RenderStatePackager is not using multiple threads on MacOS

[speedym]

CPU usage of RenderStatePackager is around 10% with 90% of the CPU being idle when compiling multiple .json files on MacOS (--metal_ios).

[MikhailGorobets]

@speedym What is stage of execution? Shader compilation or archive serialization?
Also try experimenting with the number of threads (argument -t)

[speedym]

@MikhailGorobets I have sent a repro case via email as it is under NDA. I think only one instance of the metal tool is called at any given moment.

[speedym]

I have just retested with the latest RenderStatePackager and I can confirm that this issue has not been fixed. The idle% when using top command line tool is 90%, and the average CPU usage is around 10%.

[TheMostDiligent]

The packager starts the specified number of threads, and on MacOS it starts individual process to compile shaders in every thread. Our initial investigation showed that there is a bottleneck in GLSLang memory allocator.
We will investigate this issue further.

[TheMostDiligent]

Apparently, this works OK on M1 MacBooks, so there might be some issue on Apple side.
@speedym closing this now, but feel free to reopen if the issue is still relevant.