On Thu, Apr 30, 2015 at 11:13 AM, Umut Tezduyar Lindskog <[email protected]> wrote: > Hi Simon, > > On Wed, Apr 29, 2015 at 5:34 PM, Simon McVittie > <[email protected]> wrote: >> On 29/04/15 15:08, Umut Tezduyar Lindskog wrote: >>> We [1] have noticed that there could be up to %50 performance gain on >>> using sd-bus over gdbus on dbus-daemon. >> ... >>> gdbus.c >>> - g_dbus_proxy_new_for_bus_sync() >>> - 50 x g_dbus_proxy_call_sync() >>> >>> sdbus.c >>> - sd_bus_open_system() >>> - 50 x sd_bus_get_property() >> >> If you want to "compare apples with apples", I suggest using the >> lower-level g_bus_get() and g_dbus_connection_call[_sync]() instead of >> GDBusProxy. The design and priorities of sd-bus and GDBus are not really >> very similar, but GDBusProxy is certainly not the closest equivalent you >> can get. > > Thanks for the tip. I will re-run the measurements with > g_dbus_connection_call_sync(g_bus_get_sync(),...). Just considering > the traffic in the dbus, I do believe we have compared apple to apple. > But if you believe we might get even more performance with raw API > calls, then that is fantastic news!
Unfortunately I didn't get any better result with g_dbus_connection_call_sync. I have updated the link (https://drive.google.com/open?id=1O3FEnpdZ2auisYalKT6qJTiNV9cfDxya_qisbpGj3MQ&authuser=0) with the source code if you would like to double check my work. Umut > >> >> Also, if your application profile is such that (a) D-Bus is a >> significant factor in performance, and (b) sending 50 synchronous D-Bus >> messages per connection is anywhere near realistic, then you are >> probably not using D-Bus the way it is designed to be used. > > Measurement we have done was not about if dbus is the ipc we want or > not. It was about comparing the performances of two libraries. It > wouldn't have been fair to compare sending only 1 message on the dbus > due to the performance penalty of creating a worker thread with gdbus. > But it really didn't matter. 1, 2, 10, 50, in all cases gdbus > (GDBusProxy) couldn't performed as good as sd-bus. > >> >> See also <http://permalink.gmane.org/gmane.comp.freedesktop.dbus/13663>. >> >> -- >> Simon McVittie >> Collabora Ltd. <http://www.collabora.com/> >> >> _______________________________________________ >> systemd-devel mailing list >> [email protected] >> http://lists.freedesktop.org/mailman/listinfo/systemd-devel _______________________________________________ systemd-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/systemd-devel
