More DTrace envy [LWN.net]

More DTrace envy

Posted Jul 3, 2008 12:45 UTC (Thu) by mjw (subscriber, #16740)
In reply to: More DTrace envy by paulj
Parent article: More DTrace envy

No, I am not complaining about which free software licenses Sun choose. I am happy they
release software under a free license. And I hope they will do more of it. However pretending
that legal uncertainty and explicitly distributing source code under GPL-incompatible terms
aren't a (the) major issue, while claiming to want wider adoption of that code base under
GNU/Linux and suggesting it isn't adopted because of NIH is just silly.

I have worked on several occasions with Sun, and I have spoken on several occasions to Danese
and other people at Sun about free software, CDDL, GPL,  communities and legal issues to know
they really understand that the legal uncertainty around the CDDL is the only issue preventing
adoption of the technology on a wider scale in GNU/Linux.

As GNU Classpath maintainer I have been more than impressed with how Sun handled Java the last
couple of years. The GNU and Sun java communities happily work together now (after 15 years of
separation) exactly because Sun made sure to do the right thing legally to ensure the widest
possible adoption and cooperation with the existing libre-java communities. I have only praise
for how that was handled. And that is really the reason I am so disappointed about the mess
they made with dtrace/cddl preventing cooperation and adoption on a wider scale, while
claiming to want cooperation that is impossible to achieve because of these messy legal
issues.

to post comments

More DTrace envy

Posted Jul 3, 2008 14:13 UTC (Thu) by paulj (subscriber, #341) [Link] (9 responses)

Well, Danese left Sun quite a few years ago. Also, be sure to read Simon Phipps response
(linked from the Wiki article you linked to).

I accept there are differences and difficulties. However, it is Suns' prerogative to define
how the software it created is to be derived from. Again though, Suns' licence does *not*
(AIUI+IANAL) prevent other OSes from re-using that code - not even Linux (even if it does
require collective action from Linux copyright holders). Reading the tea-leaves to find
evidence of Suns' "evil" intentions is however not at all productive, no matter whose side
you're on. Then projecting a moral duty of having to respect these *divined intentions* is,
again with all due respect, not very sensible.

If there are problems on some side, then the only way understanding can increase and so
solutions (if any) are ever be found is through dialogue.

More DTrace envy

Posted Jul 3, 2008 14:29 UTC (Thu) by drag (guest, #31333) [Link] (8 responses)

You have it backwards.

It's not that the GPL is incompatible with the CDDL... The CDDL was designed, specifically, to
be incompatible with the GPL. Even if all the Linux kernel developers decided that CDDL was
acceptable, then it still wouldn't matter. Sun _doesn't_want_it's_code_in_the_linux_kernel_.

That's it. They don't want Dtrace to be in Linux. They don't want ZFS in Linux. Get it? They
did it on purpose. So all the philosophical or political are the arguments that are MOOT. Sun
made sure of that. Sun says their code isn't going into Linux, then their code isn't going in.
There is absolutely no question about this.

Your the only one mentioning 'evil' here or anything like that. You can see their intentions
very clearly written in between the lines in the CDDL license even if you don't believe
Danese. All the legal ramifications have already been worked out years in advanced for
Mozilla-like licenses and Sun could of easily made it compatible with Linux, but they chose
not to do that. EASILY. No question about that at all.

Most everybody, unless they are loonies, is happy that Sun has their code under a open
license, even if it's intentionally incompatible with the (pre-existing and very well
established) GPL license.

They may change their mind in the future and make the license compatible, but until then it's
not going in.

You see, that's how you know Sun wouldn't mind having it's code in Linux. If they made the
license compatible then you'd know it was ok. Everything else is handwaving.

More DTrace envy

Posted Jul 3, 2008 14:55 UTC (Thu) by paulj (subscriber, #341) [Link] (6 responses)

Even if all the Linux kernel developers decided that CDDL was acceptable, then it still wouldn't matter. Sun _doesn't_want_it's_code_in_the_linux_kernel_.

Sun has published its code under the CDDL. It's a free software licence that's quite permissive. At least one other OS (if not two) has incorporated code (the crown jewels no less) from Solaris, by way of the CDDL licence. Take that + whatever statements you want from its officers that seem interpretive or estopping and ask your lawyer for an opinion.

What you feel Sun wants, or what you think the CDDL was designed specifically for, is amazingly speculative at best and largely irrelevant to anyone considering porting CDDL code.

