make.sh: Calculate MAKETUNING depending on available memory

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

make.sh

@@ -62,16 +62,17 @@ export BASEDIR LOGFILE
 DIR_CHK=$BASEDIR/cache/check
 mkdir $BASEDIR/log/ 2>/dev/null
 
+# Load configuration file
+if [ -f .config ]; then
+	. .config
+fi
+
 # Include funtions
 . tools/make-functions
 
 # Get the amount of memory in this build system
 HOST_MEM=$(system_memory)
 
-if [ -f .config ]; then
-	. .config
-fi
-
 if [ -n "${BUILD_ARCH}" ]; then
 	configure_build "${BUILD_ARCH}"
 elif [ -n "${TARGET_ARCH}" ]; then
@@ -176,11 +177,6 @@ prepareenv() {
     # Setup environment
     set +h
     LC_ALL=POSIX
-    if [ -z $MAKETUNING ]; then
-	CPU_COUNT="$(system_processors)"
-
-	MAKETUNING="-j$(( ${CPU_COUNT} * 2 + 1 ))"
-    fi
     export LFS LC_ALL CFLAGS CXXFLAGS MAKETUNING
     unset CC CXX CPP LD_LIBRARY_PATH LD_PRELOAD
 

tools/make-functions

@@ -150,6 +150,26 @@ configure_build() {
 	fi
 
 	CXXFLAGS="${CFLAGS}"
+
+	# Determine parallelism
+	if [ -z "${MAKETUNING}" ]; then
+		# We assume that each process consumes about
+		# 192MB of memory. Therefore we find out how
+		# many processes fit into memory.
+		local mem_max=$(( ${HOST_MEM} / 192 ))
+
+		local processors="$(system_processors)"
+		local cpu_max=$(( ${processors} * 2 ))
+
+		local parallelism
+		if [ ${mem_max} -lt ${cpu_max} ]; then
+			parallelism=${mem_max}
+		else
+			parallelism=${cpu_max}
+		fi
+
+		MAKETUNING="-j${parallelism}"
+	fi
 }
 
 configure_build_guess() {