[Bf-blender-cvs] [df29211eeb5] master: Cycles: Speed up oneAPI GPU binaries compilation by using parallel instances

[Nikita Sirgienko]

Commit: df29211eeb59f54079123e2bc82578a561431290
Author: Nikita Sirgienko
Date:   Tue Oct 4 18:19:37 2022 +0200
Branches: master
https://developer.blender.org/rBdf29211eeb59f54079123e2bc82578a561431290

Cycles: Speed up oneAPI GPU binaries compilation by using parallel instances

This change speeds up the compilation at the cost of higher memory usage.
CMake implementation checks the amount of available memory to spawn a
reasonable number of parallel compiler jobs.

===================================================================

M	intern/cycles/kernel/CMakeLists.txt

===================================================================

diff --git a/intern/cycles/kernel/CMakeLists.txt b/intern/cycles/kernel/CMakeLists.txt
index 565e50b3108..682baf7c050 100644
--- a/intern/cycles/kernel/CMakeLists.txt
+++ b/intern/cycles/kernel/CMakeLists.txt
@@ -727,6 +727,17 @@ if(WITH_CYCLES_DEVICE_ONEAPI)
     ${SRC_UTIL_HEADERS}
   )
 
+  set (ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS 1)
+  if (WITH_CYCLES_ONEAPI_BINARIES)
+    cmake_host_system_information(RESULT AVAILABLE_MEMORY_AMOUNT QUERY AVAILABLE_PHYSICAL_MEMORY)
+    # Conservative value of peak consumption here, just to be fully sure that other backend compilers will have enough memory as well
+    set(ONEAPI_GPU_COMPILER_MEMORY_AT_PEAK_MB 8150)
+    math(EXPR ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS "${AVAILABLE_MEMORY_AMOUNT} / ${ONEAPI_GPU_COMPILER_MEMORY_AT_PEAK_MB}")
+    if (ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS LESS 1)
+      set(ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS 1)
+    endif()
+    message(STATUS "${ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS} instance(s) of oneAPI offline compiler will be used.")
+  endif()
   # SYCL_CPP_FLAGS is a variable that the user can set to pass extra compiler options
   set(sycl_compiler_flags
       ${CMAKE_CURRENT_SOURCE_DIR}/${SRC_KERNEL_DEVICE_ONEAPI}
@@ -735,6 +746,8 @@ if(WITH_CYCLES_DEVICE_ONEAPI)
       -fdelayed-template-parsing
       -mllvm -inlinedefault-threshold=300
       -mllvm -inlinehint-threshold=400
+      -fsycl-device-code-split=per_kernel
+      -fsycl-max-parallel-link-jobs=${ONEAPI_OFFLINE_COMPILER_PARALLEL_JOBS}
       -shared
       -DWITH_ONEAPI
       -ffast-math