more detailed docs for py and c

Author: jackalcooper

mlir/include/mlir-c/ExecutionEngine.h

@@ -46,7 +46,11 @@ MLIR_CAPI_EXPORTED MlirExecutionEngine mlirExecutionEngineCreate(
     MlirModule op, int optLevel, int numPaths,
     const MlirStringRef *sharedLibPaths, bool enableObjectDump);
 
-/// Execute the global constructors from the module.
+/// Initialize the ExecutionEngine. Global constructors specified by
+/// `llvm.mlir.global_ctors` will be run. One common scenario is that kernel
+/// binary compiled from `gpu.module` gets loaded during initialization. Make
+/// sure all symbols are resolvable before initialization by calling
+/// `mlirExecutionEngineRegisterSymbol` or including shared libraries.
 MLIR_CAPI_EXPORTED void mlirExecutionEngineInitialize(MlirExecutionEngine jit);
 
 /// Destroy an ExecutionEngine instance.

mlir/lib/Bindings/Python/ExecutionEngineModule.cpp

@@ -129,7 +129,12 @@ NB_MODULE(_mlirExecutionEngine, m) {
           [](PyExecutionEngine &executionEngine) {
             mlirExecutionEngineInitialize(executionEngine.get());
           },
-          "Initialize the ExecutionEngine.")
+          "Initialize the ExecutionEngine. Global constructors specified by "
+          "`llvm.mlir.global_ctors` will be run. One common scenario is that "
+          "kernel binary compiled from `gpu.module` gets loaded during "
+          "initialization. Make sure all symbols are resolvable before "
+          "initialization by calling `raw_register_runtime` or including "
+          "shared libraries.")
       .def(
           "dump_to_object_file",
           [](PyExecutionEngine &executionEngine, const std::string &fileName) {