More DTrace envy

Posted Jul 3, 2008 19:21 UTC (Thu) by bronson (subscriber, #4806) [Link]

> what you think the CDDL was designed specifically for, is ... largely irrelevant to anyone
considering porting CDDL code.

Do you seriously believe this?

Do you agree that the CDDL is incompatible with the GPLv2?  If so, then don't you think that
someone considering porting CDDL code to a GPL project had better consider whether his actions
are even legal?  That hardly sounds irrelevant!

If there's estoppel that would allow the CDDL to be used with the GPL, do you suppose you
share a link?  Every communication from Sun that I've seen has very specifically avoided this.

If Sun actually does want its CDDL code to be incorporated into GPLv2 projects, it would take
only tiny changes.  Since the GPL is older and more popular (http://freshmeat.net/stats/), one
would expect that Sun carefully considered researched GPL compatibility.  Even if the
incompatibility is an honest mistake, then why doesn't Sun make the tiny changes required now
to rectify the situation?

More DTrace envy

Posted Jul 5, 2008 19:13 UTC (Sat) by drag (guest, #31333) [Link] (4 responses)

> Sun has published its code under the CDDL. It's a free software licence that's quite
permissive. At least one other OS (if not two) has incorporated code (the crown jewels no
less) from Solaris, by way of the CDDL licence. Take that + whatever statements you want from
its officers that seem interpretive or estopping and ask your lawyer for an opinion.

They don't care if FreeBSD or OS X adopts ZFS or Dtrace because those operating systems are
irrelevant and are not competitive. Sun doesn't care if OS X adopts ZFS because they won't do
anything interesting with it. At most it will make OS X users feel better because they can
finally have a file system that doesn't suck worse then Vfat.

If Sun has it's software adopted by the Linux folks then they lose control over it. They will
improve it and incorporate it into Linux and it will be yet another reason why nobody has a
reason to choose Solaris over Linux.

Linux is now the dominate Unix system out there. Sun wants to maintain control over their
'ip'. They've done that with most everything they've released. They are learning to let go,
but it's slow coming.

Then explain to me why the hell Sun has not extended it's patent protections (use our IP and
we won't sue you) only to the users of CDDL-licensed code and not open source programmers and
users in general? Other people have done this (Redhat, Novell (not talking about the MS-Novell
agreement, but previous things they've done), it's certainly possible.

> What you feel Sun wants, or what you think the CDDL was designed specifically for, is
amazingly speculative at best and largely irrelevant to anyone considering porting CDDL code.

_read_the_license_. The license expresses intent. That's the point of it.

70%-90% of open source software used in a commercial environment is going to be licensed GPL.
Your telling me that Sun made CDDL problematic to be used in the majority of popular open
source software by ACCIDENT?

All they had to do was make a exception. They can still do it now. Mozilla did it.

They took and copied a license that everybody, including the original authors (Mozilla),
realizes is problematic when combined with other open source software and Sun didn't realize
it?

More DTrace envy

Posted Jul 6, 2008 11:10 UTC (Sun) by paulj (subscriber, #341) [Link] (3 responses)

You're the second person to have misread my (I thought fairly clear) comment, so I guess I
need to reply and clarift: I specifically said that *your* opinion of Suns' motivations in
choosing the CDDL was largely irrelevant (not least because motivations, even when generally
acknowledged, aren't that relevant).

Next (sorry to restate, but its important to the coherence of this post) you have been given
several reasonable, practical and good reasons why the GPLv2 would not have been acceptable to
Sun, regardless of Suns' motivations towards Linux, namely:

- Sun did not want to dictate to ISVs that they must GPL their code. (This one you have heard
directly from Bryan)

- Sun does not want licence-forking (to cover any rebuttal to the previous point of "so use
LGPL", as the LGPL can be converted to GPL, and ignoring the fact that the LGPL is far from
pretty)

- The GPLv2 is out of date with regard to patents. That Sun added patent cross-licensing+MAD
terms to CDDL suggests this may have been a factor. (Why it applies only to CDDL? I've no
idea.. I suspect there may be legal, technical difficulties in drafting the language to have
many other licences - particularly with regard to the 'MAD' aspect of the CDDL patent
language. Can you provide a pointer to the grants you refer to? Be interesting to read).

