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Dtrace for Linux

gnu.wildebeest.org

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Re: Dtrace for Linux

#11

Post by simcop2387 »

4ad wrote: post #8
rhinoceraptor wrote: post #5

Earlier quoted context omitted.

If ZFS were also relicensed, would Illumos be able to relicense OpenZFS as well, even with the divergence?

OpenZFS can't be relicensed as GPL since FreeBSD won't be able to use it. Perhaps it could be dual-licensed, not sure, but that would be bad for FreeBSD as well. If it would be integrated into the mainline Linux kernel, I don't believe FreeBSD could merge back subsequent ZFS changes done on the Linux side. If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able…

Instead of relicensing to gpl it could be relicensed to bsd or MIT both of which can be included in mainline Linux kernel and in bsd land too, without compromising future development

edit: stupid phone autocorrect on the train this morning. s/not/MIT/

Re: Dtrace for Linux

#12

Post by benmmurphy »

it looks like the dtrace port can be used by non-privileged users (i'm just guessing because there is some uid checks in there). just be aware there has been a bunch of fixes applied to the illumos version of dtrace and i'm pretty sure at least 1 (maybe more) have not been applied to this version.

Re: Dtrace for Linux

#13

Post by boomboomsubban »

insertnickname wrote: post #10
4ad wrote: post #8

Earlier quoted context omitted.

OpenZFS can't be relicensed as GPL since FreeBSD won't be able to use it. Perhaps it could be dual-licensed, not sure, but that would be bad for FreeBSD as well. If it would be integrated into the mainline Linux kernel, I don't believe FreeBSD could merge back subsequent ZFS changes done on the Linux side. If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able…

FreeBSD is OK with CDDL but not GPL?

Yeah, the CDDL is weak copyleft, meaning derived works don't need to be licensed CDDL. The GPL is strong copyleft, and could force all of FreeBSD to adopt the GPL.

Re: Dtrace for Linux

#14

Post by [deleted] »

insertnickname wrote: post #10
4ad wrote: post #8

Earlier quoted context omitted.

OpenZFS can't be relicensed as GPL since FreeBSD won't be able to use it. Perhaps it could be dual-licensed, not sure, but that would be bad for FreeBSD as well. If it would be integrated into the mainline Linux kernel, I don't believe FreeBSD could merge back subsequent ZFS changes done on the Linux side. If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able…

FreeBSD is OK with CDDL but not GPL?

[deleted]

Re: Dtrace for Linux

#15

Post by boomboomsubban »

4ad wrote: post #8
rhinoceraptor wrote: post #5

Earlier quoted context omitted.

If ZFS were also relicensed, would Illumos be able to relicense OpenZFS as well, even with the divergence?

OpenZFS can't be relicensed as GPL since FreeBSD won't be able to use it. Perhaps it could be dual-licensed, not sure, but that would be bad for FreeBSD as well. If it would be integrated into the mainline Linux kernel, I don't believe FreeBSD could merge back subsequent ZFS changes done on the Linux side. If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able…

>If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able to get all changes, but it would still be annoying to actually use ZFS in Linux for the same reason it is annoying to use it now, even though the legal uncertainties would disappear

Couldn't it be developed outside the mainline Linux tree but still have improvements ported to the kernel? If I understand things correctly, thats basically how xorg handles drivers.

Re: Dtrace for Linux

#16

Post by takeda »

jsiepkes wrote: post #7
rhinoceraptor wrote: post #5

Earlier quoted context omitted.

If ZFS were also relicensed, would Illumos be able to relicense OpenZFS as well, even with the divergence?

If Oracle's sources would be GPL'ed all OpenZFS changes would also have to be put under the GPL (or dual licensed) if you want to use those. OpenZFS doesn't have a CLA I think so that might be somewhat of a problem. Then again most ZFS changes were made by people for their employers (Joyent, Delphix, etc.) so it might be that only a few companies (...and Allan Jude ;-) need to give their blessing.

I don't think the license can be done retroactively. I mean Oracle owns copyright to major part of ZFS and they can change license to that. But the contributions done to OpenZFS each developer owns copyright to their own work.

I believe the original code could be treated as either CDDL or GPL, but the code that was contributed before license change would still be under CDDL.

