al Johnson ha scritto: > kdbus is proof-of-concept at the moment, the idea being to reduce the number > of context switches needed for each dbus message. One synthetic benchmark > shows a 3x speed increase on the n900 but speedup in real world applications > seems much more modest. > > http://alban.apinc.org/blog/2010/09/15/d-bus-in-the-kernel-faster/
Some days ago I've tried to port this patch to the Openmoko kernel, after applying it to the SHR 2.6.32 kernel (patches at [1]), I got these results (in average): dbus-ping-pong test: Ping dbus-daemon (s) kdbus (s) speedup 500 ping 3.33 2.13 36.2% 5000 ping 32.59 26.09 19.9% 50000 ping 313.56 176.35 43.8% Adrien Bustany’s ipc-performances tool with 60000 random 10 char strings: dbus-daemon query (s) kdbus query (s) speedup 102.75 74.71 27.29% So, the results are quite good, but the code is actually buggy... In fact when enabling it for the system dbus session (which our FSO-based phone mostly uses for exchanging data between apps), some applications doesn't work as expected (Messages, Contacts...), since the kdbus "socket" actually just supports only dbus requests with few parameters (< 8kB) and these apps really have greater requests... By the way, waiting for kdbus upstream fixes (I've already contacted its author, who is now aware of the bugs I found), I guess that this system could give us a nice speedup when with many core applications with very few sources changes. Comments? PS: More informations about my issues have been filled as comments of of the alban's blog article linked above. [1] http://pastebin.com/3kfnUqzb _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community