Next, ignoring the above and if we accept your argument: Exactly how did you develop this
massive sense of entitlement that you think it is your automatic right to Suns' code on
licensing terms favourable to your chosen OS? I'm a Free Software Foundation supporter and I
always understood that the ethical reasoning for companies to choose the free software was out
of respect for their *users*...

Finally, can you tell me with a straight face that had Sun chosen the GPL but it had chosen
the GPLv3 (imagining the GPLv3 had existed), that you'd then not be complaining here today
about Suns' choice of licence? Even though it too is incompatible with Linux to the *same
extent* as the CDDL is (namely: it'd require linux copyright holders to agree to update the
Linux not-quite-GPLv2 licence)?

More DTrace envy

Posted Jul 7, 2008 2:39 UTC (Mon) by clump (subscriber, #27801) [Link] (2 responses)

Forgive me, but the argument appears to be about whether CDDL-licensed can be used in Linux, or specifically GPL-licensed works. You started by saying:

Licences being incompatible is a moot, philosophical matter...

and:

Look, the CDDL appears to be absolutely fine with copyright holders of GPL works incorporating CDDL software and distributing it.

However this next quote is curious given your views:

Exactly how did you develop this massive sense of entitlement that you think it is your automatic right to Suns' code on licensing terms favourable to your chosen OS?

With the last quote, it looks like you agree that the CDDL and GPL aren't compatible. You object to people arguing *why* Sun chose the license. Fine. But you very much appear to give legitimacy to those not wishing to mix the licenses together.

More DTrace envy

Posted Jul 7, 2008 9:48 UTC (Mon) by paulj (subscriber, #341) [Link] (1 responses)

You have deliberately omitted the statements immediately following the ones you've quoted
which qualify those quotes. The first quote is particularly out of context, as the qualifying
statement is in the same sentence: "... if no one thinks the infringment matters.".

That's quite trollsome behaviour, something I would not have expected from an LWN subscriber.

More DTrace envy

Posted Jul 7, 2008 17:22 UTC (Mon) by clump (subscriber, #27801) [Link]

Ignoring your attacks, myself and some others here obviously think infringement matters.
That's kind of the point... It's also ironic that you've gone out of your way to condemn others
for thinking they know why Sun chooses the licenses it does, yet you consider it a deliberate
attempt to troll when someone points out what appears to be inconsistency in your logic.

By all means, disagree with my point if I am wrong but don't pretend you're taking the high
road.

More DTrace envy

Posted Jul 3, 2008 15:41 UTC (Thu) by zooko (guest, #2589) [Link]

Be careful using the notion of "Sun" as a person which can have intentions and plans and so
forth.  Even though the people who chose CDDL did so deliberately in order to avoid their
technologies being added into Linux (according to Danese Cooper's public comments and other
private communications that I've had with other Sun employees), that doesn't mean that Bryan
Cantrill so chose, or even that he is aware of or believes that it was so chosen.

Anyway, Bryan Cantrill's knowledge, opinions, and intentions are necessarily different than
those of other Sun employees, and neither is he wholly responsible for what the company does
nor is the company wholly responsible for what he does.

There is a sense in which companies cannot actually have intentions.  Fortunately, in our
society we allow them to enter into binding agreements, such as by publishing their software
under an open source licence, so that we no longer have to form a mental model of the
company's intention in order to know what we can do with their source code.

P.S.  I'm glad that free and open Solaris exists, as well as other free and open operating
systems such as the BSD's and apparently eventually Symbian.  If every computer in the world
ran Linux, we would all be poorer for it -- monoculture leads to stagnation and fragility.
Diversity and competition is the fount of creativity and excellence.

More DTrace envy

Posted Jul 3, 2008 14:33 UTC (Thu) by bcantrill (guest, #31087) [Link] (12 responses)

However pretending that legal uncertainty and explicitly distributing source code under GPL-incompatible terms aren't a (the) major issue, while claiming to want wider adoption of that code base under GNU/Linux and suggesting it isn't adopted because of NIH is just silly.

And now we have arrived at the central disconnect between us and the Linux community: we did not open source Solaris to get "wider adoption of that code base under GNU/Linux"; we open sourced Solaris because of our own business objectives, some of which I have previously described. Contrary to the beliefs of some in the GNU/Linux community, GNU/Linux and GPL are not the beginning and end of open source, and as we have explained, GPLv2 was not acceptable to us because we could not dictate licensing terms to in-kernel software writers, many of whom are 3rd parties who either will not or cannot relicense. Having an open source license that allowed for different license terms (including proprietary ones) was and is a constraint; allowing our technology to be ported to other operating systems was of secondary concern.

