Merge branch 'make-ninja-respect-load' into 'master'

[Makefile] Make ninja consider the load average

See merge request !149

Makefile

@@ -15,8 +15,12 @@ all: build
 export BUILDTYPE ?= debugoptimized
 export BUILDDIR = build-$(BUILDTYPE)
 
+NPROC := $(shell nproc)
+JOBS := $(shell echo $$(( $(NPROC) + 6)))
+LOAD := $(shell echo $$(( $(NPROC) * 2)))
+
 NINJA_BIN ?= ninja
-NINJA := $(NINJA_BIN) $(EXTRA_NINJA_ARGS)
+NINJA := $(NINJA_BIN) -j $(JOBS) -l $(LOAD) $(EXTRA_NINJA_ARGS)
 
 build:
 	[[ -L build ]] || ./tools/prepare-build-dir