Renato Golin via llvm-dev
2016-Jun-03 00:21 UTC
[llvm-dev] [lld] r271569 - Start adding tlsdesc support for aarch64.
On 2 June 2016 at 23:22, Rafael Espíndola <rafael.espindola at gmail.com> wrote:> Because the patch includes way too much and doesn't explain what it is doing.So let me get this straight: someone publishes a patch, you don't like it, you do some private investigations and commit whatever you want without even notifying the original authors? I don't know how you work at your company, but this is not how open source development works. This is not the first time either that you step over people's toes with your "design decisions" that you don't share with anyone. Last year, Adhemerval has worked for three months to get the LLD AArch64 back-end working and out of the blue, no warning, the whole back-end was yanked. It doesn't matter if it was the right decision or not in the long term, we don't just yank things, especially not before some deliberation on the list. See how long is taking for the new pass manager to be enabled, or FastIsel or the new Selection, or the new register allocators, etc. That's not how open source works and I assumed you knew that.> That is a general problem with aarch64, the documentation is missing > and comments have to make due. I had a lot of work to rewrite the > original aarch64 patches to be in line with the rest of lld and I > didn't want to have to do the same for tls.You shouldn't be rewriting *any* patch, but asking the original authors to do that themselves. There is a pattern that I'm seeing and that's that *you* refuse or dismiss more patches than most other people. There are many of your comments on reviews that are just personal, and then you step over people's toes and commits yourself. This does not scale. But more importantly, it puts into doubt the validity of the tool you're so hardly defending. You see, 3 years ago, I was asked to choose between MCLinker and LLD. MCLinker was a linker for all purposes, but Chris Lattner convinced me that LLD is the LLVM linker, and we should be focusing all efforts there. It goes against the commercial interests of Linaro members to choose such a premature technology, and it did put them back years of development, because MCLinker was very close to ready, and MediaTek, despite what people said, was very willing to accept our help. But in the interest of the community, and the open source nature of my work, I have decided to pursue LLD and managed to convince Linaro to put two people working on it. But now, I'm re-evaluating all my strategy, and sincerely, I do not trust the LLD community anymore.> The delay was because of the above mentioned issues. I wanted to make > sure there was a solid foundation.Some patches are quick to review, others take 6 months. If you work in open source you have *got* to understand that. If you're not willing to take that cost, than please, refrain from working open source.> Sorry, no.I understand your position, but you have to understand mine. I therefore call into question your ability to care about such an important project of the LLVM community. I sincerely believe that your actions are harming the project, and the people trying to help. I appreciate the value of your contribution, I really do, but if you don't change your way to handle open source contributions, LLD will, whether you like it or not, become irrelevant and be replaced. Such is the nature of open source. cheers, --renato
Rafael Espíndola via llvm-dev
2016-Jun-03 00:35 UTC
[llvm-dev] [lld] r271569 - Start adding tlsdesc support for aarch64.
On 2 June 2016 at 17:21, Renato Golin <renato.golin at linaro.org> wrote:> On 2 June 2016 at 23:22, Rafael Espíndola <rafael.espindola at gmail.com> wrote: >> Because the patch includes way too much and doesn't explain what it is doing. > > So let me get this straight: someone publishes a patch, you don't like > it, you do some private investigations and commit whatever you want > without even notifying the original authors? > > I don't know how you work at your company, but this is not how open > source development works. > > This is not the first time either that you step over people's toes > with your "design decisions" that you don't share with anyone. Last > year, Adhemerval has worked for three months to get the LLD AArch64 > back-end working and out of the blue, no warning, the whole back-end > was yanked.lld is a very new project as far as linkers go. I am sorry we failed to get a perfect design the first time, but we did not. The symbol table was rewritten, the relocation processing was rewritten. And that was discussed. In fact, pcc did the final coding of the symbol table rewrite and rui review the relocation rewrite. The entirety of the project is subject to being rewritten as we find better ways of doing things. Cheers, Rafael
Rui Ueyama via llvm-dev
2016-Jun-03 00:53 UTC
[llvm-dev] [lld] r271569 - Start adding tlsdesc support for aarch64.