So there you have it: while we would welcome DTrace in Linux (and we will help and are helping those that would port it), it's not something we covet. If you want it, take it. If you don't, fine -- but know that many of your users would like to see you embrace the technology, and happen to care much more about solving their business problems than about legal arguments about why it's "impossible"...

More DTrace envy

Posted Jul 3, 2008 16:32 UTC (Thu) by willy (subscriber, #9762) [Link] (8 responses)

Brian, if you want DTrace to be part of Linux, just dual-license it.  You can release your
code under "CDDL or GPL" and then it can happily become part of Linux.  I, for one, would
welcome that.

More DTrace envy

Posted Jul 3, 2008 17:30 UTC (Thu) by bcantrill (guest, #31087) [Link] (7 responses)

Brian, if you want DTrace to be part of Linux, just dual-license it. You can release your code under "CDDL or GPL" and then it can happily become part of Linux. I, for one, would welcome that.

Dual licensing is something that the OpenSolaris community is very strongly against -- in part because dual licensing creates the possibility of a license-based fork. (Which given the enmity towards both Sun and the CDDL among many in the Linux camp, seems to be a very real possibility.) And again: we don't "want" DTrace to be a part of Linux -- it's up to the Linux community to want that, just as it was up to the FreeBSD, MacOS X and QNX developer communities to want it...

More DTrace envy

Posted Jul 3, 2008 19:33 UTC (Thu) by bronson (subscriber, #4806) [Link] (2 responses)

FreeBSD, MacOS X, QNX...  So all we have to do is relicense the Linux kernel under BSD?  Well,
why didn't you say so!  That sounds so easy!

Perhaps you're interpreting a specific licensing incompatibility as a lack of desire from the
Linux community?  I can assure you, the community as a whole really does want to integrate
DTrace.  A lot!  TONS.  It would happen in a matter of weeks if only the licenses allowed it
to be possible.

More DTrace envy

Posted Jul 3, 2008 20:00 UTC (Thu) by bcantrill (guest, #31087) [Link] (1 responses)

Now there's some big talk!  Do you have any idea of the technical details involved in this, or
are you one of the ESR groupies who believes that given "enough eyeballs" pixies and fairies
magically solve all problems?  I can assure you from working with Paul that the Linux
idiosyncrasies are making the DTrace port rougher going than most -- and porting DTrace is a
deeply technical endeavor on the best of days.  So it would not show up in a "matter of
weeks", even if it were GPLv2 and Torvalds himself were doing the port.  (Sacrilege, I know.)

More DTrace envy

Posted Jul 3, 2008 21:16 UTC (Thu) by bronson (subscriber, #4806) [Link]

I was careless and I'm sure you're right.  What I *should* have said is, "lots of Linux devs
would spend a lot of their time incorporating DTrace, if only the licenses allowed it."

But my point remains: you seem to be interpreting license problems as a lack of desire.  The
desire is there, no question!  If the licensing problems could just be fixed somehow, I'm
confident the Linux camp would devote amazing hours to DTrace.

As it is, they have to devote amazing hours to replicating DTrace.  :(

More DTrace envy

Posted Jul 3, 2008 19:42 UTC (Thu) by k8to (guest, #15413) [Link]

Wow, more disingenouousness.  I'm impressed.

More DTrace envy

Posted Jul 4, 2008 9:33 UTC (Fri) by dark (guest, #8483) [Link]

Dual licensing is something that the OpenSolaris community is very strongly against -- in part because dual licensing creates the possibility of a license-based fork.

No, it doesn't. Even if there were a GPL-only fork, SUN could simply use the GPL code in its CDDL products, under the "legal arguments don't matter" approach that you advocate. After all, they are both free software licenses.

Or does the shoe pinch on the other foot?

More DTrace envy

Posted Jul 6, 2008 2:13 UTC (Sun) by dirtyepic (guest, #30178) [Link]

Dual licensing is something that the OpenSolaris community is very strongly against -- in part because dual licensing creates the possibility of a license-based fork.

