From 867a6d67317b50f4a1c67807f1ad7cd58265f12b Mon Sep 17 00:00:00 2001
From: Brian O'Connor <bocon@onlab.us>
Date: Wed, 14 Aug 2013 15:04:11 -0700
Subject: [PATCH] Cleaned up sysctl and rlimit test and set Use files instead
 of sysctl to set limits

---
 mininet/util.py | 61 +++++++++++++++----------------------------------
 util/install.sh | 17 +++++++-------
 2 files changed, 28 insertions(+), 50 deletions(-)

diff --git a/mininet/util.py b/mininet/util.py
index 8c7e9ba..0c2b19b 100644
--- a/mininet/util.py
+++ b/mininet/util.py
@@ -2,7 +2,7 @@
 
 from mininet.log import output, info, error, warn
 
-from time import sleep, time
+from time import sleep
 from resource import getrlimit, setrlimit, RLIMIT_NPROC, RLIMIT_NOFILE
 from select import poll, POLLIN, POLLHUP
 from subprocess import call, check_call, Popen, PIPE, STDOUT
@@ -355,73 +355,50 @@ def pmonitor(popens, timeoutms=500, readline=True,
             yield None, ''
 
 # Other stuff we use
-#PTY_LIMIT=8192
-# Mininet: Increase open file limit
-#fs.file-max = 100000
-
-# Mininet: increase network buffer space
-#net.core.wmem_max = 16777216
-#net.core.rmem_max = 16777216
-#net.ipv4.tcp_rmem = 10240 87380 16777216
-#net.ipv4.tcp_rmem = 10240 87380 16777216
-#net.core.netdev_max_backlog = 5000
-
-# Mininet: increase arp cache size
-#net.ipv4.neigh.default.gc_thresh1 = 4096
-#net.ipv4.neigh.default.gc_thresh2 = 8192
-#net.ipv4.neigh.default.gc_thresh3 = 16384
-
-# Mininet: increase routing table size
-#net.ipv4.route.max_size=32768
-
 def sysctlTestAndSet( name, limit ):
+    "Helper function to set sysctl limits"
+    #convert non-directory names into directory names
+    if '/' not in name:
+        name = '/proc/sys/' + name.replace('.','/')
     #read limit
-    oldLimit = quietRun( 'sysctl -n %s' % name )
-    #print name, type(limit), limit
+    f = open(name, 'r+')
+    oldLimit = f.readline()
     if type( limit ) is int:
-        if int( oldLimit ) < limit:  # or True:
-            #print 'set new limit:', limit
-            output = errRun( 'sysctl -w %s=%s' % ( name, limit) )
-        #else:
-        #    print 'keep old limit'
+        #compare integer limits before overriding
+        if int( oldLimit ) < limit:
+            f.write("%d" % limit)
     else:
-        #print 'cmd:', 'sysctl', '-w', '%s=%s' % ( name, limit )
-        arg = '%s="%s"' % ( name, limit )
-        output = errRun( 'sysctl', '-w', '%s=%s' % ( name, limit ) )
-        #print output
-    #compare to limit
-    # set new limit if necessary
-    #print 'new limit:', quietRun( 'sysctl -n %s' % name )
+        #overwrite non-integer limits
+        f.write(limit)
+    f.close()
 
 def rlimitTestAndSet( name, limit ):
-    #print 'old: ', name, getrlimit( name )
-    #read limit
+    "Helper function to set rlimits"
     soft, hard = getrlimit( name )
     if soft < limit:
         hardLimit = hard if limit < hard else limit
         setrlimit( name, ( limit, hardLimit ) )
-    #compare to limit
-    # set new limit if necessary
-    #print 'new: ', name, getrlimit( name )
 
 def fixLimits():
     "Fix ridiculously small resource limits."
-    start = time()
     rlimitTestAndSet( RLIMIT_NPROC, 8192 )
     rlimitTestAndSet( RLIMIT_NOFILE, 16384 )
+    #Increase open file limit
     sysctlTestAndSet( 'fs.file-max', 10000 )
+    #Increase network buffer space
     sysctlTestAndSet( 'net.core.wmem_max', 16777216 )
     sysctlTestAndSet( 'net.core.rmem_max', 16777216 )
     sysctlTestAndSet( 'net.ipv4.tcp_rmem', '10240 87380 16777216' )
     sysctlTestAndSet( 'net.ipv4.tcp_wmem', '10240 87380 16777216' )
     sysctlTestAndSet( 'net.core.netdev_max_backlog', 5000 )
+    #Increase arp cache size
     sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh1', 4096 )
     sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh2', 8192 )
     sysctlTestAndSet( 'net.ipv4.neigh.default.gc_thresh3', 16384 )
+    #Increase routing table size
     sysctlTestAndSet( 'net.ipv4.route.max_size', 32768 )
+    #Increase number of PTYs for nodes
     sysctlTestAndSet( 'kernel.pty.max', 20000 )
-    end = time()
-    print 'limits:', start, end, end-start
 
 def mountCgroups():
     "Make sure cgroups file system is mounted"
diff --git a/util/install.sh b/util/install.sh
index e6fdf92..5ecfc16 100755
--- a/util/install.sh
+++ b/util/install.sh
@@ -144,14 +144,15 @@ function mn_deps {
         python-setuptools cgroup-bin ethtool help2man \
         pyflakes pylint pep8
 
-    # Add sysctl parameters as noted in the INSTALL file to increase kernel
-    # limits to support larger setups:
-    if ! grep Mininet /etc/sysctl.conf; then
-        echo "Adding Mininet sysctl settings"
-        sudo su -c "cat $MININET_DIR/mininet/util/sysctl_addon >> /etc/sysctl.conf"
-    fi
-    # Load new sysctl settings:
-    sudo sysctl -p
+    # TODO: remove this; it's  no longer necessary as these are check when mn starts
+    ## Add sysctl parameters as noted in the INSTALL file to increase kernel
+    ## limits to support larger setups:
+    #if ! grep Mininet /etc/sysctl.conf; then
+    #    echo "Adding Mininet sysctl settings"
+    #    sudo su -c "cat $MININET_DIR/mininet/util/sysctl_addon >> /etc/sysctl.conf"
+    #fi
+    ## Load new sysctl settings:
+    #sudo sysctl -p
 
     echo "Installing Mininet core"
     pushd $MININET_DIR/mininet