Squashed 'build/dobuild/' changes from b017db7..f2f5f7f

f2f5f7f sets container parallel flags to intern parallel
59e8140 limit cpus to max of available

git-subtree-dir: build/dobuild
git-subtree-split: f2f5f7f26bb5112115f66a4fed5db5a83087b661

docker.mk

@@ -344,11 +344,10 @@ ifeq ($(docker_portable_workspace),)
   container_destdir = $(abspath $(DESTDIR))
 endif
 
-container_cpus = $(INTERNPARALLEL)
+container_cpus = $(call min,$(INTERNPARALLEL) $(JOBSLOTS_DEFAULT))
 container_cpuperiod = 100000
 container_quota = $(call bc,($(container_cpus)*$(container_cpuperiod)))
-# allow twice as much parallel executions, while container are already limited by cgroup
-container_nproc = $(call bc,(2*$(container_cpus)))
+container_nproc = $(INTERNPARALLEL)
 
 docker_runflags += $(DOCKER_RUNFLAGS)
 docker_runflags += $(addprefix --cpus ,$(container_cpus))