Build amalgamation using a docker

[OferRosenberg]

Is there a way to build amalgamation using the android docker-multiarch ?
Alternatively, is there a parameter or configuration that can be passed to the docker-multiarch to create an android library which is similar to the one created by amalgamation (predict only, smaller, etc.)

Thanks,
Ofer.

[larroy]

Hi @OferRosenberg Right now we are cross-compiling the full MXNet. So the answer is no. We are also considering removing amalgamation.
related: #8707

[larroy]

Why do you say "predict only"?

[edmBernard]

amalgamation don't have training API, so it only able to do prediction.

[OferRosenberg]

And to my understanding, as it doesn't have the training parts, it should be smaller than the full fledge MxNet. I think there's justification for keeping a predict-only, size optimized, build (either by amalgamation or other)

[b0noI]

proposed labels: "Question"

[wykvictor]

@larroy What's the progress on 'cross-compiling the full MXNet'? For now, what's the best approach to deploy MXnet on Android? Thanks!

[larroy]

Hi, you can use the new scripts in the ci folder: ci/build.py right now it should build for android but the build is untested.

[wykvictor]

@larroy Thanks for the advice! I build android_arm64 successfully using ci/build.py(based on commit 5a480f0 in master) .
But several changes need to be made in the process of cross compilation.
The main issue is that I need to turn off pthread/lapack in CMakeLists.txt.
Suggest to add a variable like 'Android' in it to turn off these flags automatically.

[larroy]

@wykvictor thanks for the feedback, we will likely improve this in the short future. I also think we need some kind of platform detection in CMake. I started doing that but haven't been able to finish it so far.

[ThomasDelteil]

@OferRosenberg please consider closing if your question has been answered. Summary of the conversation:

• There is no amalgation build for Android
• Full MXNet cross-compilation is possible, check out the build scripts/docker images in in ci/build.py
• CMake needs to be improved, this is a WIP, addressed in [MXNET-679] Refactor handling BLAS libraries with cmake #11148

[piyushghai]

@sandeep-krishnamurthy Requesting this issue to be closed.
@OferRosenberg Please feel free to re-open if closed in error. :)