Date: 3/17/2021

Agenda

  • Announcements

  • Community updates

  • Upstreaming updates

  • Action item follow-ups

  • Open PR Discussion

  • Presentations for any recent/planned developments

Minutes

  • Announcements

    • Initial commits have been merged

    • Sparkplug patch has been commited

    • Work on node.js has been started and initial builds have passed

    • v8 repo has been moved under riscv/v8

  • Community Updates

    • Managed runtimes group (java specific) sent out call for chair and co-chair

    • RISC-V foundation has setup a basic infrastructure for the specification and software

    • There is talks about setting up a group for performance modeling and performance profiling tools

  • Upstreaming

    • still waiting to get a proper privilege to thumbs up code.

Action Items

  • Changes to the CI in regardes to the master, riscv64, and riscv64-dev branches

  • Addition of architecture flags for compilation

Other

  • Working with RISC-V International to get internship positions for v8.

Date: 3/3/2021

Agenda

  • Announcements

  • Community updates

  • Upstreaming updates

  • Action item follow-ups

  • Open PR Discussion

  • Presentations for any recent/planned developments

Minutes

  • Announcements

    • The initial support of SparkPlug for RISC-V is [done] (https://github.com/riscv/v8/tree/riscv-sparkplug-dev)

    • tensorflow.js can run a the simple [demo] (https://www.tensorflow.org/js/tutorials/setup) on the [RISC-V node.js] (https://github.com/riscv/node/)

  • Upstreaming

    • still waiting to get a proper priviledge to maintain and review+ the RISC-V arch files

  • Other updating

    • [Test status] (https://github.com/riscv/v8/wiki/Testing-Status) in wiki page is updated.

    • The github issue and prs had been reviewed and cleaned up

    • C-ext support can run benchmark

Action Items

  • check and fix issue #53, #166, #297, #403, #414

  • test result for SparkPlug

  • moving on of C extension merge and evaluate

Date: 2/17/2021

Agenda

  • Announcements

  • Community updates

  • Discuss workflow after upstreaming (#442)

Minutes

  • Announcements

    • The Chromium team has released SparkPlug:

      Sparkplug is a new baseline, non-optimising second-tier compiler, designed to fit in the compiler trade-off space between Ignition and TurboProp/TurboFan.

  • Community updates

    • Chairs for all RISC-V task groups are in a renominating process

    • RISC-V is holding several Forums in April and May - Events

    • RISC-V has some time slot at ISC

    • Software has two new TGs

      • Performance modeling tools

      • Performance profiling and monitoring tools

    • RISC-V is pushing extension/ISA groups to ensure that there are no encumbered (patents, copyrights) items in their proposals

    • Brice is working with Sanhong from Alibaba on a charter for the Managed Runtimes group

      • Will share with the team for input (on Slack)

    • It seems progress on JDK upstreaming is very slow

  • Upstreaming status

    • Yahan and Brice now have access to start trybots for our Gerritt reviews

      # start default trybots
git cl try
# start RISC-V trybots
git cl try -B luci.v8.try -b v8_linux64_riscv64_rel_ng

    • Brice requested port committer status for some of us, so that we may apply the “Code-Review +1” label (equivalent of a LGTM)

      • Waiting to hear back on that

      • We will need to wait for a full committer to approve changes for now

  • Discuss workflow after upstreaming (#442)

    • We will plan to make changes in our GitHub repo (this one), do our own code reviews here, then open upstream pull requests on Gerritt

    • If others submit changes upstream, we should review them, and also encourage the developers to join our group

    • How should we keep up-to-date with upstream?

      • Mirror upstream into master branch automatically

      • Run our regression tests on master to quickly identify problems caused by upstream changes

      • Rebase riscv64 branch regularly on to master

    • Brice will create a wiki page to describe the process of how we should stay in sync with upstream and the process that developers should follow to start new work

    • Qiuji will triage the issues from upstream and assign them to the team as needed

  • Derek suggested pushing the C extension changes without jumps as a separate pull request

    • Agreement from the group

Action Items

  • [ ] Create wiki page to describe new process for working with upstream - Brice

  • [ ] Open merge request for C extension (without jumps) - Derek

Date: 1/20/2021

Agenda

  • Announcements

  • Community updates

  • Upstreaming updates

  • Action item follow-ups

  • Open PR Discussions

  • Presentations for any recent/planned developments

  • Miscellaneous

Minutes

  • Community Updates:

    • There will be a RISC-V retreat on 1/27/2021 and 1/28/2021 Beijing time. Derek and Chao will showcase running V8 on PicoRio hardware.

