Re: Attempted summary of "RT patch acceptance" thread

["Paul E. McKenney" <paulmck@us.ibm.com>]

On Wed, Jun 08, 2005 at 12:51:05PM -0400, Karim Yaghmour wrote:
> 
> Paul,
> 
> I've finished reading your summary and I must say that it's excellent.
> I don't remember ever reading a non-partisan comparison of this level
> on the issue of real-time and Linux. Thanks for writing _and_ having
> the guts to post it :)

Thank you for the kind words!  But who needs guts when you have
senility?  ;-)

> There is only one issue I would like to further highlight.
> 
> Note: None of the following should be in any way controversial, I'm
> just providing further background.

;-)  ;-)  ;-)

> Paul E. McKenney wrote:
> > the corresponding approach's strengths and weaknesses.  I do not address
> > "strength of community", even though this may well be the decisive factor.
> 
> Indeed what you state here is entirely true. While Adeos and RTAI
> development has been very active for quite a few years now, it must
> be said that this development has largely gone unnoticed to LKML
> participants -- as was obvious by the amount of surprise caused by
> the realization of the existence of key Adeos and RTAI features.
> 
> Part of this is historical. 10 years ago, Linux's state was such
> that those who were interested in doing rt with it realized that
> it wasn't about to become rt-capable any time soon. Hence, they
> "went away" and did their own little thing. They had their mailing
> lists, their own flame-wars, their own conferences, and there was
> very little common shared with the mainstream LKML community.
> 
> In fact, for a very long time, most kernel developers I spoke to
> about real-time would refer back to a single project, RTLinux. To
> this day, actually, if you look in the MAINTAINERS file, it still
> says:
> > RTLINUX  REALTIME  LINUX
> > P:      Victor Yodaiken
> > M:      yodaiken@fsmlabs.com
> > L:      rtl@rtlinux.org
> > W:      www.rtlinux.org
> > S:      Maintained
> Yet, the days where RTLinux was _the_ real-time Linux extension
> are long gone and www.rtlinux.org has been a redirect to a .com
> site for quite some time now -- I've suggested in the past that
> this entry be replaced by RTAI, but I was told that neither should
> in fact be in there, which is fair-enough, but nothing came of
> this suggestion and the entry is still in the maintainers file.
> 
> This state of things remained until May 2002 when I picked up on
> a post by Andrea to point out a "few" problems the RTAI community
> saw with the RTLinux project. The ensuing thread was remarkably
> intense -- not for the faint of heart. Here's the root of it if
> you're ever interested in reading a huge flame-fest:
> http://marc.theaimsgroup.com/?l=linux-kernel&m=102227589127072&w=2
> While that discussion did serve to put RTAI on the map for some
> developers, it also highlighted problems with the RTAI project
> that needed to be solved.
> 
> Part of the issues was the patent problem, and that was solved
> with the introduction of Adeos. However, with this and other
> problems solved, the RTAI developers went back the way they came
> from: to their own separate mailing lists.
> 
> In the past few years, though, a new bread of real-time developers
> have become interested in making Linux fit for real-time
> applications. Unlike the previous generation, though, these folks
> have concentrated their efforts on working within the framework
> already agreed upon by existing kernel developers: the LKML. And
> in that, they have achieved a level of awareness amongst the kernel
> crowd that I think RTAI and Adeos have not yet reached.
> 
> I've tried to remedy to this situation as best I can, by pointing
> out what was obvious to me when appropriate. However, it must be
> said that I haven't been actively involved with either Adeos or
> RTAI in quite some time. So while I did play a part in the
> history of both projects, there are others that are in a much
> better position than I am to present to the LKML the work done
> by the RTAI and Adeos communities.
> 
> In essence, therefore, what I have to say is this:
> - To those who are actively involved in the development of RTAI
> and Adeos, now is the time to drop the historical tendency of
> acting as an entirely separate community and to start sharing
> your work on the LKML.
> - To those who are actively involved in finding solutions to the
> real-time issues in Linux, do not be fooled by the apparent lack
> of activity in the Adeos or RTAI projects, they are both very
> active and warrant consideration.
> 
> As you correctly state, "strength of community" is likely a decisive
> factor. What is important here is not to confuse "apparent" strength
> of community -- or lack thereof -- with "actual" strength of
> community -- or lack thereof.

All good points!  I added a few sentences encouraging realtime folks to
participate in LKML discussions.

						Thanx, Paul

> Thanks again for a great piece.
> 
> Karim Yaghmour
> -- 
> Author, Speaker, Developer, Consultant
> Pushing Embedded and Real-Time Linux Systems Beyond the Limits
> http://www.opersys.com || karim@opersys.com || 1-866-677-4546
>