On Thu, Jun 2, 2016 at 5:21 PM, Renato Golin <renato.golin at linaro.org> wrote:> On 2 June 2016 at 23:22, Rafael Espíndola <rafael.espindola at gmail.com> > wrote: > > Because the patch includes way too much and doesn't explain what it is > doing. > > So let me get this straight: someone publishes a patch, you don't like > it, you do some private investigations and commit whatever you want > without even notifying the original authors? > > I don't know how you work at your company, but this is not how open > source development works. > > This is not the first time either that you step over people's toes > with your "design decisions" that you don't share with anyone. Last > year, Adhemerval has worked for three months to get the LLD AArch64 > back-end working and out of the blue, no warning, the whole back-end > was yanked. > > It doesn't matter if it was the right decision or not in the long > term, we don't just yank things, especially not before some > deliberation on the list. See how long is taking for the new pass > manager to be enabled, or FastIsel or the new Selection, or the new > register allocators, etc. > > That's not how open source works and I assumed you knew that. > > > > That is a general problem with aarch64, the documentation is missing > > and comments have to make due. I had a lot of work to rewrite the > > original aarch64 patches to be in line with the rest of lld and I > > didn't want to have to do the same for tls. > > You shouldn't be rewriting *any* patch, but asking the original > authors to do that themselves. > > There is a pattern that I'm seeing and that's that *you* refuse or > dismiss more patches than most other people. There are many of your > comments on reviews that are just personal, and then you step over > people's toes and commits yourself. > > This does not scale. But more importantly, it puts into doubt the > validity of the tool you're so hardly defending. > > You see, 3 years ago, I was asked to choose between MCLinker and LLD. > MCLinker was a linker for all purposes, but Chris Lattner convinced me > that LLD is the LLVM linker, and we should be focusing all efforts > there. > > It goes against the commercial interests of Linaro members to choose > such a premature technology, and it did put them back years of > development, because MCLinker was very close to ready, and MediaTek, > despite what people said, was very willing to accept our help. > > But in the interest of the community, and the open source nature of my > work, I have decided to pursue LLD and managed to convince Linaro to > put two people working on it. But now, I'm re-evaluating all my > strategy, and sincerely, I do not trust the LLD community anymore. >Not so fast to conclude that the community is not trustworthy, it doesn't consist of a single person or a single action. I do appreciate all developers who contribute to the project and want to foster the cooperative environment. As to the technical point, I honestly don't fully understand the particular patches in every detail, and since Rafael rewrote that part of code recently, I trust him that he is the most knowledgeable person who can make a best technical decision. Being said that, for this particular instance, I wouldn't submit right away but send it to review and explain why I think better. I'm totally fine if someone who knows more than me write a better patch than mine as a result of code review for my patch, but I would be surprised if an alternative is just submitted. I'm not sure if this needs to be reverted, but at least, could you send it review next time in a similar situation, Rafael?> The delay was because of the above mentioned issues. I wanted to make > > sure there was a solid foundation. > > Some patches are quick to review, others take 6 months. If you work in > open source you have *got* to understand that. If you're not willing > to take that cost, than please, refrain from working open source. > > > > Sorry, no. > > I understand your position, but you have to understand mine. I > therefore call into question your ability to care about such an > important project of the LLVM community. > > I sincerely believe that your actions are harming the project, and the > people trying to help. I appreciate the value of your contribution, I > really do, but if you don't change your way to handle open source > contributions, LLD will, whether you like it or not, become irrelevant > and be replaced. > > Such is the nature of open source. > > cheers, > --renato >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20160602/e272af1f/attachment.html>
Renato Golin via llvm-dev
2016-Jun-03 10:12 UTC
[llvm-dev] [lld] r271569 - Start adding tlsdesc support for aarch64.
On 3 June 2016 at 01:53, Rui Ueyama <ruiu at google.com> wrote:> Not so fast to conclude that the community is not trustworthy, it doesn't > consist of a single person or a single action.This is not an isolated incident. This seems to be the general behaviour around LLD, which is less so in the rest of the LLVM projects. The obliteration of the old ELF back-end was discussed only between a few people, not on the list. The technical reasoning could have been solid for a new back-end, but not for destroying fresh code. The removal was weeks after Adhemerval had LLD bootstrapping Clang on AArch64 upstream. There were backlashes to that decision, as well as other decisions in this list, and many people have already demonstrated discontent with how LLD patches and decisions are handled. During EuroLLVM's LLD presentation, a lot of people asked technical questions about the implementation of wanted features like library order, linker scripts, version scripts, and all answers were "it's not that hard, it's all in my head, don't worry about it". If this was a closed source project, and you, Rafael, Nick and PCC were the team developing it, it'd be expected that the team lead would have some leeway on the implementation and the consumers would have to wait until it's ready. But this is open source, and that's absolutely *not* how things work out here. That is *precisely* the problem, not this one incident. This incident was just the tipping point. That is why I personally don't trust the LLD community to act in the open source way. I have seen it consistently repeated over the last two years that I'm following. It makes no difference if this is a new project or not, this is open source, and in open source we work collaboratively. If you refuse people's patches because "you know better", you're not doing open source and people doing it will move elsewhere. This is not about you, me or Rafael, this is about the LLVM linker. So, I'll now be going back looking at MCLinker and see if we can make a Linux/BSD ARM/AArch64 upstream linker out of it, compatible with the GNU environment. As you can see [1], the development is still active, up-to-date with modern LLVM and there are ARM and MIPS support already, and the community there is far more receptive than LLD's. We'll continue to work on ARM and AArch64 patches to LLD, but if MCLinker proves an easier route to achieve our final goal, which is to have a Lesser-licensed open source ARM/AArch64 linker for GNU/BSD environments, and LLD's community continues to offer resistance and bad behaviour, we'll slowly de-phase LLD in favour of MCLinker, at least at Linaro. Such is the nature of open source. cheers, --renato [1] https://github.com/mclinker/mclinker
Rafael Espíndola via llvm-dev
2016-Jun-03 16:01 UTC
[llvm-dev] [lld] r271569 - Start adding tlsdesc support for aarch64.
> Being said that, for this particular instance, I wouldn't submit right away > but send it to review and explain why I think better. I'm totally fine if > someone who knows more than me write a better patch than mine as a result of > code review for my patch, but I would be surprised if an alternative is just > submitted. I'm not sure if this needs to be reverted, but at least, could > you send it review next time in a similar situation, Rafael?I honestly don't see what is the issue, so I don't think I be able to judge. The rule of the thumb for ahead of time commit is how confident someone is. I spend quite a few hours figuring out how tls works on aarch64 and as a result wrote a patch that used the same Expr names as the original patch. Really, diff both diffs and notice it is quite different. Also notice that the commit message includes information about aarch64 that I simply haven't seen written anywhere, including the original patch. Once more is implemented I will document the details I found on how dlopen works. Cheers, Rafael