If we do so we could also only do so in build configurations that are actually cross-compiling -- the build time overhead on, e.g., Linux x64 targeting Linux x64 is much less.
On Tue, Jul 16, 2024 at 11:28 AM Leszek Swirski <lesz...@chromium.org> wrote: > We could also disable for, e.g., developer debug builds, but keep enabled > on bots (there's some precedent in V8 for "fast snapshots" for local dev > builds). > > On Tue, Jul 16, 2024 at 5:26 PM Scott Violet <s...@chromium.org> wrote: > >> The v8 snapshots provide substantial performance gains. Leszek provided >> the data to back that up. We shouldn't remove them. The v8 team is in the >> best position to answer if there are other strategies that could give the >> same performance wins without having the additional build time. >> >> While I believe we shouldn't remove the snapshots, I sympathize with the >> desire for faster builds. Seems like the thing we care about is ensuring we >> don't regress test coverage. So, if we were to disable the snapshots on >> many bots, we need to ensure we have at least one bot (on the main >> waterfall) that is building the snapshots. >> >> -Scott >> >> On Mon, Jul 15, 2024 at 5:43 PM 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-Nso4p3X-%3DEBPpi08h246gbjTRP8v7rVx%2BS3dH925%3D6A%40mail.gmail.com > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAGRskv-Nso4p3X-%3DEBPpi08h246gbjTRP8v7rVx%2BS3dH925%3D6A%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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