  • Upstreaming Updates:

    • Current rebase has some build failures.

    • The planned current PRs that will be pushed in to master will be #379, #384, #393.

    • Let Brice know if there are any PRs you would like to be added.

  • Updates from Wei about RVI meetings:

    • There are plans for a performance tracking system on the compiler side.

    • There will be another bi-weekly meeting 1/21/2021 afternoon Beijing time. Wei will update us on what he learns there.

    • J-Extension group work is currently focusing more on security.

  • Miscellaneous

    • In future meetings we will be moving presentations to the start.

    • Wei would like to test using Qemu’s User Mode for increased regression testing speeds.

Action Items

  • upstreaming: fix build issue and push in PRs.

  • Setup PTS for V8 (@ww)

  • Test Qemu’s User Mode (@ww)

  • Continue c-ext support work(@Derek Tu)

Date: 1/7/2021

Agenda

  • Announcements

  • Community updates

  • Upstreaming updates

  • Action item follow-ups

  • Discussion about the Wishlist 2021 for V8 for RISC-V project

  • Present recent develop progress status if any(RVV-Wasm support, Performance analyze vs ARM64 etc.)

Minutes

  • Upstreaming issues:

    • need to separate RV32 modifies from the current RV64 modifies(apply to Georg Neis’s comments)

  • Updates from Wei about RVI meetings:

    • PLCT will set up the Performance Tracking System(PTS) for the Code speed group. V8 will be the first one put to the target software.

  • Action items follow-ups:

    • issue370 need to be checked with OS guys to see how to flush icache for JIT.

    • issue 372/373/375/376/378 need to be clarified(low priority)

    • pr309 need to be closed. pr379 need to be reviewed

  • Wishilist for 2021 is discussed and priority confirmed:

    • upstream(1st)

    • node.js support(2nd)

    • wasm and JS speedup(3rd)

    • ISA extension support(4th)

  • Yahan introduced progressing for Wasm-RVV. He adds new register type declaration for the non-overlayed vector registers.

  • Qiuji reported some result for performance evaluation of V8-RISCV. The result is comparing to ARM64.slides

Action Items

  • upstreaming: apply to Georg Neis’s comments

  • clean up github issues and prs:

    • issue370(@qiuji)

    • pr309(@taoliqiang)

    • pr379(@luyahan)

    • issue 372/373/375/376/378(@luyahan & @qiuji)

    • issue258 (give a investigate report to it @qiuji & @taoliqiang)

  • Setup PTS for V8 (@ww)

  • Re-start c-ext support work?(@Derek Tu)

Date: 12/23/2020

Agenda

  • Announcements

  • Community updates

  • Upstreaming updates

  • Action item followups

  • Review open PRs and determine next actions

Minutes

  • We will start rotating hosts for the meeting between PLCT, RIOS, Peng, and Futurewei

    • PLCT lab will host the next one

  • Updates from Wei about RISC-V International meetings

    • Code speed group is approved

    • Performance tracking task group will define scripts to run benchmarks and post results to a website

    • Plan to build Java and JS speed task groups

  • Yahan shared a roadmap for adding the V extension support to V8 slides

    • Defined 2 phases: prepare and implement

    • Discussed timing and testing of this work

    • Probably a subset of the V extension will be sufficient to support the WebAssembly instructions, so be sure to focus on this first

  • Brice completed the release of the RPMs

    • We may want to trigger releases for specific tags in addition to the LATEST

    • Perhaps use a special prefix

  • Derek announced that RIOS will hold a student led summit on Jan 20 where he will demonstrate V8 on a PicoRio

    • He will pause work on the C extension until after this

  • Wei discussed setting goals for 2021

    • Speed up V8 on RV64GC

    • Support V extension, C extension, B extension

    • Node.js

    • Peng brought up real world usage, including browser, ML (tensorflow.js)

  • After upstreaming, we will need to update our workflow

    • Will likely need to keep branches for unratified extensions in our repo, not upstream

Action Items

  • Review open issues and close or update outdated ones (all)

  • Review open PRs and rebase or address open comments (Nekhlyudov, Yahan, Derek, Liqiang)

  • Provide some input to Wei about goals for 2021 (Peng, Reza, Brice)

Date: 12/09/2020

Agenda

  • Announcement

  • V8 re-base update and outstanding issues (Brice)

  • RISC-V community news (Wei)

  • Follow-up from the last meeting

  • Technical presentation: register allocator study (Qiuji)

  • Open discussions

Action items

  • Setup GitHub Actions to add release builds - @Brice

  • Give Qiuji code review permission - @Brice

Date: 11/11/2020

Agenda

  • V8 re-base update and outstanding issues (Brice)

  • RISC-V community news (Wei)

  • Follow-up from the last meeting

  • Technical presentation: J-extension group pointer-masking proposal and analysis on V8 (Peng)

  • Open discussions

Highlights

  • On the pointer-masking discussion, the intuitive feeling is that V8 (a managed runtime w/ already a lightweight isolation mechanism) may not be a good candidate for pointer-masking (i.e., because the software solution already provides pretty good isolation protection, and using a HW solution is a lot more rigid). We decide to be more explicit in voicing this opinion to the J-extension workgroup.

