@ivokub need your help and review!

@ivokub need your help and review!

On it. Would it be possible to allow adding commits directly to the branch for easier review?

@ivokub need your help and review!

On it. Would it be possible to allow adding commits directly to the branch for easier review?

Sure, I've add grant you push permission in https://github.com/okx/gnark/invitations

Let me delete those examples to keep the PR clean

I'm not able to create a proof for now, in the debug logs I see the last action is:

�[90m14:05:05�[0m DBG Bs.MultiExp done �[36mMSMG2 5 took=�[0m0.86421 �[36macceleration=�[0mzeknox �[36mbackend=�[0mgroth16 �[36mcurve=�[0mbn254 �[36mnbConstraints=�[0m6

I guess it is probably some deadlock somewhere. Have you been able to run end-to-end prover?

Hi Ivo,

May I check: if you use the precompiled zeknox libraries, does your GPU have compute capability 8.6 or 8.9? (only these two are supported by our precompiled libraries).

On our systems, the end-to-end example (go run -tags=zeknox examples/zeknox/main.go) is working.

Hi Ivo,

May I check: if you use the precompiled zeknox libraries, does your GPU have compute capability 8.6 or 8.9? (only these two are supported by our precompiled libraries).

On our systems, the end-to-end example (go run -tags=zeknox examples/zeknox/main.go) is working.

I'm using AWS g4dn.xlarge instance which by documentation is T4. And it seems it is compute capability 7.5.

Should it work if I compile the libraries myself? I started compiling them, but it took quite a bit of time and I didn't let it terminate. When I benchmarked previously, then g4dn was quite good balance between performance and $-per-proof cost.

Yeah, compile by yourself should work. Compile BN254 MSM G2 takes ~5mins on our device. expect a long compile time

Use this script
https://github.com/okx/zeknox/blob/main/native/build-release-msm-bn254.sh

Use this script https://github.com/okx/zeknox/blob/main/native/build-release-msm-bn254.sh

Indeed I got it working and the speedup is similar to the one claimed in the PR (1.6x). I also had to build libblst.

But now it seems that there is an issue with the proof, I get invalid proof:

panic: points in the proof are not in the correct subgroup

I could try looking into it, but it would probably take a bit time to compare the computed values against CPU execution - would it be possible to try out with another GPU and see if you hit the same problem?

This is an edge case. We found this bug, tried many methods to fix it, but it still happens...
I will look into it.

Hi @ivokub, my latest commit fixes (temporarily) the issue with invalid proof. We observe that this issue appears in multi-GPU environments with relatively low frequency but we did not find the reason. If the proof is invalid, we recompute only the invalid points on CPU. We still observe 25-50% speedup even when this issue appears. Please review. Thank you.

Hi @ivokub, my latest commit fixes (temporarily) the issue with invalid proof. We observe that this issue appears in multi-GPU environments with relatively low frequency but we did not find the reason. If the proof is invalid, we recompute only the invalid points on CPU. We still observe 25-50% speedup even when this issue appears. Please review. Thank you.

Thanks for the update. It takes a bit time to review more. We actually intend to make different proving backend support more modular, so I would like to get that done before.