On 3 June 2016 at 17:10, Rafael Espíndola rafael.espindola@gmail.com wrote:
Do keep in mind you are comparing a 11 year old project and a 11 month old one. There is a lot more churn on the 11 month old one.
LLD is at least 5 years old. Every time you re-write it doesn't reset history.
Again, I am truly sorry we were unable to come up with a perfect design the first time. For the record, I don't think it is perfect yet. There will likely be more big changes to lld. That is the cost of trying to build as good a linker as we can.
This is not about what you do. It's about *how* you do it.
We have developers trying to create a linker. They are working on LLD because Chris wanted a true LLVM linker. But it seems that you want a project that you can do whatever you want, whenever you want.
This is *NOT* open source. Right now, LLD is *nothing more* than Rui's and Rafael's pet project. I cannot recommend Linaro to collaborate on those terms, and I sincerely recommend anyone that is listening to this thread to not do so either.
Being open source doesn't mean I get to implement what someone else wants. You are more than welcome to send patches, but they have avoid harming the rest of the linker. In particular, at this early stage they cannot harm its development. Once we have a mature project we can actually evaluate tradeoff.
We're clearly not welcome to send patches. We did, and you re-wrote it and committed without asking the original author.
So, the plan is to wait for you to finish the initial implementation alone? Again? What do we do in the interim? How many times are we going to go through this?
I have waited 2 years before LLD was barely useful, then Adhemerval implemented the AArch64 back-end. Then you destroyed and now we have waited another year, but we're still unable to collaborate. If anything, now it's even harder than it was last year.
Why can't we help with the design, too? We know about ARM and AArch64, that's what we do, and we can provide you with the expertise without having to go on your own doing everything. That is the whole point of collaborative development, and it seems that you're missing this point.
And just like we did, you are more than welcome to try to write something better. Please let us know how it goes.
Is this the position of every LLD developer?
Rui, Nick, Chris?
I'm seriously looking for others to chime in and let me know if that is the final stance on LLD, so that I can finally write it off and go work on another linker.
If the official position is that LLD is a project that only Rui and Rafael can design and implement for another 2~3 years, I *cannot* recommend Linaro and its members to participate.
cheers, --renato
On Fri, Jun 3, 2016 at 9:29 AM, Renato Golin renato.golin@linaro.org wrote:
On 3 June 2016 at 17:10, Rafael Espíndola rafael.espindola@gmail.com wrote:
Do keep in mind you are comparing a 11 year old project and a 11 month old one. There is a lot more churn on the 11 month old one.
LLD is at least 5 years old. Every time you re-write it doesn't reset history.
Again, I am truly sorry we were unable to come up with a perfect design the first time. For the record, I don't think it is perfect yet. There will likely be more big changes to lld. That is the cost of trying to build as good a linker as we can.
This is not about what you do. It's about *how* you do it.
We have developers trying to create a linker. They are working on LLD because Chris wanted a true LLVM linker. But it seems that you want a project that you can do whatever you want, whenever you want.
This is *NOT* open source. Right now, LLD is *nothing more* than Rui's and Rafael's pet project. I cannot recommend Linaro to collaborate on those terms, and I sincerely recommend anyone that is listening to this thread to not do so either.
Renato, it is not appropriate to call it my and Rafael's pet project. First of all, Rafael and me are working on it for different purposes and probably have different visions (although our taste on good code and good design seems similar.) I'm interested in using it in my company and on FreeBSD, for example. Rafael and I have no side channel to communicate, and we are just collaborating openly on this mailing list.
You overlooked a lot of contributions that has been made to LLD. George designed and wrote a great deal of relocation handling code and TLS optimizations besides other contributions. Peter came up with a different symbol table design, sent a proposal to the mailing list for discussion, and implemented it (even though Peter and I are working for the same company, that was not a coordinated effort, and the design change proposal was out of the blue to me. I was surprised by his improvement.) Simon implemented all of MIPS code that's pretty tricky. Davide is contributing to AArch64 and LTO. There are many more contributors. I'm truly respectful to all the contributors, and attributing these efforts to someone's pet project is honestly a bit insulting.
I have never declined contributions by saying that "I know better." I requested design documents (because I don't know better!) when contributors seem to be starting large design changes, but that was needed for discussion. If you want to do some large change, you want to convince other collaborators that your design will work. It is I think a usual process.
