Message-id: <553DFA09.9000605@samsung.com>
Date: Mon, 27 Apr 2015 10:57:45 +0200
From: Lukasz Skalski <l.skalski@samsung.com>
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To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Havoc Pennington <hp@pobox.com>
Cc: Andy Lutomirski <luto@amacapital.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
        Tom Gundersen <teg@jklm.no>, Jiri Kosina <jkosina@suse.cz>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Daniel Mack <daniel@zonque.org>,
        David Herrmann <dh.herrmann@gmail.com>,
        Djalal Harouni <tixxdz@opendz.org>
Subject: Re: [GIT PULL] kdbus for 4.1-rc1
References: <20150413190350.GA9485@kroah.com> <20150423130548.GA4253@kroah.com>
 <20150423163616.GA10874@kroah.com>
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 <20150423171640.GA11227@kroah.com> <553A4A2F.5090406@samsung.com>
 <CAEntwhEJHioQmg250gcjB5GRtWO_khgH3yQrPufi5ssWNFavRQ@mail.gmail.com>
 <553A547A.1060505@samsung.com> <20150424192546.GA13543@kroah.com>
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On 04/24/2015 09:25 PM, Greg Kroah-Hartman wrote:
> On Fri, Apr 24, 2015 at 04:34:34PM +0200, Lukasz Skalski wrote:
>> On 04/24/2015 04:19 PM, Havoc Pennington wrote:
>>> On Fri, Apr 24, 2015 at 9:50 AM, Lukasz Skalski <l.skalski@samsung.com> wrote:
>>>> - client: http://fpaste.org/215156/
>>>>
>>>
>>> Cool - it might also be interesting to try this without blocking round
>>> trips, i.e. send requests as quickly as you can, and collect replies
>>> asynchronously. That's how people ideally use dbus. It should
>>> certainly reduce the total benchmark time, but just wondering if this
>>> usage increases or decreases the delta between userspace daemon and
>>> kdbus.
>>
>> No problem - I'll prepare also asynchronous version.
> 
> That would be great to see as well.  Many thanks for doing this work.

As it was proposed by Havoc and Greg I've created simple benchmark for
asynchronous calls:

- server: http://fpaste.org/215157/ (the same as in the previous test)
- client: http://fpaste.org/215724/ (asynchronous version)

For asynchronous version of client I had to decrease number of calls to
128 (for synchronous version it was x20000 calls), otherwise we can
exceed the maximum number of pending replies per connection.

The test results are following:

+--------------+--------------------+--------------------+
|              |    Elapsed time    |    Elapsed time    |
| Message size |  GLIB WITH NATIVE  | GLIB + DBUS-DAEMON |
|   [bytes]    |    KDBUS SUPPORT*  |                    |
+--------------+--------------------+--------------------+
|              |    1) 0.018639 s   |    1) 0.029947 s   |
|     1000     |    2) 0.017045 s   |    2) 0.032812 s   |
|              |    3) 0.017490 s   |    3) 0.029971 s   |
|              |    4) 0.018001 s   |    4) 0.026485 s   |
+--------------+--------------------+--------------------+
|              |    3) 0.019898 s   |    3) 0.040914 s   |
|    10000     |    3) 0.022187 s   |    3) 0.033604 s   |
|              |    3) 0.020854 s   |    3) 0.037616 s   |
|              |    3) 0.020020 s   |    3) 0.033772 s   |
+--------------+--------------------+--------------------+
*all tests performed without using memfd mechanism.

And as I wrote in my previous mail, kdbus transport for GLib is not
finished yet and there are still some places for improvements, so please
do not treat these test results as final).

> 
> greg k-h
> 

Cheers,
-- 
Lukasz Skalski
Samsung R&D Institute Poland
Samsung Electronics
l.skalski@samsung.com
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