[onert] Investigate runtime config

[hseok-oh]

Let's check current implementation for runtime config and find better way.

How to set runtime config?

• Using nnfw API
  • nnfw_set_available_backends: set backend
  • nnfw_set_config: Internal API for debugging (define in nnfw_internal.h)
• NNPackage's config file: metadata's config field
• Setting environment variable

When runtime get config value?

• Before model loading
  • Get from nnfw API: nnfw_set_config and nnfw_set_config
  • Read from NNPackage's config file (on model loading API)
• Get value any time
  • Read environment variable

How to pass config to each runtime module?

• Config util function set config string map to global variable
• Each module read config from global variable

Why we are using environment variable?

• For test environment
  • To maintain NNAPI test
  • To maintain easy general test
  • For easy debugging

Why we are using global variable?

• Read configuration on backend
  • We don't have backend API to pass config value for backend
  • ex. ACL_LAYOUT, EXECUTOR
• Configuration for compiler and executor
  • We don't have struct and interface for them

Environment variable is optional

• When we start runtime project, we support environment variable only
• Now environment variable is for testing and debugging
  • Runtime user may apps, and they will use nnfw API
• Security issue - tizen release runtime is not using environment variable

[hseok-oh]

Can we remove environment variable config on runtime?

• On most test, possible
  • Move config reading from environment variable to test binary from runtime
  • After reading environment variable, use internal API
• Issue: NNAPI test - cannot use nnfw API

Can we remove NNAPI test?

• Coverage issue - many operation are tested by NNAPI test

Move environment variable reading to frontend

• Use same phase for all config method
  • Before model loading (graph construction)
  • For NNAPI
    • Read environment variable on model create?
    • Howto set config value
      • Set global variable on NNAPI frontend?
      • Pass config struct to compilation struct and compile?

[hseok-oh]

Used on CI Test

• General test
  • DISABLE_COMPILE
  • BACKEND
  • EXECUTOR
• Mixed test
  • OP_BACKEND_XXXX (Operator-Backend mapping)
  • ACL_LAYOUT
  • RUY_THREADS

Using modules

• Frontend
  • USE_MMAPED_DATA
• Core
  • GRAPH_DOT_DUMP
  • BACKENDS
  • OP_BACKEND_ALLOPS
  • OP_BACKEND_MAP
  • DISABLE_COMPILE
  • ONERT_LOG_ENABLE
  • CPU_MEMORY_PLANNER
  • EXECUTOR
  • PROFILING_MODE
  • USE_SCHEDULER
  • TRACE_FILEPATH
  • FP16_ENABLE
  • RUY_THREADS (builtin backend)
• Backend
  • EXECUTOR
  • ACL_LAYOUT
  • RUY_THREADS
  • XNNPACK_THREADS

Appendix

• EXECUTOR is used both core and backend
• NCNN_LAYOUT is not used any more