Subject: Re: Network throughput (localhost)
From: Bernd Petrovitsch <bernd@firmix.at>
To: Aki Niimura <akineko@gmail.com>
Cc: linux-kernel@vger.kernel.org
In-Reply-To: <59f1f0cb0903130025k31cc2c9fud865dd776534c2bd@mail.gmail.com>
References: <59f1f0cb0903130025k31cc2c9fud865dd776534c2bd@mail.gmail.com>
Content-Type: text/plain
Organization: Firmix Software GmbH
Date: Fri, 13 Mar 2009 11:18:55 +0100
Message-Id: <1236939535.25161.17.camel@spike.firmix.at>
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 2203
Lines: 52

On Fri, 2009-03-13 at 00:25 -0700, Aki Niimura wrote:
[...]
> I developed a Python program, which tries to take advantage of
> available Multi CPU resources.
> Two programs (Server and Client) are running in separate processes
> communicating each other using Socket IPC.
> The performance I'm getting is somewhat in line with my expectation
> under Solaris/x86 but significantly slower
> under Linux (CentOS 5) even both use the identical hardware.
> 
> My investigation revealed that the performance is bottlenecked by the
> communication (Socket to localhost).
> 
> So, I wrote much simpler program (socket server and socket client) to
> measure the network throughput.
> What I found was that the network throughput on both platforms
> (Solaris/x86 and CentOS Linux) are almost
> identical if packets are going out but the network throughput of
> Solaris/x86 is almost twice (up to three times)
> the throughput Linux can deliver if the packets are destined to localhost.
> 
> I know that Solaris treats packets destined to localhost differently.
> 
> Because of this, my program is slower (than one process) under Linux
> (and is practically useless).
> (I see meaningful performance gain under Solaris/x86, though)
> I haven't tried any other Linux distributions.
> Is there any Linux distribution known for better localhost network throughput?
> Is there any way to improve the localhost throughput under Linux (CentOS)?
> 
> Of course, some people would point out that other types of IPC (such
> as shared memory) are better choices
> for the communication between closely coupled multi-processing
> program. Unfortunately, there are
> reasons that my program needs to use Socket.
> 
> Any suggestions will be greatly appreciated.

Have you tried AF_UNIX sockets?

	Bernd
-- 
Firmix Software GmbH                   http://www.firmix.at/
mobil: +43 664 4416156                 fax: +43 1 7890849-55
          Embedded Linux Development and Services


--
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/