Needless to say, I don't think I (and Rafael) should get a special treatment. Both do not have right to submit without convincing other collaborators. For example, just last week, I sent a patch which I truly believed non-controversial and good one for review, and got rejected unexpectedly by Sean. I had to convince him. That's how it works.
I sincerely request you to retract your recommendation to not collaborate with us.
I'm not protecting what Rafael did. Rafael, even if you think your patch had less common with the patch that's under review, they overlapped each other with a great deal. Reviewing one patch and submitting a conflicting one at the same time is not an appropriate behavior, and I do understand why it disappointed Adhemerval and Renato. You needed to send it to review and explain yours if you believe yours is different and better.
Being open source doesn't mean I get to implement what someone else
wants. You are more than welcome to send patches, but they have avoid harming the rest of the linker. In particular, at this early stage they cannot harm its development. Once we have a mature project we can actually evaluate tradeoff.
We're clearly not welcome to send patches. We did, and you re-wrote it and committed without asking the original author.
So, the plan is to wait for you to finish the initial implementation alone? Again? What do we do in the interim? How many times are we going to go through this?
I have waited 2 years before LLD was barely useful, then Adhemerval implemented the AArch64 back-end. Then you destroyed and now we have waited another year, but we're still unable to collaborate. If anything, now it's even harder than it was last year.
Why can't we help with the design, too? We know about ARM and AArch64, that's what we do, and we can provide you with the expertise without having to go on your own doing everything. That is the whole point of collaborative development, and it seems that you're missing this point.
And just like we did, you are more than welcome to try to write something better. Please let us know how it goes.
Is this the position of every LLD developer?
I cannot say about every developer, but at least to me, my answer is yes, of course.
Rui, Nick, Chris?
I'm seriously looking for others to chime in and let me know if that is the final stance on LLD, so that I can finally write it off and go work on another linker.
If the official position is that LLD is a project that only Rui and Rafael can design and implement for another 2~3 years, I *cannot* recommend Linaro and its members to participate.
On Fri, Jun 3, 2016 at 10:47 AM, Rui Ueyama ruiu@google.com wrote:
On Fri, Jun 3, 2016 at 9:29 AM, Renato Golin renato.golin@linaro.org wrote:
On 3 June 2016 at 17:10, Rafael Espíndola rafael.espindola@gmail.com wrote:
Do keep in mind you are comparing a 11 year old project and a 11 month old one. There is a lot more churn on the 11 month old one.
LLD is at least 5 years old. Every time you re-write it doesn't reset history.
Again, I am truly sorry we were unable to come up with a perfect design the first time. For the record, I don't think it is perfect yet. There will likely be more big changes to lld. That is the cost of trying to build as good a linker as we can.
This is not about what you do. It's about *how* you do it.
We have developers trying to create a linker. They are working on LLD because Chris wanted a true LLVM linker. But it seems that you want a project that you can do whatever you want, whenever you want.
This is *NOT* open source. Right now, LLD is *nothing more* than Rui's and Rafael's pet project. I cannot recommend Linaro to collaborate on those terms, and I sincerely recommend anyone that is listening to this thread to not do so either.
Renato, it is not appropriate to call it my and Rafael's pet project. First of all, Rafael and me are working on it for different purposes and probably have different visions (although our taste on good code and good design seems similar.) I'm interested in using it in my company and on FreeBSD, for example. Rafael and I have no side channel to communicate, and we are just collaborating openly on this mailing list.
You overlooked a lot of contributions that has been made to LLD. George designed and wrote a great deal of relocation handling code and TLS optimizations besides other contributions. Peter came up with a different symbol table design, sent a proposal to the mailing list for discussion, and implemented it (even though Peter and I are working for the same company, that was not a coordinated effort, and the design change proposal was out of the blue to me. I was surprised by his improvement.) Simon implemented all of MIPS code that's pretty tricky. Davide is contributing to AArch64 and LTO. There are many more contributors. I'm truly respectful to all the contributors, and attributing these efforts to someone's pet project is honestly a bit insulting.
I have never declined contributions by saying that "I know better." I requested design documents (because I don't know better!) when contributors seem to be starting large design changes, but that was needed for discussion. If you want to do some large change, you want to convince other collaborators that your design will work. It is I think a usual process.
Needless to say, I don't think I (and Rafael) should get a special treatment. Both do not have right to submit without convincing other collaborators. For example, just last week, I sent a patch which I truly believed non-controversial and good one for review, and got rejected unexpectedly by Sean. I had to convince him. That's how it works.
