Meeting 2024-10-29

• Team calendar

  • Next on Necko triage: Randell 

• New contributors / Friends of Necko THANK YOU!!

  • None in the last week. 

• Round Table

  • – enter public topics –  

• Active Projects roadmap Fx132 rel Oct 29, Fx133 rel Nov 26, Fx134 code freeze Nov 21 

  • Firefox Essential Internal Services Toughening[FEISTY]

    • [Greg] Passed internal review, now in strategic review

  • DoH Enablement - Fenix and Focus

    • [Greg] Passed internal review, now in strategic review

  • 3rd Party Cookie Deprecation (in progress, target Fx134)

    • 3PCD timeline

      • 131: Enable in nightly all windows(dry run)

        • Check back once 131 hits release and see the telemetry

      • 132: Enable in PBMode and ETP Strict to release 

        • Tracking breakage 

      • 133: Release telemetry on partition limit will start, review it (we are here)

        • – enter updates –

      • 134: All windows in release (targeting January)

      • 136: “Migration”/deletion of TCP cookies (non-chips partitioned)

    • [Ed] Ongoing investigations and discussions with privacy team for google-auth followup

  • Fetch keepalive: (riding the trains, Target Fx133) 

    • – enter updates – 

  • HTTP Priorities Experiments (riding the trains, target Fx 132)

    • [Greg] Released today closing!

    • [ACreskey] First experiment that selects only pages that don’t make use of fetchpriority (images). Promising results

      • https://protosaur.dev/perf-reports/fetchpriority-nightly_only_docs_with_fetchpriority_images.html#All-lcp_time

      • 2.6% improvement in mean lcp, up to 7% at P80

      • Following up on Fenix (nightly) and Desktop (beta)

    • [skim working on:]

      • 1926407 - Consider modifying the fetchpriority adjustments for so that priority="high" is given a higher priority than auto

  • Firefox/Chrome benchmark test suite (in progress, Fx132)

    • First cut of download results: https://lookerstudio.google.com/reporting/f5fbaacd-a473-4daf-bf22-faa3d3c8391f/page/DO9EE

    • Needs validation, maybe hand testing 

    • Related: Chromium’s loadline framework

      • https://chromium.googlesource.com/crossbench/+/refs/heads/main/config/benchmark/loadline

    • (greg) Perf Infra Hardware review Performance Hardware Review

    • – enter updates –

• Interop 2024 URL (in progress, target H2 2024)

  • [Ed] Landed Add defaultUri bypass and Enable defaultURI 

  • URL interop score moves to 99.3% of our commitments (96.8% if we consider all of URL test scores)

• necko-glean: (sekim) Landing glean patches using #ifndef ANDROID blocks tracking such blocks using Bug 1901798  

  • – enter updates –

• Fast UDP I/O in Firefox (in progress, target H2 2024)

  • milestone 1 - basic end-to-end integration

    • On Android x86 Focus and Fenix CI startup tests have failed due to a seccomp panic after a `recvmmsg` call.

      • Upgrade mozilla-central to quinn-udp v0.5.6 ready for review.

        • Upgrade was previously blocked due to version conflict in transient depedency, namely windows-sys v0.52.

        • After larger discussion, we found a solution not involving upgrading many crates in the Rust ecosystem.

  • milestone 3 - Benchmark result for download and upload

    • Add 100 MiB upload benchmark to Neqo CI.

    • Optimize neqo-client send path for more accurate benchmark results.

    • Simulating gbit link up- and download via Neqo network simulator.

  • milestone 4 - multi-packet IO

    • Lars' quinn-udp pull request merged, adding experimental multi-message support on Apple platforms.

    • Adjusted quinn-udp benchmark to measure GSO, GRO and recvmmsg performance.

  • milestone 5 - multi-packet state machines

    • Pull request stack, removing major allocations in Neqo UDP receive path is merged.

    • Mozilla-central upgrading to latest release (v0.10.0) containing the optimization happening in phabricator#D226823.

    • Minor follow-up for the Neqo test server is pending.

  • Identify where bottlenecks are is it GSO or other

• Implement WebTransport based on HTTP/2

  • – enter updates –

• Performance work: 

  • [acreskey]

    • Expecting to start these four experiments tomorrow

      • https://mozilla-hub.atlassian.net/wiki/spaces/FIREFOX/pages/11047744/Experiments+Necko#Schedule

        • https://experimenter.services.mozilla.com/nimbus/fetch-priority-fenix-nightly/summary (Fenix nightly)

        • https://experimenter.services.mozilla.com/nimbus/fetchpriority-beta-pageload-event/summary (Desktop beta)

        • https://experimenter.services.mozilla.com/nimbus/performance-metric-calibration-with-lcp-nightly/summary (A/A/A/A on Desktop nightly)

        • https://experimenter.services.mozilla.com/nimbus/fenix-performance-metric-calibration-beta-followup/summary (A/A/A on Fenix beta)

    • Based on Randell’s profiling of main thread, ran this test and logged this one:

      • Bug 1927538 -  URL Classification can delay AsyncOpen-to-transaction-pending by 26-25%, visual metrics by 3-10% in raptor pageload test

    • Great help from Sean Kim:

      • 1926407 - Consider modifying the fetchpriority adjustments for so that priority="high" is given a higher priority than auto

      • Network Marker Profiler upgrades

        • Bug 1915717 -  [network-markers] Expose http protocol version for a request in the profiler network tab

        • Bug 1919148 -  [network-markers] Expose class of service for each request in the profiler network tab

  • [sunil]

    • OnDataFinished and OnStopRequest probes indicate we still experience delays in between dispatching and running OnDataFinished in the background thread. 

    • Did local browser tests to confirm this. ChannelEventQueue design seems to be a possible bottleneck. Will investigate further this week.