[browser] improve default initial memory size

[pavelsavara]

In both normal and re-link with wasm workload

Make default initial memory size:

• size of loaded DLLs x1.2
• plus size of AOT DATA segments
• rounded to 64KB page
• 16MB if they are smaller

Contributes to #61925
Contributes to #66313
Contributes to #79909
Contributes to #73949

Simplified backport to Net7 is #80849

[ghost]

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Issue Details

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In both normal and re-link with wasm workload

Contributes to #61925

Author:	pavelsavara
Assignees:	pavelsavara
Labels:	arch-wasm, area-System.Runtime.InteropServices.JavaScript
Milestone:	8.0.0

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[pavelsavara]

AOT
wasm-ld : error : initial memory too small, 20984208 bytes needed
wasm-ld : error : initial memory too small, 22961344 bytes needed

Microsoft.Extensions.Configuration.Functional.Tests Log

System.Runtime.Tests Log

I guess we need calculated value ? But what would be good way how to obtain it ?

[pavelsavara]

But what would be good way how to obtain it ?

Here the wasm-ld would calculate minimal value it needs for stack and global variables, and segment sizes
https://github.com/llvm/llvm-project/blob/540e58af6692bf373d9be4f99d320b4b0f753e3b/lld/wasm/Writer.cpp#L352-L363

But unfortunately emscripten is sending a specific value
https://github.com/emscripten-core/emscripten/blob/8fc4ea5d3e62642664a9bb95c4413bba3d349f71/src/settings.js#L161

Why our AOT adds data segments ?

[pavelsavara]

I suspect that the extra data in the data segment when AOT are coming from mapping metadata_token -> wasm func index.
It's 0.8MB difference in data segment size for src\mono\sample\wasm\browser-advanced sample (hello world).

@vargaz

• is such size increase of data segment reasonable ?
• how do I validate that the extra data are indeed the function mapping and not something else ?
• could we store wasm func index in the IL metadata instead of the token ?
• what would be good algo to estimate the extra size from AOT in order to bump initial memory size during the build time ?

[lewing]

#80653 is related

[radekdoulik]

One possible improvement, which doesn't need to be part of this PR, is to not run the llvm-size and the task when the memory size is already set by the user.

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[lewing]

I like the idea of eventually using the managed path in the task but that is an implementation detail that can be prioritized separately

[radical]

Looking good. Some comments.

[pavelsavara]

/azp run runtime-wasm

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[radical]

LGTM! 👍

[pavelsavara]

CI failures are unrelated

[ChristianA1992]

I tried the .net 7 backport.
I didn't really do much for loading the app. Atleast not on chromium browser which are very slow compared to firefox.
Maybe I'm stilling missing more, for my app to load faster.

[maraf]

I tried the .net 7 backport.
I didn't really do much for loading the app. Atleast not on chromium browser which are very slow compared to firefox.
Maybe I'm stilling missing more, for my app to load faster.

This change doesn't actually speed up loading the app. It changes the amount of memory that is allocated when the app starts.