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Lu Yahan edited this page Dec 24, 2020 · 43 revisions

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)[https://github.com/v8-riscv/v8/wiki/media/add_rvv.pdf]
    • 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  • Review open issues and close or update outdated ones (all)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/v8-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

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