How can you fear a licensed-based fork when incompatible licenses are a "moot, philosophical matter"?

fork fears could be worked out

Posted Jul 7, 2008 18:09 UTC (Mon) by JoeBuck (subscriber, #2330) [Link]

The issue of a fork could be worked out. Sun count agree to dual-license DTrace, and Linus and the other kernel developers could agree to dual-license all improvements to that code that are accepted into the internal tree. This would neutralize any legitimate fears on the part of OpenSolaris developers that the Linux side would take and not give. It might require some re-architecting to separate out common code, from code that is Solaris-specific or Linux-specific. But Sun would gain a larger developer community to help improve the code.

More DTrace envy

Posted Jul 3, 2008 16:43 UTC (Thu) by nhippi (subscriber, #34640) [Link]

> know that many of your users would like to see you embrace the technology, and happen to
care much more about solving their business problems than about legal arguments about why it's
"impossible"

It works the other way around too. Many people would like to use solaris but can't since the
drivers are missing and care more about solving their business problems than legal arguments
why it's "impossible" to solaris to copy those drivers from Linux to solaris.

And to remind you, this problem was not created by Linux community or GPLv2, but by SUN. The
more paranoid side of community believes the problem was created on purpose.

In a hindsight it might seem it's not a problem to sun's customers, since Sun is surely
capable of rewriting (who was it again calling NiH?) all drivers needed to run the Sun servers
being sold, even if there already is a working GPLv2 driver. However, even Sun systems have
these USB/PCI-express expansion slots, where many people would like to attach interesting
hardware...

More DTrace envy

Posted Jul 7, 2008 10:26 UTC (Mon) by arafel (subscriber, #18557) [Link]

>but know that many of your users would like to see you embrace the 
>technology, and happen to care much more about solving their business 
>problems than about legal arguments about why it's "impossible"...

I'm sure it wasn't what you intended, but the tone of that comment makes it appear (at least
to me) like you're suggesting legal restrictions don't matter. Could you clarify that
slightly...?

To be honest, I'm having some difficulty with your post altogether. The suggestion that the
Linux developers are being deliberately obtuse in not integrating software which legally they
cannot integrate is, um, curious. Or do Sun not bother with such restrictions? ;-)

(Joking, I'm joking...)

choosing whether to allow dtrace integration with gnu/linux

Posted Jul 9, 2008 20:09 UTC (Wed) by mjw (subscriber, #16740) [Link]

we would welcome DTrace in Linux

You seem to flipflop a bit on the that point :) Certainly you don't have any obligation to make it possible by removing the legal uncertainty around the current dtrace CDDL license and how it interacts with the GPL. But as you can see from the discussions whenever you claim that dtrace would be better than sliced bread for integration into GNU/Linux systems (or at least so much better than what is currently only half-integrated, like Systemtap and friends), this legal uncertainty is the only real reason dtrace isn't even a choice in providing something better.

You keep claiming that there is no way to resolve the legal ambiguity without harming the OpenSolaris community. If true, then indeed dtrace will never be a choice for GNU/Linux as a whole. I am not convinced that is really impossible though. Pure GPL or LGPL is too copyleft for your taste. That can be rectified by adding an explicit exception for your use cases. This is what Sun did for OpenJDK which had the same constraints, there still was proprietary code that needed to be linked to. The other way is of course dual-licensing. Which you say you don't want because of the fear of forks. Which of course is true and could happen in theory. But Sun also did this for projects like Glassfish and NetBeans which were originally CDDL only, but are now dual licensed CDDL/GPL. So it seems at least Sun legal thinks this is an appropriate way to both protect a code base and make it more compatible with other communities. The suggestion from others to only do this if you can get some prominent figures in the community to say that they support the dual licensing and condemn single-license forks is a good suggestion. Richard Stallman did that explicitly when Mozilla dual licensed their code (see the legal FAQ Q/A 11 till 13).

Now I am not claiming that systemtap, lttng, tracepoints, markers, kprobes, utrace, uprobes, ftrace, etc. did everything so much better than dtrace. In fact you could see all the trouble they needed to go through to make their implementations as generic as possible before being (partially) accepted and integrated into mainline as an indication of the hard work that still is still ahead for dtrace to get integrated and accepted even if the legalities were cleared up. But they did make it so that eventually their code could be integrated legally into the mainline kernel and intermingled with each other to ultimately provide better, safe and powerful frameworks for observability under GNU/Linux.

It will be interesting to see how these projects morph GNU/Linux into a fully observable system such as solaris has through dtrace. It would be even more interesting if you could lift the legal uncertainties around dtrace and make it a true contender in this coopetive race towards full observability. It is your choice to make though.