You can disable the feature by setting a GN flag to false. https://source.chromium.org/chromium/chromium/src/+/main:tools/v8_context_snapshot/v8_context_snapshot.gni;drc=6b626d7f721fc8805bd9f615e60a25f5b4d892fd;l=18
You can set `use_v8_context_snapshot` to false. Cheers, Yuki Shiino 2021年9月7日(火) 21:09 Rahul Patel <patelrahulkum...@gmail.com>: > Nice feature, i have a quick questions on enabled this feature? > > Just for my learning purpose Can we disabled it for linux too? > > On Tuesday, March 20, 2018 at 7:56:59 AM UTC+5:30 Hitoshi Yoshida wrote: > >> >> 2018年3月20日(火) 3:20 Dirk Pranke <dpr...@chromium.org>: >> >>> Isn't it already enabled for release desktop builds? I thought from >>> up-thread it was only disabled for Android, CrOS, and cross-builds. >>> >> Yes, it's already enabled on desktop platforms. >> We would like to additionally enable it on (a part of) Android builds. >> CrOS and other cross-build platforms are not supported yet, and not the >> target of this update. >> >> >>> If this requires us to compile Blink twice, I think it's probably not >>> worth it to enable for Android release builds, just like we wouldn't enable >>> PGO or LTO by default. >>> >>> -- Dirk >>> >>> On Mon, Mar 19, 2018 at 11:12 AM, Ojan Vafai <oj...@chromium.org> wrote: >>> >>>> Is there an eventual path towards enabling this for release builds and >>>> desktop? A lot of people do local performance testing on release builds, so >>>> it's best if the differences between release and official are as minimal as >>>> possible to avoid performance testing on something too different from what >>>> we see in the wild. >>>> >>>> I believe it does not affect most metrics, but yes, it's better to care >> performance tests. >> Thank you for pointing it out. >> >> >>> >>>> On Mon, Mar 19, 2018 at 12:49 AM Hitoshi Yoshida <pe...@chromium.org> >>>> wrote: >>>> >>> I'm sorry not to reply this thread so long. >>>>> >>>>> As an internal discussion, we decide to enable this feature on >>>>> official build Android Chrome. >>>>> (To move this decision public forward, we also need other agreements. >>>>> And I'll send another Intent-to-Ship for it, with adding some metrics.) >>>>> >>>>> So the current situation about this feature on Android Chromium is >>>>> - Disabled by default. >>>>> - Each developer can enable it with having >>>>> "use_v8_context_snapshot=true" in their arg.gn. (Yes, you already can >>>>> try it locally.) >>>>> - It needs to build Blink twice (once for Android, and the other for >>>>> the host machine), so it takes time to build. >>>>> and we'd like to update as >>>>> - Enable it on official build (is_official_build=true) >>>>> - Still need to put "use_v8_context_snapshot=true" if each developer >>>>> wants to enable it. >>>>> - The change will not affect on general developers environment, i.e. >>>>> in local build and CQ. >>>>> - General bugs of V8ContextSnapshot feature will be caught on other >>>>> platforms' trybots in CQ. >>>>> - Android specific bugs of V8ContextSnapshot feature will be caught in >>>>> an official bot, which is out of CQ. But the case should be rare, and it >>>>> should be reproduced on local machines. >>>>> >>>>> stay tuned for the intent-to-ship. >>>>> >>>> 2018年2月2日(金) 14:48 Kentaro Hara <har...@chromium.org>: >>>>> >>>> Here are a couple of my thoughts: >>>>>> >>>>>> - I don't think it's acceptable to significantly regress build time >>>>>> on non-Google developers. >>>>>> >>>>>> - In the first place, I don't yet understand why we have to build >>>>>> Blink twice in the cross-compiling environment. Given that the context >>>>>> snapshot is used by the target machine, the snapshot should be taken at >>>>>> the >>>>>> target machine -- then why do we need to build Blink on the host machine? >>>>>> >>>>>> - Either way, I think we need to come up with a plan that 1) doesn't >>>>>> significantly affect build time of trybots or non-Google developers and >>>>>> 2) >>>>>> doesn't regress test coverage. Let's discuss the details among experts >>>>>> offline and get back to this thread. >>>>>> >>>>>> >>>>>> >>>>>> On Thu, Feb 1, 2018 at 8:14 PM, Daniel Bratell <bra...