From mboxrd@z Thu Jan 1 00:00:00 1970 From: Armin Steinhoff Subject: Re: fast interprocess communication ? Date: Mon, 05 Jul 2010 18:48:49 +0200 Message-ID: <4C320CF1.7080803@steinhoff.de> References: <1273680443.27703.33.camel@gandalf.stny.rr.com> <4BEBB1C8.90606@steinhoff.de> <20100513175842.GN6055@pengutronix.de> <4BED1937.6080907@steinhoff.de> <20100514114625.GA6055@pengutronix.de> <4C2B2BA0.8080108@steinhoff.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-rt-users@vger.kernel.org To: Pradyumna Sampath Return-path: Received: from moutng.kundenserver.de ([212.227.126.186]:55091 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752860Ab0GEQpx (ORCPT ); Mon, 5 Jul 2010 12:45:53 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: Hi Prady, Pradyumna Sampath wrote: > Hi Armin, > > On Wed, Jun 30, 2010 at 1:33 PM, Armin Steinhoff wrote: > > >> what are you using if you need a "real fast" interprocess communication ? >> > > Does the posix mqueue's not fit your need ? The mqueue system is based on the file system and isn't the fastest. The concept of mqueue is OK ... > Have you tried them ? Do > have some kind of numbers about your definition of fast ? > Local message exchange between lokal processes in less than 10us. > For me, the POSIX mqueues seemed to work, though with some initial > trouble which was fixed with a patch to the kernel follow this thread > ( http://lkml.org/lkml/2010/4/2/293 ) , this patch is now queued for > mainline inclusion for 2.6.35. > > There is also a new test suite to measure message queue perf in the > rt-tests. Its called pmqtest. > Interesting ... I will give it a try. I plan do some conceptual work for a UIO based message passing solution. It should be possible to use read and write (triggering uio_event_notify() ) and a UIO device memory to implement a non-copy data exchange. Regards --Armin