Action items

  • Add a release wiki page on how people can gain access to pre-built v8 binary

  • Give a presentation on the algorithm to extend V8 register allocator for C-extension instructions (qiu ji)

Date: 10/28/2020 6pm PT

Agenda

  • Announcement

  • V8 re-base update (Brice on new problems discovered and outstanding issues)

  • Follow-up from the last meeting

  • Technical presentation: how does V8’s register allocator work? (Derek & Liqiang)

  • Technical presentation: how to support C-extension instruction code gen (Reza)

  • Technical presentation: preliminary performance analysis (Wei)

  • Technical presentation: J-extension group pointer-masking proposal and analysis on V8 (Peng) [if time permits]

  • Open discussions

Action Items

  • Participate in the code-speed workgroup meetings (Wei, Brice, Peng)

  • Give a presentation to compare the J-extension proposal and V8’s compressed-pointer implementation (did not have time to cover this week, Peng)

  • Setup 3rd party package distribution of our cross-compiled V8/Node binary (carried over from the last meeting, Wei)

  • Write up the next steps for the register allocation study for Liqiang & Derek (Peng)

  • Share today’s slides to repo wiki (https://github.com/riscv/v8/wiki/Content-sharing) (liqiang, reza, yahan)

  • Present the lgorithm to extend V8 register allocator for C-extension instructions (liqiang, reza, derek)

Date: 10/14/2020 6pm PT

Agenda

  • Announcement (J-extension group)

  • V8 upstream update (Brice: rebase, cpid, using gcc tool-chain)

  • Follow-up from the last meeting

  • Additional C-extension support discussion (Peng et al)

  • Open discussions

Highlights

  • Wei updated us the recent reorg/changes in RISC-V international taskgroup organization, there may be opportunities for us to take some initiatives or participate in other workgroups

  • Discussed how to generate C-extension instructions in macro-assembler: may need to teach register allocator to generate instructions that satisfy constraints of C-extension instructions (i.e., smaller groups of registers and reusing 1st operand as destination register)

Action items

  • Update testing status for this week (Wei)

  • Attend code-size optimization workgroup (Peng, Wei)

  • Add a wiki page to summarize how our codebase satisfies the upstream criteria (Brice)

  • Give a presentation to compare J-extension proposal and V8’s compressed-pointer implementation (carried over from last week, Peng)

  • Setup 3rd party package distribution of our cross-compiled V8/Node binary (carried over from last week, Wei)

  • Give a presentation on how V8 register allocator works (Liqiang and Derek)

  • Define milestone for this month, especially define the performance analysis requirement (Peng)

  • Give a presentation on benchmark performance comparison between RISC-V and MIPS64 (Wei?)

  • Create issues for the next steps of C-extension implementation and assign (Peng)

Date: 09/30/2020 6pm PT

Agenda

  • Follow-up from the last meeting

  • Open discussion

Highlights

  • Many test failures are resolved compared to status of two-weeks ago

  • We discussed how to find a reasonable path to distribute V8/Node binary to end-users

Action items

  • Check w/ V8 team whether building w/ LLVM is a requirement for upstream (Peng)

  • Define exactly what needs to be done to solve the tools dependency for native build (required by both Debian and Fedora) and open an issue to track it (Brice)

  • Setup a 3rd party package distribution of our cross-compiled V8/Node binary (Wei)

  • Present a comparison of J-extension’s pointer-masking proposal and V8’s compressed pointer feature (Peng)

Date: 09/16/2020 6pm PT

Agenda

  • Announcement (V8 global forum talk, V8 upstream prep)

  • Follow-up from the last meeting

  • Update on CI and Node native build (Brice)

  • C-extension support discussion (Peng et al)

  • Open discussion

Highlights

  • Finally, CI is restored

  • Cross-building of NodeJS is streamlined, script in the repo, instruction on the wiki

  • Agreed on the partition of C-extension support among Chao, Derek, Liqiang, and Thomas

