[llvmlinux] LLVMLinux Meeting 2013.07.17

Behan Webster behanw at converseincode.com
Sat Jul 27 03:00:58 UTC 2013


*

Sorry this took so long to send out.

LLVMLinux Project: http://llvm.linuxfoundation.org/


<http://llvm.linuxfoundation.org/>

This week the meeting was on Wednesday, July 17 2013 on Google Plus 
Hangout at 16:00 
UTC.<https://www.google.com/calendar/embed?src=su5vu85fj58ncfrgalmq4vbbf0%40group.calendar.google.com&ctz=GMT>


<https://www.google.com/calendar/embed?src=su5vu85fj58ncfrgalmq4vbbf0%40group.calendar.google.com&ctz=GMT> 


If you haven't use G+ Hangouts before, make sure you have the 
appropriate Chrome or Firefox plugin installed, and tested before the 
time of the meeting. You can try a test hangout with me today before the 
meeting if you want to. G+ recently changed, so hopefully that won't be 
an issue for our meeting.


-------------------------------------------------------------------------------------------------------------------------

Previous meeting's top 2-3 work items:

  *

    This is what people said they'd be working on at the end of the last
    meeting:

      o

        Behan

          +

            Upstream kernel patches

          +

            VLAIS article

      o

        Eduard

          +

            If clang -### bug solved: ensure cross-compile (=check) to work

          +

            Get kbuild's checking framework to work with checker
            =ccc-analyzer)

          +

            Make initial selection on checkers to run by default

      o

        Tinti (after July, 10th)

          +

            Add Nexus 7, Nexus 4 and Raspberry Pi to patch triage

          +

            Upstream Nexus 7 issue (ldrexd)

              #

                Test http://llvm-reviews.chandlerc.com/D1084

          +

            Add GDB tutorial on Wiki

          +

            Add KGDB tutorial on Wiki

          +

            Add U-Boot

      o

        Jan-Simon

          +

            Finish up x86 buildbot

          +

            Follow-up / review btc

-------------------------------------------------------------------------------------------------------------------------

Agenda for this week:


  *

    (5 mins total) Everyone shared a quick summary of the progress
    they've made from the last 4 weeks

      o

        Behan

          +

            Updates to the build system

          +

            Working on llvm/clang breakage on mainline

          +

            Patch review

          +

            BeagleBone updates

      o

        Eduard

          +

            Kbuild's $CHECK framework now working

          +

            Initial documentation for behavior pushed

          +

            Checker selection ongoing (compile times are LONG)

      o

        Jan-Simon

          +

            x86 bot (nightly) online

          +

            x86_64_tiny

          +

            Update to build system

          +

            tracking down llvm/clang breakages

  *

    (45 mins) General meeting discussions:

      o

        Mailing list usage

          +

            Recently there has been a lot more traffic on the mailing
            list, which is great

          +

            Everyone is encouraged to discuss things on the mailing list
            whenever possible

          +

            Discussing things on the mailing list brings more people
            into the conversation, and makes sure more people are up to
            speed with what is happening

      o

        LLVM update (current wish list)

          +

            Native and prebuilt support was added to the build system

          +

            The prebuilt clang is being downloaded from llvm.org

          +

            The decision during this meeting was that for the time up
            until Linux Plumbers people should use LLVM/Clang v3.3 and
            concentrate on upstreaming kernel fixes where ever possible.
            Since kernel developers can now use a stock compiler, it's
            important that we get the kernel patches into mainline.

          +

            This doesn't mean that people can't work on LLVM/Clang, just
            that the focus has moved from Clang to the kernel

          +

            Latest SVN/git Clang+LLVM is broken for ARM

          +

            Clang+LLVM for x86_64 is having SSE issues in Real mode at
            boot time

          +

            v3.3 works for ARM and x86_64

      o

        Linaro Connect

          +

            Renato attended Linaro Connect

          +

            He was asked a lot of questions about compiling Android with
            Clang, and for features to make that easier

          +

            Although he still can't directly help the project, his work
            surrounding this area indirectly supporting the LLVMLinux
            project goals surrounding the adoption of Clang in the
            development community

      o

        Kernel Patch triage (highest priority now)

          +

            This should now be the focus of our combined efforts

          +

            If patches aren't strictly necessary for the kernel to run
            with clang, they should be set aside for now

          +

            Patches which remove false positive warnings should be kept
            in. Kernel devs don't want to see any unnecessary compiler
            noise.

