Starting the kdbus discussions

[Kay Sievers]

On Fri, Jan 17, 2014 at 2:27 PM, Lukasz Skalski
<l.skalski at partner.samsung.com> wrote:
> On 01/16/2014 06:28 PM, Lennart Poettering wrote:
>>
>>
>> Anyway, if you care about performance measurements I certainly welcome
>> any work on that!
>
> As I mentioned yesterday I've prepared simple benchmark for my glib
> port with native kdbus support. Below you can find results for first
> working version (latest published patchset you can find here [1] -
> below tests are based on not published yet new version my glib port
> with support for protocol version 2).
>
> ===============
> = Description =
> ===============
>
> In order to perform tests of glib with kdbus native support I've
> created two programs: gdbus_server and gdbus_client. The first of
> them acts as a server, registers itself on the bus under well-known
> name and waits for calls to its objects and methods. The second one
> (client) makes calls and records periods of time between moment of
> preparing of a call to the moment of receiving an answer.
> The measurement is made by performing one thousand of calls and
> computing a sum of duration of every call (for different sizes of
> message payload: 4kB, 8kB, 16kB, 32kB, 64kB, 128kB, 256kB, 512kB
> and 1MB). The client program returns total time of performed calls
> after successful execution.
>
> Simple test applications you can find here [2]
>
> ===============
> = Environment =
> ===============
>
> Host: VirtualBox with Fedora 20 (3.12.5-302.fc20.x86_64)
> All tests was performed in systemd-nspawn container (more info
> here [3]).
>
> kdbus module: last commit 1ab20f6f5
> systemd:      last commit c4e6e2425 (systemd-nspawn container and host)
> glib:         last commit 8bc63b0ef (+kdbus patches for native support)
>
> ===========
> = Results =
> ===========
>
> (all results for PAYLOAD_VEC item)
>
> +--------------+--------------------+--------------------+
> |              |    Elapsed time    |    Elapsed time    |
> | Message size |  GLIB WITH KDBUS   | GLIB + DBUS_DAEMON |
> |              |      SUPPORT       |                    |
> +--------------+--------------------+--------------------+
> | 1000 x 4kB   |     1.351737 s     |     1.870417 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 8kB   |     1.349266 s     |     1.857693 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 16kB  |     1.383427 s     |     2.219304 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 32kB  |     1.358608 s     |     2.542795 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 64kB  |     1.878409 s     |     3.062035 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 128kB |     2.265555 s     |     4.043454 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 256kB |     3.112191 s     |     6.657750 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 512kB |     3.383699 s     |    11.400224 s     |
> +--------------+--------------------+--------------------+
> | 1000 x 1MB   |     4.703610 s     |    19.041988 s     |
> +--------------+--------------------+--------------------+

You see anyting interesting when you run the tests in:
  perf record ...
And look at the results with:
  perf report
?

Can you try the test below on the same box to have something to
compare to the above numbers?

$ ./test-bus-kernel-benchmark chart
SIZE    COPY    MEMFD
1    34000    23970
2    39420    24110
4    38840    23290
8    38070    22970
16    37540    23350
32    39000    23690
64    39130    23910
128    39560    23880
256    39640    24060
512    39500    24120
1024    39520    24080
2048    39140    23900
4096    38600    24110
8192    37990    23020
16384    36700    21220
32768    34320    18950
65536    30280    15540
131072    24300    11260
262144    9390    7470
524288    4510    4380
1048576    2080    2330
2097152    910    1230
4194304    390    600

(ThinkPad T430s, Fedora 20)

Thanks,
Kay