Merge pull request #188 from mininet/devel/fixlimits

Set sysctl limits when net starts

mininet/util.py

@@ -3,7 +3,7 @@
 from mininet.log import output, info, error, warn
 
 from time import sleep
-from resource import setrlimit, RLIMIT_NPROC, RLIMIT_NOFILE
+from resource import getrlimit, setrlimit, RLIMIT_NPROC, RLIMIT_NOFILE
 from select import poll, POLLIN, POLLHUP
 from subprocess import call, check_call, Popen, PIPE, STDOUT
 import re
@@ -355,11 +355,50 @@ def pmonitor(popens, timeoutms=500, readline=True,
             yield None, ''
 
 # Other stuff we use
+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
+    f = open( name, 'r+' )
+    oldLimit = f.readline()
+    if type( limit ) is int:
+        #compare integer limits before overriding
+        if int( oldLimit ) < limit:
+            f.write( "%d" % limit )
+    else:
+        #overwrite non-integer limits
+        f.write( limit )
+    f.close()
+
+def rlimitTestAndSet( name, limit ):
+    "Helper function to set rlimits"
+    soft, hard = getrlimit( name )
+    if soft < limit:
+        hardLimit = hard if limit < hard else limit
+        setrlimit( name, ( limit, hardLimit ) )
 
 def fixLimits():
     "Fix ridiculously small resource limits."
-    setrlimit( RLIMIT_NPROC, ( 8192, 8192 ) )
-    setrlimit( RLIMIT_NOFILE, ( 16384, 16384 ) )
+    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 )
 
 def mountCgroups():
     "Make sure cgroups file system is mounted"

util/install.sh

@@ -144,15 +144,6 @@ 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
-
     echo "Installing Mininet core"
     pushd $MININET_DIR/mininet
     sudo make install