Support 16 KB page sizes

[ntoan69]

Is your feature request related to a problem? Please describe.

16 KB Google Play compatibility requirement
Starting November 1st, 2025, all new apps and updates to existing apps submitted to Google Play and targeting Android 15+ devices must support 16 KB page sizes on 64-bit devices.

Describe the solution you'd like

Compile 16 KB-aligned shared libraries

Describe alternatives you've considered

Additional context

[ericstj]

Can you be more specific about which module needs to change and how? I wouldn't expect this to apply to managed code, and I don't think any of the native libraries provided by this repo would apply when running in Android.

[ntoan69]

Publishing an MAUI app that uses Microsoft.ML, the following warnings occur:

Android 16 will require 16 KB page sizes, shared library 'libLdaNative.so' does not have a 16 KB page size. Please inform the authors of the NuGet package 'Microsoft.ML' version '4.0.2' which contains 'runtimes/linux-arm64/native/libLdaNative.so'. See https://developer.android.com/guide/practices/page-sizes for more details.
Android 16 will require 16 KB page sizes, shared library 'libLdaNative.so' does not have a 16 KB page size. Please inform the authors of the NuGet package 'Microsoft.ML' version '4.0.2' which contains 'runtimes/linux-x64/native/libLdaNative.so'. See https://developer.android.com/guide/practices/page-sizes for more details.

[MartBentNedap]

I can confirm this happens for our Maui app as well. Part of the cause is LightGBM not compiling their libraries for 16 KB page sizes.

I have created a issue in their repo to address this, but I doubt they will pick this up any time soon since (I assume) its only a small use case, and a pretty big change, on their end.

The issue: microsoft/LightGBM#7065

[ericstj]

Sounds like we need to update our cmake scripts with some setting to enable this. Let's see if copliot can figure it out.

[ericstj]

See my comments in https://github.com/dotnet/machinelearning/pull/7539/files#r2475932351

I'm not sure we want to change this.

Are you actually using LightLDA / LatentDirichletAllocationTransformer? If not then just exclude those binaries from your application.

[MartBentNedap]

See my comments in https://github.com/dotnet/machinelearning/pull/7539/files#r2475932351

I'm not sure we want to change this.

Are you actually using LightLDA / LatentDirichletAllocationTransformer? If not then just exclude those binaries from your application.

Yes this was my thought as well, the LightGBM library had the same problem. Its a big change with unknown consequences for a small use case of this library.

We use the PredictionEngine in our mobile application. I just checked and I think we are using the wrong package. We use Microsoft.ML.LightGBM, but I think we can get away with just using Microsoft.ML which does not require the LightGBM library. Though, the 'libLdaNative.so' would still have to be built 16 KB page sizes.

For now we have decided to exclude any libraries that do now comply with the new page size requirement. This does feel like a hassle for the Maui ecosystem though. Since its strength was its ability to "just use" existing .NET libraries.