I'm guessing the root cause is this: --- /b/s/w/ioajsmeisv/layout-test-results/fast/dom/Window/window-constructor-expected.txt +++ /b/s/w/ioajsmeisv/layout-test-results/fast/dom/Window/window-constructor-actual.txt @@ -0,0 +1,5 @@ +This is a testharness.js-based test. +[FAIL] Test Window and its prototype chain's constructors. + assert_equals: WindowProperties constructor is EventTarget. expected function "function EventTarget() { [native code] }" but got function "function WindowProperties() { [native code] }" +Harness: the test ran to completion. +
Though *why* it's failing, I don't know off hand and will need to dig into it. It does seem worth fixing that. Daniel On Mon, 15 Jul 2024 at 23:29, Leszek Swirski <lesz...@chromium.org> wrote: > I'm not saying that it's subtle and hard to get right, any more so than > any other code we ship at least, I'm saying that it's a full separate code > path and behaviour that we would be shipping to users without running > locally. The difficulties I'm having on android are because of build > config/dependency issues. > > For "how much performance", I'm currently trying to enable it on Android > because it would improve Search page load by what they estimate to be ~24 > SWE-years worth of improvement (Kentaro has a calculation in this doc > <https://docs.google.com/document/d/1QwzaNvSwkXeR2_Du5SnXNKPqA3ZTrh8bBK0kbC5T4BI/edit?tab=t.0>). > Also +Kouhei Ueno <kou...@google.com> who has been looking into the > impact of context setup on page load, and +Camillo Bruni > <cbr...@chromium.org> who looked at the performance with Scott. > > On Tue, 16 Jul 2024, 02:43 Nico Weber, <tha...@chromium.org> wrote: > >> If the code path behind use_v8_context_snapshot is subtle and hard to get >> right, it sounds like there's our second reason for not having it, right >> there :) >> >> How much performance does the blink snapshot buy us? Is it possible to >> get some of that with less expensive techniques? >> >> (+sky who I think looked at this at some point.) >> >> On Monday, July 15, 2024 at 2:54:35 PM UTC-4 Leszek Swirski wrote: >> >>> +Michael Lippautz <mlippa...@google.com> >>> >>> I'm not sure we should do this for build time reasons alone. >>> `use_v8_context_snapshot` is the default behaviour in shipping browsers, >>> and it makes the renderer take quite a different path during page load / >>> navigation. If we disable it in regular builds, then regular builds >>> (including all the dchecks!) won't be running and texting the same code >>> that we're shipping. >>> >>> The fact that tests are failing with this flag change should be a huge >>> flashing red light about this proposal - if we make the tests not test the >>> code we're shipping, then we risk it breaking without us noticing. Indeed, >>> I've been trying to turn this flag on for Android, and have been struggling >>> to do so. >>> >>> - Leszek >>> >>> >>> On Mon, 15 Jul 2024, 20:25 Dave Tapuska, <dtapu...@chromium.org> wrote: >>> >>>> Have you thought about setting gn config v8_use_external_startup_data >>>> on any bots? >>>> >>>> I don't know why they are failing. The window constructor one is weird >>>> as well because the prototype chain is different... >>>> >>>> dave. >>>> >>>> On Mon, Jul 15, 2024 at 2:13 PM Nico Weber <tha...@chromium.org> wrote: >>>> >>>>> Hello, >>>>> >>>>> use_v8_context_snapshot causes us to build lots of files (blink + >>>>> dependencies) twice on bots that cross-compiler (win/arm64, android, etc). >>>>> >>>>> We'd like to turn off use_v8_context_snapshot in regular release >>>>> builds by default, and only keep it enabled in is_official_build builds. >>>>> >>>>> However, a small number of tests, almost all of >>>>> them inspector-protocol tests, fail if I try this: >>>>> https://chromium-review.googlesource.com/c/chromium/src/+/5704136 >>>>> >>>>> That's surprising to me. I would've expected use_v8_context_snapshot >>>>> to not change behavior. >>>>> >>>>> Does anyone have an idea why this might happen? >>>>> >>>>> Thanks, >>>>> Nico >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "blink-dev" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to blink-dev+unsubscr...@chromium.org. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADZ1XibPV%3Dd448fckQeYFaO617_9aahsxysAjMEdQ4sy%3DQw4kQ%40mail.gmail.com >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CADZ1XibPV%3Dd448fckQeYFaO617_9aahsxysAjMEdQ4sy%3DQw4kQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "blink-dev" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to blink-dev+unsubscr...@chromium.org. >>>> >>> To view this discussion on the web visit >>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAHgVhZU-er_dfh_esgBmfLQ%2BOVf24y2yN7K6W6yjGqNkH%3Df%3D6w%40mail.gmail.com >>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAHgVhZU-er_dfh_esgBmfLQ%2BOVf24y2yN7K6W6yjGqNkH%3Df%3D6w%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to blink-dev+unsubscr...@chromium.org. > To view this discussion on the web visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGRskv_WMBbxoTeVLhK4Pst0tSk6gOnC2ijy6vdH86P1y_bAZA%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGRskv_WMBbxoTeVLhK4Pst0tSk6gOnC2ijy6vdH86P1y_bAZA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAF3XrKo_LKE%3D6O4eXmTHjUm_bqg-BR0iExHKcziSOCpTimiaDA%40mail.gmail.com.