make test: verify that /dev/shm is big enough

Verify that /dev/shm size is >= 512M, which should be enough for `make
test' needs. If the verification fails, try to enlarge it automatically.
This helps avoid docker vpp/make test crashes (seen as SIGBUS).

Change-Id: I4e23d59ff8bf8befc320fa229fb6c9bfeb809a8f
Signed-off-by: Klement Sekera <ksekera@cisco.com>

test/Makefile

@@ -102,6 +102,7 @@ SANITY_RUN_VPP_CMD=source $(PYTHON_VENV_PATH)/bin/activate && python sanity_run_
 endif
 
 sanity: verify-no-running-vpp
+	@sys_req/dev_shm_size.sh
 	@bash -c "$(SANITY_IMPORT_VPP_PAPI_CMD) ||\
 		(echo \"*******************************************************************\" &&\
 		 echo \"* Sanity check failed, cannot import vpp_papi\" &&\

test/sys_req/dev_shm_size.sh

@@ -0,0 +1,30 @@
+#!/bin/sh
+
+# this script verifies that /dev/shm is big enough for test purposes
+# 512MB seems to be enough with room to spare at the time of writing this test
+# (motivation for this check is the default docker /dev/shm size of 64M, which
+# was occasionally overrun when running the tests)
+req_min_size_megabytes=512
+
+cur_size=`df -BM --output=size /dev/shm | awk ' NR==2 { print $1 } ' | cut -f 1 -d 'M'`
+
+if test "$V" = "2"
+then
+	echo -n "Checking /dev/shm size..."
+fi
+
+if test "$cur_size" -lt "$req_min_size_megabytes"
+then
+	echo "/dev/shm size ${cur_size}M is too small, attempting to enlarge to ${req_min_size_megabytes}M."
+	sudo mount -o remount /dev/shm -o size=512M
+	cur_size=`df -BM --output=size /dev/shm | awk ' NR==2 { print $1 } ' | cut -f 1 -d 'M'`
+	if test "$cur_size" -lt "$req_min_size_megabytes"
+	then
+		echo "Couldn't enlarge /dev/shm. Please enlarge it manually so that it's at least ${req_min_size_megabytes}M big."
+		exit 1
+	fi
+	echo "/dev/shm successfully enlarged."
+elif test "$V" = "2"
+then
+	echo "OK (current size: ${cur_size}M, required size: ${req_min_size_megabytes}M)"
+fi