reduce the #proc used in make.

R-package/src/install.libs.R

@@ -35,14 +35,14 @@ if (!use_precompile) {
   
   # Prepare installation steps
   cmake_cmd <- "cmake"
-  build_cmd <- "make -j"
+  build_cmd <- "make -j4"
   lib_folder <- file.path(R_PACKAGE_SOURCE, "src", fsep = "/")
   
   # Check if Windows installation (for gcc vs Visual Studio)
   if (WINDOWS) {
     if (use_mingw) {
       cmake_cmd <- paste0(cmake_cmd, " -G \"MinGW Makefiles\" ")
-      build_cmd <- "mingw32-make.exe -j"
+      build_cmd <- "mingw32-make.exe -j4"
     } else {
       cmake_cmd <- paste0(cmake_cmd, " -DCMAKE_GENERATOR_PLATFORM=x64 ")
       build_cmd <- "cmake --build . --target _lightgbm  --config Release"