          +

            The best way to participate in upstreaming patches is with
            the following spreadsheet. Ask for access if you want to be
            able to update it

          +

            https://docs.google.com/spreadsheet/ccc?key=0Ao2VHhaw1DTqdERLUDBmVlpiY2pUNUlLa1k3ck1Zc1E#gid=0

          +

            Spreadsheet integrates with "make kernel-patch-status" in
            LLVMLinux build

      o

        Merged globals/section mismatches update

          +

            Still needs more investigation

          +

            Investigation so far
            https://lftraining.dyndns.org/pad/p/llvm-section-mismatch

          +

            These dropped attributes mess up where init and exit code is
            linked which is causing the section mismatches

      o

        Tools

          +

            Clang Static Analyzer

              #

                Demo checker run:
                http://buildbot.llvm.linuxfoundation.org/2013-06-17-1/

              #

                Still full of false positives. Will publish more widely
                when it's less noisy (Eduard is working on removing
                checkers which are useless to the kernel code base)

              #

                A current x86_64 checker build takes about 4 hours on
                Eduard's laptop

              #

                Some changes are needed for the LLVMLinux build system -
                mostly done

              #

                Still having issues with ARM cross compile with static
                analyzer (but this will work eventually. Upstream bug.)

              #

                Adding an optional buildbot build of the kernel with checker

              #

                Disable some checks (which are only valid for user space)

              #

                Write custom checks for the Kernel

                  *

                    Can get ideas from other analysers (coccinelle,
                    smatch, sparse)

                  *

                    Marcelo suggested looking here
                    http://dl.acm.org/citation.cfm?id=1950401

      o

        Raspberry Pi Update

          +

            Building and booting again (was broken recently)

          +

            USB hub driver is still broken

      o

        Cubieboard

          +

            forward ported patchset (cubieboard overlay)

      o

        LLVM micro conference at Linux Plumbers Conference

          +

            Mark and Behan were asked to lead the LLVM Micro-conference
            at Linux Plumbers Conference

          +

            http://wiki.linuxplumbersconf.org/2013:llvm

          +

            New link for submitting proposals to micro conference

          +

            http://www.linuxplumbersconf.org/2013/ocw/events/LPC2013/proposals

          +

            No update this week

      o

        Review bug list (please update your bugs on the website before
        the meeting)

          +

            No change this week

      o

        Review todo/roadmap list  (please update your todos on the
        website before the meeting)

          +

            No change this week

      o

        Review the project Roadmap/Timeline

          +

            https://docs.google.com/a/converseincode.com/spreadsheet/ccc?key=0AoeRmB6JBVt_dGYwSUNNNHd2SFFMWF9yMTRoa2VuZmc#gid=0

      o

  *

    (5 mins) Each meeting attendee listed the top 2 items to be worked
    on for the next 2 weeks

      o

        Behan

          +

            Remove make_kernel.sh

          +

            Concentrate on upstreaming kernel patches surrounding clang
            and kbuild

          +

            Upstream ARM patches where possible

      o

        Eduard

          +

            Make final "initial" selection on checkers

          +

            Bring code into state ready for merge

              #

                Do merge after review

      o

        Jan-Simon

          +

            Upstream x86 boot blockers (based on Kernel HEAD and
            clang/llvm v3.)

          +

            unbreak x86 buildbot

          +

            Fix build breakage on x86 (llvm/clang/head).

      o

        Tinti

          +

            Postponed for next meeting.


Next meeting in 2-ish weeks. doodle poll to follow.

*

-- 
Behan Webster
behanw at converseincode.com

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxfoundation.org/pipermail/llvmlinux/attachments/20130726/507e3655/attachment-0001.html>


More information about the LLVMLinux mailing list