Use nproc instead of /proc/cpuinfo to find number of processors for c…

…oncurrency (#5035)

* increase timeout factor to 16

* increase timeout to 40

* custom concurrency

* restore earlier changes, use nproc to find number of processors

* restore JTREG_CONC

openjdk/openjdk.mk

@@ -19,7 +19,7 @@ OS:=$(shell uname -s)
 ARCH:=$(shell uname -m)
 
 ifeq ($(OS),Linux)
-	NPROCS:=$(shell grep -c ^processor /proc/cpuinfo)
+	NPROCS:=$(shell nproc)
 	MEMORY_SIZE:=$(shell KMEMMB=`awk '/^MemTotal:/{print int($$2/1024)}' /proc/meminfo`; if [ -r /sys/fs/cgroup/memory/memory.limit_in_bytes ]; then CGMEM=`cat /sys/fs/cgroup/memory/memory.limit_in_bytes`; else CGMEM=`expr $${KMEMMB} \* 1024`; fi; CGMEMMB=`expr $${CGMEM} / 1024`; if [ "$${KMEMMB}" -lt "$${CGMEMMB}" ]; then echo "$${KMEMMB}"; else echo "$${CGMEMMB}"; fi)
 endif
 ifeq ($(OS),Darwin)