X-Git-Url: http://xvm.mit.edu/gitweb/invirt/packages/invirt-remote.git/blobdiff_plain/220b27c6a88482bf00ef06f2ee616166b81d2b53..7339891c2377d09611ba01b2f2496ae3aa151329:/host/usr/sbin/invirt-availability

diff --git a/host/usr/sbin/invirt-availability b/host/usr/sbin/invirt-availability
index 2afd5ea..93ef381 100644
--- a/host/usr/sbin/invirt-availability
+++ b/host/usr/sbin/invirt-availability
@@ -13,19 +13,23 @@ def parseUnits(s):
     return int(num) * {'kb':1, 'mb':1024}[unit.lower()]
 
 def main(argv):
+    """
+    Calculate the amount of memory available for new VMs
+    The numbers returned by xm info and xm info -c are in MB
+    The numbers in /proc/xen/balloon have nice units
+    All math is done in kilobytes for consistency
+    Output is in MB
+    """
     p = Popen(['/usr/sbin/xm', 'info'], stdout=PIPE)
     output = p.communicate()[0]
     if p.returncode != 0:
         raise RuntimeError("Command '%s' returned non-zero exit status %d"
-                           % ('invirt-availability', p.returncode)) 
+                           % ('/usr/sbin/xm info', p.returncode)) 
     xminfo = yaml.load(output, yaml.CSafeLoader)
 
-    # In kilobytes
     free_memory = int(xminfo['free_memory']) * 1024
 
-    f = open('/proc/xen/balloon', 'r')
-    ballooninfo = yaml.load(f.read())
-    f.close()
+    ballooninfo = yaml.load(open('/proc/xen/balloon', 'r').read())
     currentallocation = parseUnits(ballooninfo['Current allocation'])
     minimumtarget = parseUnits(ballooninfo['Minimum target'])
 
@@ -33,7 +37,7 @@ def main(argv):
     output = p.communicate()[0]
     if p.returncode != 0:
         raise RuntimeError("Command '%s' returned non-zero exit status %d"
-                           % ('invirt-availability', p.returncode)) 
+                           % ('/usr/sbin/xm info -c', p.returncode)) 
     xminfoc = yaml.load(output, yaml.CSafeLoader)
 
     # In kilobytes