I sincerely request you to retract your recommendation to not collaborate with us.
I'm not protecting what Rafael did. Rafael, even if you think your patch had less common with the patch that's under review, they overlapped each other with a great deal. Reviewing one patch and submitting a conflicting one at the same time is not an appropriate behavior, and I do understand why it disappointed Adhemerval and Renato. You needed to send it to review and explain yours if you believe yours is different and better.
Being open source doesn't mean I get to implement what someone else
wants. You are more than welcome to send patches, but they have avoid harming the rest of the linker. In particular, at this early stage they cannot harm its development. Once we have a mature project we can actually evaluate tradeoff.
We're clearly not welcome to send patches. We did, and you re-wrote it and committed without asking the original author.
So, the plan is to wait for you to finish the initial implementation alone? Again? What do we do in the interim? How many times are we going to go through this?
I have waited 2 years before LLD was barely useful, then Adhemerval implemented the AArch64 back-end. Then you destroyed and now we have waited another year, but we're still unable to collaborate. If anything, now it's even harder than it was last year.
Why can't we help with the design, too? We know about ARM and AArch64, that's what we do, and we can provide you with the expertise without having to go on your own doing everything. That is the whole point of collaborative development, and it seems that you're missing this point.
And just like we did, you are more than welcome to try to write something better. Please let us know how it goes.
Is this the position of every LLD developer?
I cannot say about every developer, but at least to me, my answer is yes, of course.
Oh, wait! I may have been misread the sentence. I read "write better code in LLD to replace existing part of LLD". I had totally no intention to say that you should try something outside LLD. I'm sorry for the confusion.
Rui, Nick, Chris?
I'm seriously looking for others to chime in and let me know if that is the final stance on LLD, so that I can finally write it off and go work on another linker.
If the official position is that LLD is a project that only Rui and Rafael can design and implement for another 2~3 years, I *cannot* recommend Linaro and its members to participate.
On 3 June 2016 at 18:47, Rui Ueyama ruiu@google.com wrote:
Renato, it is not appropriate to call it my and Rafael's pet project.
Hi Rui,
I apologise, that was wrong in all levels.
I know how much other people have contributed, but these people are on the inside already, so their contributions are more easily accepted.
We have been trying to contribute for more than a year and have yet failed to get in the loop. We were asked to wait for 2 years until the core linker was ready, we did. Last year we wasted 3 months on the old back end, and were told to wait again. Now we wasted another 4 months this year, and all we did was re-written without warning. I cannot recommend Linaro to continue wasting any more time.
I have never declined contributions by saying that "I know better." I requested design documents (because I don't know better!) when contributors seem to be starting large design changes, but that was needed for discussion. If you want to do some large change, you want to convince other collaborators that your design will work. It is I think a usual process.
Again, I apologise. Your behaviour is by no means comparable to Rafael's.
But he's taking the stance and speaking for the LLD community, at least that's what it looks like to me.
Linaro is not a drive-by contributor to LLVM, or even to LLD. And if even long time contributors to LLVM, and professional developers with decades of experience in linker technology, are getting this treatment, what does that say about others?
I sincerely request you to retract your recommendation to not collaborate with us.
Those are based on facts. Not about you, but about interacting the the LLD community, which unfortunately, you're part of.
I don't want to blame people, I want to produce software, and the LLD community is blocking our progress for 3 years already.
I had totally no intention to say that you should try something outside LLD. I'm sorry for the confusion.
That's what I meant, yes. :)
Let me re-write my question to make sure we get over the language barrier:
Is the LLD community in agreement that a few core developers can and will continue to block contributions, while doing all the work themselves until such a day that it's deemed ready by the same developers, in which time that everyone else will then, be allowed to collaborate?
Or is the community in disagreement with Rafael's behaviour and will try to not only curb it, but openly and actively promote more collaboration by allowing other people to participate in the design and implementation of their own targets?
If the former, than I'll respectfully move to MCLinker. If the latter, than I expect due process and future collaborations, including letting Adhemerval complete the AArch64 TLS implementation with proper code review, not bypass re-writes.
As I said earlier, we'll continue to collaborate on LLD for the time being on both ARM and AArch64 targets, and the next months will be a test of how the LLD community will respond to this incident.