Action items

  • Prioritize failures exposed by release and stress-opt and identify critical ones (Peng, carried from last week)

  • Discuss w/ Fedora team members on the next steps to resolve dependence on other tools (cipd, etc) (Brice)

  • Investigate style guide and other requirements for V8 upstreaming (Brice)

  • Open an issue on generating optimized codes for atomic constructs (Peng)

  • For bi-weekly testing status update on the wiki, add the delta compared to the previous report (Wei)

  • For the comprehensive CI tests (after a PR is approved), if there is regression, report it on Slack and notify owners of the PRs involved (Wei)

Date: 09/02/2020 6pm PT

Agenda

  • Follow-up from the last meeting

  • 09/04 milestone summary(latest testing status) (Peng et al)

  • Monthly milestones for 09/07 ~ 10/09

Discussions

  • Agreed on Sept-October milestones: focus on V8 upstream, get started on performance work

Action items

  • Enable external CI cloud instance (Wei expects to complete by next Monday, otherwise pass WIP PR to Brice)

  • Send instructions on how to run Node tests to Brice (Yahan)

  • NodeJS setup (carried over from last meeting, Yahan/Brice)

  • Automate generation of testing status and add release build results for QEMU/HiFive next time (Wei)

  • Prioritize failures exposed by release and stress-opt and identify critical ones (Peng)

Date: 08/19/2020 6pm PT

Agenda

  • New attendee introduction & announcement

  • Follow-up from last meeting

  • Technical content: how to debug v8 (Brice) - slides

  • 09/04 milestone progress (latest testing status) (Peng et al)

  • Open discussion: optimizations (all)

Discussions

  • Heads up on September goals: optimization, C-extension, V8 upstream, v8-riscv release

  • Optimization: two tracks 1) development track will focus on low-hanging performance optimizations (e.g., constant pool, function prologue/epilogue optimization, improve codegen in TurboAssembler and code-generator), 2) performance track will do some performance analysis on benchmarks (e.g., compare against MIPS64) and tools development

  • C-extension discussion: 1) RISC-V is a custom modular ISA, how to detect which extensions are supported by the hardware (deal w/ the ISA fragmentation and complexity); 2) estimate the code-size benefit of C-extension

Action items

  • Enable CI on external cloud instance (need to send the result back to github via REST API) (Wei)

  • Setup NodeJS repo under V8 (Brice)

  • PLCT team sign Google CLA (Wei)

  • Capture all qemu & HiFive board failures into issues (Wei)

  • Include release build in QEMU and HiFive runs (Wei)

Date: 08/05/2020

Agenda:

  • New attendee introduction

  • Follow-up from last meeting

  • August milestones & project operation (Peng)

  • Cross-compiled and native build progress (Wei et al)

  • Work-group status update (all)

Discussions:

  • Github wiki and RIOS documentation site: 1) Wei mentioned that RTS and markdown can be intermixed in documents, need to figure out whether it is possible to have markdown document working w/ RIOS’s RTS documentations; 2) find tools to automatically convert from markdown to reST format

  • RISCV32 support: Wei’s team has experimented with building 32-bit V8 on Yocto/OpenEmbedded and encountered major toolchain issues (gdb and gcc?)

Action items:

  • Resolve the synchronization of the github wiki and RIOS documentation site (Ye)

  • Run simulated build failures in real hardware to see if they also fail in real hardware (Wei)

  • Set-up a mechanism to update testing status wiki (simulated, qemu, HiFive) with latest results before the bi-weekly developers’ meeting (Wei)

  • NodeJS demo video fro Global Forum talk (Yahan & Brice)

Date: 07/22/2020 (6pm PT/9am Beijing)

Agenda:

  • Brief introduction of participant (all)

  • Information sharing (Peng et al)

  • Github/Slack operation rules (Brice)

  • Testing status for simulated build (Peng)

  • Introduction of work-groups (Peng)

  • Suggestions & discussions (all)

Information sharing:

  • Our talk proposal was accepted to RISC-V Global Forum (September)

  • Got feedback towards v8 upstreaming: our simulated build testing results are quite promising, suggest to do additional stress-test on compiler and optimization, release-build tests, and run the performance suite

Action items:

  • Define milestones for early September (Peng)

  • CI efficiency issues not fully resolved, need help from anyone w/ experience of setting up CI (?)

  • Address permissions of adding labels or re-assign issues (Brice)

  • Wei’s team present cross-compiled build status next time (Wei)

  • Resolve how to setup wiki repo that is most convenient to us (Ye, Brice, Peng)

Find uploaded materials from all meetings here