Check for memory requirements when running regressions

Lowered the default amount of memory allocated for our Vagrant VM
so that it can be booted on systems with not a lot of RAM. In turn,
also introduced memory-limit flag to our regressions, allowing
for larger regressions to be run only if the required amount
of memory is present.

Closes #175

Vagrantfile

@@ -3,7 +3,7 @@ Vagrant.configure(2) do |config|
   project_name = File.dirname(__FILE__).split("/").last
 
   config.vm.provider "virtualbox" do |vb|
-    vb.memory = 6144 # set VM memory to 6GB
+    # vb.memory = 2048 # control VM memory (set it to 2GB)
     vb.customize ["modifyvm", :id, "--usb", "off"]
     vb.customize ["modifyvm", :id, "--usbehci", "off"]
   end
@@ -13,8 +13,8 @@ Vagrant.configure(2) do |config|
     ubuntu_config.vm.box = "minimal/trusty64"
   end
 
-  #This provision, 'fix-no-tty', gets rid of an error during build
-  #which says "==> default: stdin: is not a tty"
+  # This provision, 'fix-no-tty', gets rid of an error during build
+  # which says "==> default: stdin: is not a tty"
   config.vm.provision "fix-no-tty", type: "shell" do |s|
     s.privileged = false
     s.inline = "sudo sed -i '/tty/!s/mesg n/tty -s \\&\\& mesg n/' /root/.profile"

bin/build.sh

@@ -51,7 +51,7 @@ CONFIGURE_INSTALL_PREFIX=
 CMAKE_INSTALL_PREFIX=
 
 # Partial list of dependnecies; the rest are added depending on the platform
-DEPENDENCIES="git cmake python-yaml unzip wget"
+DEPENDENCIES="git cmake python-yaml python-psutil unzip wget"
 
 ################################################################################
 #

test/ntdrivers/config.yml

@@ -1,2 +1,3 @@
 skip: ok
 time-limit: 1600
+memory-limit: 2000

test/pthread/config.yml

@@ -1,3 +1,4 @@
+skip: ok
 verifiers: [corral]
 memory: [no-reuse-impls]
 time-limit: 300

test/regtest.py

@@ -7,6 +7,7 @@
 import signal
 import logging
 import yaml
+import psutil
 import argparse
 from os import path
 import subprocess
@@ -15,7 +16,7 @@
 import time
 import sys
 
-OVERRIDE_FIELDS = ['verifiers', 'memory', 'time-limit', 'skip']
+OVERRIDE_FIELDS = ['verifiers', 'memory', 'time-limit', 'memory-limit', 'skip']
 APPEND_FIELDS = ['flags']
 
 def bold(text):
@@ -143,6 +144,7 @@ def main():
   """
   t0 = time.time()
   num_cpus = multiprocessing.cpu_count()
+  mem_total = psutil.virtual_memory().total / (1024 * 1024)
 
   # configure the CLI
   parser = argparse.ArgumentParser()
@@ -191,6 +193,9 @@ def main():
       # get the meta data for this test
       meta = metadata(test)
 
+      if meta['memory-limit'] > mem_total:
+        continue
+
       if meta['skip'] == True:
         continue