Support building Kaldi to WASM with OpenBLAS

[msqr1]

Kaldi with OpenBLAS 0.3.28 with some mini hacks and performance increased by 20% (#4952)

[msqr1]

@jtrmal PTAL at the changes as well as the guide itself here: https://github.com/msqr1/kaldi-wasm2. I also have to force the number threads spawned by Kaldi to be 1 because WASM is quite complicated with multiple threads (we can support that later). I know g_num_threads control this, but is there any other place where kaldi spawn threads?

Thanks!

[jtrmal]

Hi, thank you, will try to get to this this week y.

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On Wed, Oct 16, 2024 at 7:39 AM __Rylex__ ***@***.***> wrote: @jtrmal <https://github.com/jtrmal> PTAL at the changes as well as the guide itself here: https://github.com/msqr1/kaldi-wasm2. Thanks! — Reply to this email directly, view it on GitHub <#4954 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACUKYX2XXMXCPSAVDJKVCNTZ3X3XTAVCNFSM6AAAAABP7NIIG2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDIMJVG43TSMJUHA> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[msqr1]

Could you answer my question so I can work on it?

[jtrmal]

I'm sorry I don't see any question. Y.

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On Wed, Oct 16, 2024 at 19:07 __Rylex__ ***@***.***> wrote: Could you answer my question so I can work on it? — Reply to this email directly, view it on GitHub <#4954 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACUKYXY3SMLR6LAJP3ZQYF3Z32MM3AVCNFSM6AAAAABP7NIIG2VHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDIMJXGQZDKMBZGE> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[msqr1]

Is there any other place where kaldi spawn threads other than the controlled g_num_threads in kaldi_thread.cc?

[danpovey]

I think just from libraries e.g. some math libraries, like MKL, spawn their own threads. (This is usually not helpful and should be disabled by appopriate environment variables or liberary versions)

[msqr1]

OK, so I can force kaldi to spawn 1 thread by setting g_num_threads to 1. I will have to force all creations of std::thread to be 1 when building to WASM (except the CUDA ones), right?

Btw, what is the difference between g_num_threads =1 vs =0? @danpovey

[danpovey]

The vast majority of Kaldi programs only use one thread anyway so you probably don't have to do anything in most cases.

[csukuangfj]

By the way, sherpa-onnx also uses a single thread in its WebAssembly ASR and TTS APPs. And the speed also looks OK, e.g., it is able to do real-time speech recongition.

[msqr1]

Thanks! I will TAL at that later. For now, I'm just fixing the threading issue to get this donr!

[danpovey]

I wouldn't attempt to complie the entirety of Kaldi to WASM because the binary size would be enormous. There are
lots of templates and many libraries. I'd compile a single binary at a time. IDK much about how WASM works though
and how the linking etc. is done.