Bug / Crash 1fps, error with burst

[MonsterJoe]

Hi,

having some trouble with low fps and burst compilation.

I am running on 2021.3.1f1, Burst 1.7.2 and keep getting 4 of these warnings:

> Compilation was requested for method `Unity.Jobs.IJobExtensions+JobStruct`1[[Obi.ConstraintSorter+CountSortPerFirstParticleJob`1[[Obi.BurstContact, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]], Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]], UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null::Execute(Obi.ConstraintSorter+CountSortPerFirstParticleJob`1[[Obi.BurstContact, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]]&, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null|System.IntPtr, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089|System.IntPtr, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089|Unity.Jobs.LowLevel.Unsafe.JobRanges&, UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null|System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)` but it is not a known Burst entry point. This may be because the [BurstCompile] method is defined in a generic class, and the generic class is not instantiated with concrete types anywhere in your code.

And the simulations then run at about 1fps (i7, 64 gb ram, RTX 3060)

Anything I do here?

Edit: Tried the raclette example with Oni back end, it's equally slow

[josemendez]

Hi,

having some trouble with low fps and burst compilation.

I am running on 2021.3.1f1, Burst 1.7.2 and keep getting 4 of these warnings:

> Compilation was requested for method `Unity.Jobs.IJobExtensions+JobStruct`1[[Obi.ConstraintSorter+CountSortPerFirstParticleJob`1[[Obi.BurstContact, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]], Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]], UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null::Execute(Obi.ConstraintSorter+CountSortPerFirstParticleJob`1[[Obi.BurstContact, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null]]&, Obi, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null|System.IntPtr, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089|System.IntPtr, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089|Unity.Jobs.LowLevel.Unsafe.JobRanges&, UnityEngine.CoreModule, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null|System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089)` but it is not a known Burst entry point. This may be because the [BurstCompile] method is defined in a generic class, and the generic class is not instantiated with concrete types anywhere in your code.

And the simulations then run at about 1fps (i7, 64 gb ram, RTX 3060)

Anything I do here?

Edit: Tried the raclette example with Oni back end, it's equally slow

Hi there,

Been able to reproduce this in Burst 1.7, not reproducible with previous versions though. This looks like a bug in Burst, since the CountSortPerFirstParticleJob in Obi.ConstraintSorter is not defined in a generic class. It is defined in a generic method though, and the method is called with a concrete type in BurstSolverImpl.cs line 676.

This error would mean the code is not being compiled by Burst, and will result in very slow simulation.

Will report this to Unity and get back to you.

Note: despite the warning above mentioned, make sure you've disabled the jobs debugger as stated in the manual, as that will cause the simulation to run even slower: http://obi.virtualmethodstudio.com/manua...kends.html

[josemendez]

Seems like the above warning does not stop Burst from compiling all other jobs, so this result only in a very slight performance drop. Most simulations should run at normal speed, so 1 fps is abnormal behavior.

Make sure you've disabled the jobs debugger and safety checks as I suggested above. If it's still slow, would it be possible for you to share a picture of your profiler in timeline mode so that I can take a look ?

kind regards,

[MonsterJoe]

Seems like the above warning does not stop Burst from compiling all other jobs, so this result only in a very slight performance drop. Most simulations should run at normal speed, so 1 fps is abnormal behavior.

Make sure you've disabled the jobs debugger and safety checks as I suggested above. If it's still slow, would it be possible for you to share a picture of your profiler in timeline mode so that I can take a look ?

kind regards,

Thanks for the quick response! Yes, will have a look and report back later in the day.

[MonsterJoe]

Thanks for the quick response! Yes, will have a look and report back later in the day.

Ok, tried it out and it's working now. I think going back burst 1.6 has the largest impact. Also saw that it was the recommended version. Again thanks!