@opera.com> >>>>>> wrote: >>>>>> >>>>> From a non-Googlers point of view, I am curious about the effect when >>>>>>> you don't have access to 500 parallel cores to compile on. Not everyone >>>>>>> have access to that kind of hardware. If the added targets end up using >>>>>>> 200 >>>>>>> cores that would otherwise have been idle, I can see why it only took >>>>>>> 10% >>>>>>> more time, but it would look completely different for someone who uses >>>>>>> all >>>>>>> available cores already. >>>>>>> >>>>>>> /Daniel >>>>>>> >>>>>>> On Thu, 01 Feb 2018 05:00:19 +0100, Hitoshi Yoshida < >>>>>>> pe...@chromium.org> wrote: >>>>>>> >>>>>>> I'm sorry. The number 29->46 minutes is not reliable, because >>>>>>> trybots builds incrementally. >>>>>>> I tried to build everything on my machine using goma. >>>>>>> $ ninja -j 500 -C out/Android >>>>>>> Then the compile time changes from 17'30" to 19'16", and hence its >>>>>>> regression is ~10%. >>>>>>> >>>>>>> >>>>>>> 2018-01-30 2:14 GMT+09:00 Daniel Bratell <bra...@opera.com>: >>>>>>> >>>>>>>> On Wed, 24 Jan 2018 07:12:02 +0100, Hitoshi Yoshida < >>>>>>>> pe...@chromium.org> wrote: >>>>>>>> >>>>>>>> Currently v8_context_snapshot.bin is created if >>>>>>>> use_v8_context_snapshot is true. >>>>>>>> It is set true by default depending on the build environment (see >>>>>>>> v8_context_snapshot.gni >>>>>>>> <https://cs.chromium.org/chromium/src/tools/v8_context_snapshot/v8_context_snapshot.gni>) >>>>>>>> but you can set it false in gn args. >>>>>>>> >>>>>>>> IIUC, most trybots do not build blink twice, because they are not >>>>>>>> cross-build bots or setting use_v8_context_snapshot false. >>>>>>>> However, in near future, we want to enable this feature also on >>>>>>>> Android, and it must increase compile time for x1.5. >>>>>>>> (Some my WIP CLs show that compile time will become 46 min. from 29 >>>>>>>> min on android_n5x_swarming_rel >>>>>>>> <https://ci.chromium.org/buildbot/tryserver.chromium.android/android_n5x_swarming_rel/> >>>>>>>> .) >>>>>>>> So it worth discussing what the default value of >>>>>>>> use_v8_context_snapshot should be. >>>>>>>> >>>>>>>> >>>>>>>> 29 -> 46 minutes, that would be with goma? What would be the change >>>>>>>> for a local build? >>>>>>>> >>>>>>>> I'm not sure exactly where this will apply but 50% higher >>>>>>>> compilation times in general would be painful when it can already take >>>>>>>> hours. >>>>>>>> >>>>>>>> /Daniel >>>>>>>> >>>>>>>> -- >>>>>>>> /* Opera Software, Linköping, Sweden: CET (UTC+1) */ >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> Hitoshi Yoshida (Peria) >>>>>>> email: pe...@chromium.org >>>>>>> -- >>>>>>> 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+...@chromium.org. >>>>>>> >>>>>>> To view this discussion on the web visit >>>>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJnxdXA5%2BNuNUWs677pOAVWfWbsbFjSJx-G5yG64WAFjJ1g5yw%40mail.gmail.com >>>>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJnxdXA5%2BNuNUWs677pOAVWfWbsbFjSJx-G5yG64WAFjJ1g5yw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>>>> . >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> -- >>>>>>> /* Opera Software, Linköping, Sweden: CET (UTC+1) */ >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Kentaro Hara, Tokyo, Japan >>>>>> >>>>> >>>>> >>>>> -- >>>>> Hitoshi Yoshida (Peria) >>>>> email: pe...@chromium.org >>>>> >>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "blink-dev" group. >>>>> >>>> To view this discussion on the web visit >>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJnxdXCbJTJDMEB7OaWv3XhQi%2BJ_E9i%3D0-AV0nEwBt18jVAYyw%40mail.gmail.com >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAJnxdXCbJTJDMEB7OaWv3XhQi%2BJ_E9i%3D0-AV0nEwBt18jVAYyw%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> >> -- >> Hitoshi Yoshida (Peria) >> email: pe...@chromium.org >> > -- 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/CAN0uC_T5V%2Bze1_x6U30_xWr5CM_FSBL5wbzJEk0_aougdgyRHg%40mail.gmail.com.
