On 3 June 2016 at 17:10, Rafael Espíndola <rafael.espindola(a)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
== Progress ==
- Holiday Monday/Tuesday
- Finished writing initial support for ARM in lld. Posted upstream as
RFC, no comments so far.
- Implemented, but not tested the static Thumb relocations present in
the arm-linux-gnueabihf-gcc
-- I'd forgotten how much I hated the Thumb 2 instruction encodings.
== Plan ==
- Add tests for Thumb relocations
- Start thinking about how interworking can be implemented in lld
* Monday off [2/10]
# Progress #
* TCWG-518, arm linux range stepping. [4/10]
Finished V2, and send them out for review.
More bugs in existing GDBserver are found, fixed them as well.
8 patches become 12 patches.
* Upgrade linux kernel on chromebook to verify Russell King's ptrace
fix.
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-May/431972.html
[3/10]
This may be the cause of unstable result of GDB floating point tests,
and they are tracked by GNUTOOLS-4858.
4.6.1 is running on chromebook now, but haven't try the patch yet.
* TCWG-547, "align software single step in other targets with arm's
implementation".
Patches are pending for review. Pinged Pedro to give a review.
* Misc, [1/10]
** Commit fix to PR 19998, and review the follow-up patch.
** meeting and training,
# Plan #
* TCWG-518, TCWG-547, TCWG-333
--
Yao
== Progress ==
* Remove exit-on-error flag from CodeGen tests [TCWG-604] [4/10]
- This is a follow-up of TCWG-592: when changing the diag handler,
some of the tests started to fail, so we had to add an exit-on-error
flag to preserve the old behaviour until we can fix the tests.
- Patch fixing the MIR tests (PR27770) - still in upstream review
- Submitted another patch fixing two other BPF tests (PR27768/9) -
committed upstream
- Submitted a patch fixing one of the AMDGPU tests (PR27761) - in
upstream review
- Investigating the ARM test (PR27765)
* Use git worktree in llvm helper scripts [TCWG-587] [4/10]
- In review, hopefully we can wrap it up soon
* Misc [2/10]
- More LLVM backend education (MI level), ARM ARM etc
== Plan ==
* Remove exit-on-error flag from CodeGen tests [TCWG-604]
- Fix the ARM test
* Use git worktree in llvm helper scripts [TCWG-587]
- Fix a regression in the error-handling
- Address review comments
On 2 June 2016 at 23:22, Rafael Espíndola <rafael.espindola(a)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
On 2 June 2016 at 20:49, Rafael Espindola via llvm-commits
<llvm-commits(a)lists.llvm.org> wrote:
> Author: rafael
> Date: Thu Jun 2 14:49:53 2016
> New Revision: 271569
>
> URL: http://llvm.org/viewvc/llvm-project?rev=271569&view=rev
> Log:
> Start adding tlsdesc support for aarch64.
>
> This is mostly extracted from http://reviews.llvm.org/D18960.
Rafael,
Why commit part of Adhemerval's patch without reviewing his request?
This is a really serious breach of community trust.
Not only we're waiting for reviews on the TLS set of patches and
having to rebase every two weeks, but now you implemented in a way
that wasn't discussed on the review, didn't mention authorship, nor
asked Adhemerval for any input.
If you had technical input on his patch, you should have done on the
review. If you wanted him to split in smaller patches, you should have
asked on the review and let *him* do it.
Even if you were the code owner (which you're not), it would still be
a *serious* breach of trust and respect.
I hereby respectfully request that you revert your patch and let
Adhemerval finish the work that he started in the way that we normally
do in the LLVM community.
regards,
--renato
* Off on Friday [2/10]
# Progress #
* TCWG-518, V1 got reviewed, and working on V2. Two existing bugs in
GDBserver are found, and fixed. Testing them... [4/10]
* Upstream patches review, all of them are about GDB python. [2/10]
* Respond to Jim Wilson's question on AIX GDB build failure caused by
his binutils patch for AArch64. Confirm that GDB build fail after
his patch. [1/10]
* Misc, [1/10]
# Plan #
* Bank holiday on Monday,
* TCWG-518, get V2 ready for review,
* Ping TCWG-561 and TCWG-547,
--
Yao
=== This Week ===
Resolved TCWG-231 (LLDB bring up and bug fixing on HiKey 96Board)
[TCWG-231] [1/10]
-- Ran tests on AArch64 LLDB tests on HiKey and compared with Nexus 9
test results.
-- Less than 1% difference in test results and good pass rate found.
LLDB ARM: Bug fixes, integration and testing on various ARM platforms
[TCWG-228] [2/10]
-- Progressed towards resolution.
-- Prepared close out setting up RaspberryPi2, RaspberryPi3, Hikey and
Chromebook as testers.
-- Compiled armhf test results.
LLDB Chromebook Test Stability [TCWG-563] [2/10]
-- Some further investigation on llvm-chrome-06 test failures.
-- Marked and committed some xfails and reported relevant bugs if not
already logged.
Support for watchpoint un-alligned watchpoint addresses on LLDB
AArch64 [TCWG-367] [1/10]
-- Debugging of watchpoint handling code and tried out instruction decding.
LLDB buildbot updates and maintenance [TCWG-241] [2/10]
-- Improved tester script to initiate lldb-server inside a chroot.
-- Monitored buildslave stability and
Miscellaneous [2/10]
-- Meetings, emails, discussions etc.
-- Migrated laptop to Ubuntu 16.04
=== Next Week ===
LLDB Chromebook Test Stability [TCWG-563]
-- Final words on watchpoint issue on llvm-chrome-06
-- Submit updated makefile.rulez for LLDB tests.
-- Report remaining bugs and commit xfails upstream.
Support for watchpoint un-alligned watchpoint addresses on LLDB
AArch64 [TCWG-367]
-- Implement instruction decoding for watchpoint hit detection.
A look into kernel code used by Nexus android devices failing
watchpoint support [TCWG-622]
Miscellaneous
-- Out of office on Tuesday 31st 2016 for visa documents preparation.
* ! day off (2/10)
== Progress ==
o Extended validation (2/10)
- Benchmarking comparison script on-going
- Reproduced armhf schroot slowness on AArch64 Debian Jessie
No issues when using Ubuntu (Trusty and Xenial).
o Upstream GCC (4/10)
- Started ARMv8.1 libatomic support
(environment setup, code understanding, ifunc support analysis)
o Misc (2/10)
* Various meetings and discussions.
== Plan ==
o Continue libatomic work