I think OpenZFS project owners would need to track down every contributor and get their permission to change the license. Perhaps it wouldn't be terribly hard with git/svn blame command. The only problem would be if the original authors were no longer available, but hopefully that code could be just rewritten by someone else.

Things would be much easier if every author would surrender their copyright to OpenZFS project, but some people might have problem with it since then you surrender all claims to the code.

Re: Dtrace for Linux

#17

Post by LukeShu »

boomboomsubban wrote: post #13
insertnickname wrote: post #10

Earlier quoted context omitted.

FreeBSD is OK with CDDL but not GPL?

Yeah, the CDDL is weak copyleft, meaning derived works don't need to be licensed CDDL. The GPL is strong copyleft, and could force all of FreeBSD to adopt the GPL.

To clarify that a bit: The CDDL is a per-file copyleft; you must provide the sources of the CDDL-licensed source files. The GPL is a per-program copyleft; you must provide the sources of the entire program if it contains GPL-licensed code; the source of the entire program effectively becomes GPL-licensed if you incorporate GPL-licensed code.

If I made a closed derivative of the FreeBSD kernel, I'd have to provide the (CDDL) ZFS sources, but nothing else. If ZFS were GPL, I'd have to provide the sources to the entire kernel.

Re: Dtrace for Linux

#18

Post by Conan_Kudo »

takeda wrote: post #16
jsiepkes wrote: post #7

Earlier quoted context omitted.

If Oracle's sources would be GPL'ed all OpenZFS changes would also have to be put under the GPL (or dual licensed) if you want to use those. OpenZFS doesn't have a CLA I think so that might be somewhat of a problem. Then again most ZFS changes were made by people for their employers (Joyent, Delphix, etc.) so it might be that only a few companies (...and Allan Jude ;-) need to give their blessing.

I don't think the license can be done retroactively. I mean Oracle owns copyright to major part of ZFS and they can change license to that. But the contributions done to OpenZFS each developer owns copyright to their own work. I believe the original code could be treated as either CDDL or GPL, but the code that was contributed before license change would still be under CDDL. I think OpenZFS project owners would need…

> Things would be much easier if every author would surrender their copyright to OpenZFS project, but some people might have problem with it since then you surrender all claims to the code.

This is super-dangerous. There's a reason that copyright assignment agreements are rare. In a lot of jurisdictions, it's not even possible.

Most copyright license agreements instead force unlimited sublicensing grants, which provides de facto ownership of the copyrighted code, rather than de jure ownership.

Re: Dtrace for Linux

#19

Post by burke »

brendangregg wrote: post #9

Unfortunately for DTrace, this is too late. Oracle should have done this years ago. Now Linux has a more powerful tracer builtin, eBPF, and it would be a backwards step to switch the kernel code to DTrace (assuming the DTrace port is completed, which it is not). I'm sure this will not be lost on the maintainers, who have the ultimate say as to what is included in Linux mainline. The only hope for DTrace is to have th…

As a non-expert, I still find this exciting. While eBPF may be more powerful, I find it far less approachable than DTrace. Perhaps this is just a failure to discover the right documentation. I use DTrace now and then on macOS and have resented that I can't really use it on Linux as well.

Re: Dtrace for Linux

#20

Post by HankB99 »

4ad wrote: post #8
rhinoceraptor wrote: post #5

Earlier quoted context omitted.

If ZFS were also relicensed, would Illumos be able to relicense OpenZFS as well, even with the divergence?

OpenZFS can't be relicensed as GPL since FreeBSD won't be able to use it. Perhaps it could be dual-licensed, not sure, but that would be bad for FreeBSD as well. If it would be integrated into the mainline Linux kernel, I don't believe FreeBSD could merge back subsequent ZFS changes done on the Linux side. If OpenZFS were relincensed and developed outside the mainline Linux tree (as it is now), FreeBSD would be able…

> ... but it would still be annoying to actually use ZFS in Linux for the same reason it is annoying to use it now.

For those of us who are ignorant of what is annoying to use now (I raise my hand) can you elaborate? I'm fooling around with it on Debian Stretch and Ubuntu 16.04 LTS and haven't yet found it annoying (except for the challenge of finding where the various command line switches are documented...)

I was particularly surprised to find it was an 'apt get' away on Debian, but I do have non-free repos enabled.

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