Peter Smith has just sent an initial implementation for the ARM target (D20951), and he's working on improving it to be able to self-host Clang on ARM in the next few months. I seriously hope that this doesn't end up as another bad decision.
cheers, --renato
On Fri, Jun 3, 2016 at 12:23 PM, Renato Golin renato.golin@linaro.org wrote:
On 3 June 2016 at 18:47, Rui Ueyama ruiu@google.com wrote:
Renato, it is not appropriate to call it my and Rafael's pet project.
Hi Rui,
I apologise, that was wrong in all levels.
I know how much other people have contributed, but these people are on the inside already, so their contributions are more easily accepted.
We have been trying to contribute for more than a year and have yet failed to get in the loop. We were asked to wait for 2 years until the core linker was ready, we did. Last year we wasted 3 months on the old back end, and were told to wait again. Now we wasted another 4 months this year, and all we did was re-written without warning. I cannot recommend Linaro to continue wasting any more time.
I have never declined contributions by saying that "I know better." I requested design documents (because I don't know better!) when
contributors
seem to be starting large design changes, but that was needed for discussion. If you want to do some large change, you want to convince
other
collaborators that your design will work. It is I think a usual process.
Again, I apologise. Your behaviour is by no means comparable to Rafael's.
But he's taking the stance and speaking for the LLD community, at least that's what it looks like to me.
Linaro is not a drive-by contributor to LLVM, or even to LLD. And if even long time contributors to LLVM, and professional developers with decades of experience in linker technology, are getting this treatment, what does that say about others?
I sincerely request you to retract your recommendation to not collaborate with us.
Those are based on facts. Not about you, but about interacting the the LLD community, which unfortunately, you're part of.
I don't want to blame people, I want to produce software, and the LLD community is blocking our progress for 3 years already.
I had totally no intention to say that you should try something outside
LLD. I'm sorry for the confusion.
That's what I meant, yes. :)
Let me re-write my question to make sure we get over the language barrier:
Is the LLD community in agreement that a few core developers can and will continue to block contributions, while doing all the work themselves until such a day that it's deemed ready by the same developers, in which time that everyone else will then, be allowed to collaborate?
No, and I think I've never blocked any contributions for such reason. I apologize I didn't review Adhemerval patch. My knowledge of AArch64 and TLS optimizations is limited, and since Rafael (who knows most about relocation handling in LLD) was reviewing it, I deferred it to him. I'll try to review it next time.
Or is the community in disagreement with Rafael's behaviour and will try to not only curb it, but openly and actively promote more collaboration by allowing other people to participate in the design and implementation of their own targets?
Yes, including the part that Rafael should have done this differently.
Rafael, I think you want to slow down a little bit and take more time on getting consensus on commits, even for things that you think "too obvious". Code review for LLD is usually fast, and overall it would make the development even faster because of smooth communication between collaborators.
If the former, than I'll respectfully move to MCLinker. If the latter, than I expect due process and future collaborations, including letting Adhemerval complete the AArch64 TLS implementation with proper code review, not bypass re-writes.
As I said earlier, we'll continue to collaborate on LLD for the time being on both ARM and AArch64 targets, and the next months will be a test of how the LLD community will respond to this incident.
Peter Smith has just sent an initial implementation for the ARM target (D20951), and he's working on improving it to be able to self-host Clang on ARM in the next few months. I seriously hope that this doesn't end up as another bad decision.
cheers, --renato
On 3 June 2016 at 21:02, Rui Ueyama ruiu@google.com wrote:
Is the LLD community in agreement that a few core developers can and will continue to block contributions, while doing all the work themselves until such a day that it's deemed ready by the same developers, in which time that everyone else will then, be allowed to collaborate?
No, and I think I've never blocked any contributions for such reason. I apologize I didn't review Adhemerval patch. My knowledge of AArch64 and TLS optimizations is limited, and since Rafael (who knows most about relocation handling in LLD) was reviewing it, I deferred it to him. I'll try to review it next time.
Or is the community in disagreement with Rafael's behaviour and will try to not only curb it, but openly and actively promote more collaboration by allowing other people to participate in the design and implementation of their own targets?
Yes, including the part that Rafael should have done this differently.
Rafael, I think you want to slow down a little bit and take more time on getting consensus on commits, even for things that you think "too obvious". Code review for LLD is usually fast, and overall it would make the development even faster because of smooth communication between collaborators.
Rui,
Thank you very much for your response.
I'm relieved that I had not made the wrong decision about LLD some years back, and I really appreciate the work you have being putting on it.
Looking forward to more collaborations in the present and future!
cheers, --renato
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