# Mark Huang <mlhuang@cs.princeton.edu>
# Copyright (C) 2006 The Trustees of Princeton University
#
-# $Id: bwlimit.py,v 1.5 2006/02/27 01:58:09 mlhuang Exp $
+# $Id: bwlimit.py,v 1.6 2006/03/01 16:28:51 mlhuang Exp $
#
import sys, os, re, getopt
# "default" subclass 1:10 that is capped at the node bandwidth cap (in
# this example, 5mbit) and the "exempt" subclass 1:20 that is capped
# at bwmax (i.e., not capped). The 1:1 parent class exists only to
-# make the borrowing model work. All bandwidth is fairly shared,
-# subject to the restrictions of the class hierarchy: namely, that the
-# total bandwidth to non-exempt destinations should not exceed the
-# node bandwidth cap. The root slice has a higher priority (0) than
-# the others (1) and can thus request all of the bandwidth of that
-# subclass.
+# make the borrowing model work. All bandwidth above minimum
+# guarantees is fairly shared (in this example, slice 2 is guaranteed
+# at least 1mbit in addition to fair access to the rest), subject to
+# the restrictions of the class hierarchy: namely, that the total
+# bandwidth to non-exempt destinations should not exceed the node
+# bandwidth cap.
#
-# 1:
-# |
-# 1:1 (1gbit)
-# ______________|______________
-# | |
-# 1:10 (8bit, 5mbit) 1:20 (8bit, 1gbit)
-# | |
-# 1:1000 (8bit, 5mbit, 0), 1:2000 (8bit, 1gbit, 0),
-# 1:1001 (8bit, 5mbit, 1), 1:2001 (8bit, 1gbit, 1),
-# 1:1002 (8bit, 5mbit, 1), 1:2002 (8bit, 1gbit, 1),
-# ... ...
-# 1:1FFF (8bit, 5mbit, 1) 1:2FFF (8bit, 1gbit, 1)
+# 1:
+# |
+# 1:1 (1gbit)
+# ______________|_____________
+# | |
+# 1:10 (8bit, 5mbit) 1:20 (8bit, 1gbit)
+# | |
+# 1:1000 (8bit, 5mbit), 1:2000 (8bit, 1gbit),
+# 1:1001 (8bit, 5mbit), 1:2001 (8bit, 1gbit),
+# 1:1002 (1mbit, 5mbit), 1:2002 (1mbit, 1gbit),
+# ... ...
+# 1:1FFF (8bit, 5mbit) 1:2FFF (8bit, 1gbit)
#
default_minor = 0x1000
exempt_minor = 0x2000
# root_xid is for the root context. The root context is exempt from
-# fair sharing in both the default and exempt subclasses..
+# fair sharing in both the default and exempt subclasses. The root
+# context gets 5 shares by default.
root_xid = 0x0000
+root_share = 5
# default_xid is for unclassifiable packets. Packets should not be
# classified here very often. They can be if a slice's HTB classes are
-# deleted before its processes are.
+# deleted before its processes are. Each slice gets 1 share by
+# default.
default_xid = 0x0FFF
+default_share = 1
# See tc_util.c and http://physics.nist.gov/cuu/Units/binary.html. Be
# warned that older versions of tc interpret "kbps", "mbps", "mbit",
# Allow bwcap to be specified as a tc rate string
bwcap = get_tc_rate(bwcap)
- # Save current state (if any)
- caps = get(dev = dev)
-
# Delete root qdisc 1: if it exists. This will also automatically
# delete any child classes.
for line in tc("qdisc show dev %s" % dev):
# Set up the root class (and tell VNET what it is). Packets sent
# by root end up here and are capped at the node bandwidth
# cap.
- on(root_xid, dev, prio = 0)
+ on(root_xid, dev, share = root_share)
file("/proc/sys/vnet/root_class", "w").write("%d" % ((1 << 16) | default_minor | root_xid))
# Set up the default class. Packets that fail classification end
# up here.
- on(default_xid, dev)
-
- # Reapply bandwidth caps. If the node bandwidth cap is now lower
- # than it was before, "ceil" for each class will be lowered. If
- # the node bandwidth cap is now higher than it was before, "ceil"
- # for each class should be reapplied.
- for (xid, share, minrate, maxrate) in caps:
- if xid != root_xid and xid != default_xid:
- on(xid, dev, share = share, minrate = minrate, maxrate = maxrate)
+ on(default_xid, dev, share = default_share)
# Get the bandwidth limits for a particular slice xid as a tuple (xid,
# Apply specified bandwidth limit to the specified slice xid
-def on(xid, dev = dev, share = None, minrate = None, maxrate = None, prio = 1):
+def on(xid, dev = dev, share = None, minrate = None, maxrate = None):
# Get defaults from current state if available
cap = get(xid, dev)
if cap is not None:
# Set defaults
if share is None:
- share = 1
+ share = default_share
if minrate is None:
minrate = bwmin
else:
# Sanity checks
if maxrate > bwcap:
maxrate = bwcap
-
if minrate > maxrate:
minrate = maxrate
# Set up subclasses for the slice
- tc("class replace dev %s parent 1:10 classid 1:%x htb rate %dbit ceil %dbit quantum %d prio %d" % \
- (dev, default_minor | xid, minrate, maxrate, share * quantum, prio))
+ tc("class replace dev %s parent 1:10 classid 1:%x htb rate %dbit ceil %dbit quantum %d" % \
+ (dev, default_minor | xid, minrate, maxrate, share * quantum))
- tc("class replace dev %s parent 1:20 classid 1:%x htb rate %dbit ceil %dbit quantum %d prio %d" % \
- (dev, exempt_minor | xid, minrate, bwmax, share * quantum, prio))
+ tc("class replace dev %s parent 1:20 classid 1:%x htb rate %dbit ceil %dbit quantum %d" % \
+ (dev, exempt_minor | xid, minrate, bwmax, share * quantum))
# Attach a FIFO to each subclass, which helps to throttle back
# processes that are sending faster than the token buckets can
# are seen from this slice, they will be classified into the default
# class 1:1FFF.
def off(xid, dev = dev):
- tc("class del dev %s classid 1:%x" % (dev, default_minor | xid))
- tc("class del dev %s classid 1:%x" % (dev, exempt_minor | xid))
+ cap = get(xid, dev)
+ if cap is not None:
+ tc("class del dev %s classid 1:%x" % (dev, default_minor | xid))
+ tc("class del dev %s classid 1:%x" % (dev, exempt_minor | xid))
def usage():