Oh no I hoped it was about speeding up perf record that is actually a big thorn on my side, one I wrote a specific tool for... Depending on the number of probes you use, perf record can induce large latency hits or reduced throughput. Batching/buffer disk writes solves the problem for me. But I had to redevelop a perf parser to record/compress smarter. And for network streaming (no touching the disk is even better...).
60x speed-up of Linux “perf”
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Re: 60x speed-up of Linux “perf”
#82It is a tough feeling to see someone else's design for a library that would be literally perfect for my needs, but I'm unable to use it because of the license, so I have to spend weeks implementing my own inferior version while carefully avoiding making the code too similar to what I happen to remember. I'm past believing that I'm smart enough to always be able to come up with/reimplement a competent enough solution…
> carefully avoiding making the code too similar to what I happen to remember Is this really necessary? The GPL allows you to read and study the software. Is it really copyright infringement if you take your understanding and make your own program? Are people really forced to come up with convoluted new ways to solve the same problem just to avoid any similarity to existing work?
The issue is that the only way to guarantee no liability is a clean room implementation. It's why most open source reimplementations require no mention or examination of the source/machine code. Google got dinged over a trivial method they copied in their java implementation, even though it was extremely trivial. You can't risk any chance of copying, regardless of how trivial the code.
Re: 60x speed-up of Linux “perf”
#83It is a tough feeling to see someone else's design for a library that would be literally perfect for my needs, but I'm unable to use it because of the license, so I have to spend weeks implementing my own inferior version while carefully avoiding making the code too similar to what I happen to remember. I'm past believing that I'm smart enough to always be able to come up with/reimplement a competent enough solution…
> carefully avoiding making the code too similar to what I happen to remember Is this really necessary? The GPL allows you to read and study the software. Is it really copyright infringement if you take your understanding and make your own program? Are people really forced to come up with convoluted new ways to solve the same problem just to avoid any similarity to existing work?
Think about it this way. If a panel of jurists who only half understood the expert testimony saw your code side by side with other code would it look like blatant copying or not?
Re: 60x speed-up of Linux “perf”
#84Earlier quoted context omitted.
Not sure if this is a pisstake on my argument, but a world without copyright (or something similar) would be a world of endless exploitation and stifled innovation.
Copyright as it exists today does an awful lot of exploitation-enabling and innovation-stifling in itself. (And that's ignoring the rest of the IP suite.)
This is like saying "cops today do a lot of nasty stuff, let's get rid of all cops". The result is pure, unmitigated anarchy, looting, murder, and lawlessness.
I don't find either to be useful lines of thinking.
Re: 60x speed-up of Linux “perf”
#85It is a tough feeling to see someone else's design for a library that would be literally perfect for my needs, but I'm unable to use it because of the license, so I have to spend weeks implementing my own inferior version while carefully avoiding making the code too similar to what I happen to remember. I'm past believing that I'm smart enough to always be able to come up with/reimplement a competent enough solution…
> carefully avoiding making the code too similar to what I happen to remember Is this really necessary? The GPL allows you to read and study the software. Is it really copyright infringement if you take your understanding and make your own program? Are people really forced to come up with convoluted new ways to solve the same problem just to avoid any similarity to existing work?
It depends on what derivative work means, and finding out the specifics may mean spending time in court.
GPLv3 says 'To “modify” a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a “modified version” of the earlier work or a work “based on” the earlier work.'
If you read and study a work, and then write something new that does the same thing, that may be considered adapting or copying from (parts of) the original work.
Re: 60x speed-up of Linux “perf”
#86Oh no I hoped it was about speeding up perf record that is actually a big thorn on my side, one I wrote a specific tool for... Depending on the number of probes you use, perf record can induce large latency hits or reduced throughput. Batching/buffer disk writes solves the problem for me. But I had to redevelop a perf parser to record/compress smarter. And for network streaming (no touching the disk is even better...…
Sorry! :-) It was very much just scratching a particular itch I had related to cargo-flamegraph...
Re: 60x speed-up of Linux “perf”
#87Earlier quoted context omitted.
What is a good source to get an understanding of all the Licenses and their relation?
Here's a brief summary of major licenses: MIT, X11, BSD (2- or 3-clause), and more similar ones I can't name off the top of my head: these are the basic do-what-you-want license, the only requirements are things that every (good) license already has, such as standard limitation-of-warranty clauses and retention of copyright notice requirements. Apache (v2): This is the next stage up, which means that the text is leng…
Nice writeup, and for all intents and purposes seems accurate for anyone wondering.
Re: 60x speed-up of Linux “perf”
#88> Michał Sidor suggests building against libbfd, something that the Debian maintainers don’t want to do. "don't want to" isn't quite correct - they can't . Perf is licensed under the GPLv2, libbfd under the GPLv3. The licenses are incompatible, which makes the combination unredistributable - which is what Debian would be doing with it. Debian is legally not allowed to do this.
Kind of ironic that RMS campained against proprietary software to allow reuse of code. Now we have two islands of open source code ... .
Two? Are the AGPL licenses compatible? How about GPL licenses with exceptions for some APIs as used by OpenJDK?
Re: 60x speed-up of Linux “perf”
#89Earlier quoted context omitted.
IMO it's not "GPL virality" that is at the root of the issue here. The authors' decision to license theis works this way causes the problem. You can still ask both libraries' authors for relicensing their work in a less restricted / more compatible way. If they don't want to do that, then being authors and owning their copyrights, that's their right to do. That's nothing I would blame on the GPL. I mean we should be…
> The authors' decision to license theis works this way causes the problem. I'm not sure how you can rationally make an argument for a framework that literally limits the use of improved or more performant code/technology/understanding simply because it does not share a philosophical view of IP/ownership/sharing. This is the core of the problem with IP in the real world as well, and I find it mind-boggling that we do…
It doesn't limit it any more than if it were proprietary and you couldn't afford it.
Re: 60x speed-up of Linux “perf”
#90It is a tough feeling to see someone else's design for a library that would be literally perfect for my needs, but I'm unable to use it because of the license, so I have to spend weeks implementing my own inferior version while carefully avoiding making the code too similar to what I happen to remember. I'm past believing that I'm smart enough to always be able to come up with/reimplement a competent enough solution…
> carefully avoiding making the code too similar to what I happen to remember Is this really necessary? The GPL allows you to read and study the software. Is it really copyright infringement if you take your understanding and make your own program? Are people really forced to come up with convoluted new ways to solve the same problem just to avoid any similarity to existing work?
What I wasn't sure of is, as long as I never actually incorporate the original code, if basing your fundamental design on something counts as infringement. I find it hard to see the difference between taking some class definitions and changing the variable names and going off to use what you learned from other people only to realize you arrived at the same design as they did because doing anything else would mean the implementation would be worse than what you now know it could be.
I don't have much of an understanding of copyright when it comes to cases like those, but my worry is that declaring that your open-source codebase is merely inspired by codebase X with this specific code in the case of these specific data structures would still count as infringement in a court of law. However, I don't intend to infringe on the licenses of the original, and do not intend to directly copy any code.