Browser hacking: Improving JS allocation performance by recycling GC heap blocks

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SerenityOS is a Unix-like operating system that I'm implementing from scratch. serenityos.org

[@agentjeb4103]

There's something very satisfying watching the milliseconds of a benchmark drop down as you code.

[@Hendiadyoin1]

the best way to optimize memset would be to let the compiler do it, the compiler can do memset unrolls, to just a few mov's when the size is constant, which we sadly cannot do, with the current way contexpr's work, we would need a way to generate code based upon constant arguments, to make it similar to the performance of the compilers implementation tricks

[@kneekoo]

// Timestamps for a busy friend. :) 0:38 Time taken initially by the test-js suite: ~840ms on a hot run (in SerenityOS) 1:52 What takes time in LibJS: heap blocks 2:34 The plan 19:44 Time taken after the first changes: ~780ms (hot run) 22:17 Time taken after more changes: ~540ms (hot run) 24:51 Halving the cache size from 2MB to 1MB averages the time to ~550ms (hot run) 30:05 With Linux, the time taken to complete a test-js hot run is ~540ms

[@lawrencemanning]

Hey Andreas. Awsome content as usual! Hope you get to do this fulltime soon. And an amusing observation: while looking at code with KiB in it you uttered kilobyte. Couldn't help but chuckle. Its a kilobyte damnit! :)

[@akj7]

4:00 Hm i think one way to solve this would be (I am on mobile and won't have access to a PC in the near future to validate this) to go into File>Setting> (That place where CMake is setup, i think is Toolchains or Build Tools) > Add cmake compiler definition: __serenity__ . Reload CMake.

[@TimMorgan]

Great content as always, and very timely for my own project. Thanks for taking the time to explain your thoughts!

[@Sjefke3000]

28:15: About failing early vs limping along: That depends on the use case, maybe. When developing, fail early is definitely the way to notice and then fix bugs. When running on a mars rover or chemical plant, limping along for a bit might be worth it.

[@LKokos]

Very satifsfying to see that much time save :^)

[@MatheusCostaStutzel]

Hey Andreas, amazing content as usual. There's one thing that catch my attention, not a big deal, but the block name is used only for a new block. From a api point of view it's seems a little odd to ask for a block with name X and receive a block with name Y. Probably not worth the effort to go back and change this. But I would like to ask you, is there a easy way to "fix" it?

[@imalaia8033]

Very entertaining video! How can you find those awesome wall papers? :^)

[@awesomekling]

I found this one on 4chan /wg/, in a "post-apocalyptic" thread: boards.4chan.org/wg/thread/7777386

[@ZackMitkin]

Good video! Can you do more porting videos too?

[@billgatest7563]

you always bring it ty

[@kidkool27]

I just noticed your Viking beard haha!

[@FreeScience]

About doing interactive/performance demanding tasks while running heavy background tasks. Have you looked at Ananicy? Originally a python script, but someone have recently rewritten it in c++. It's a profile based demon that applies priority and niceness values to processes.

[@po1sonseede9001]

He’s slowly making his transformation into a world of warcraft character.

[@dr.deathvolt3058]

I have question , why # include is working in main function ?

[@awesomekling]

I don't understand the question

[@dr.deathvolt3058]

@@awesomekling when I define stdio.h in main funtion, that worked why?

[@lawrencemanning]

@@dr.deathvolt3058 probably because studio.h just contains definitions not declarations. You shouldn't do that in any case.

[@skillerraptor8669]

Hey, I wanted to ask what CLion Theme you are using

[@KeithRollin]

Andreas, if you're worried about spending 1MB on caching these blocks, you could probably recover some of that by first compressing the blocks. And if you zero-fill them first, I bet they'll compress really well!

[@FrostBoost]

haha, "m.. block.. a-llo-ca-tooor"

[@mrkotyuk]

will the interpreter be faster if it is rewritten to pure C ?

[@fabse64]

No.

[@huw008]

A bytecode interpreter would make things faster and allow for more optimisations but hey, one thing at a time. Kling used to work on WebKit, wo he knows his stuff ;)

[@yeppiidev]

@@huw008 oh wow so he wrote half of the code that's used on safari and chrome (chrome web engine is based on WebKit right?)

[@wiktorwektor123]

@@bjarnestronstrup9122 This is why in game developement more developers are changing to ECS (Entity Component System), where you separate data from code operating on it and you organize the same type of data in conignous memory blocks to avoid as much as possible cache miss hits. Even Unity is swiching to this.

[@eccentricsan6019]

is serenity is based on Linux

[@ashtree129]

No, it’s its own os

[@mewhenthemewhenstheme]

No, Serenity has its own kernel.

[@zeroows]

I love your videos but man do I hate C++

[@nnaaaaaa]

>60fps bueno

[@flightvision]

You're also using python as a calculator :)

[@sdwvit]

Hey Andreas, thank you for sharing your work. Have you thought about doing twitch streams live coding? May bring you extra earnings.