diff options
| -rw-r--r-- | lib/Vyatta/Qos/ShaperClass.pm | 15 | ||||
| -rw-r--r-- | lib/Vyatta/Qos/TrafficShaper.pm | 57 |
2 files changed, 67 insertions, 5 deletions
diff --git a/lib/Vyatta/Qos/ShaperClass.pm b/lib/Vyatta/Qos/ShaperClass.pm index cc42f44..4afd90c 100644 --- a/lib/Vyatta/Qos/ShaperClass.pm +++ b/lib/Vyatta/Qos/ShaperClass.pm @@ -26,6 +26,8 @@ use Vyatta::Qos::Util qw/getDsfield getRate/; use constant { AVGPKT => 1024, # Average packet size for RED calculations LATENCY => 250, # Worstcase latency for RED (ms) + + MINQUANTUM => 1000, # Lowest allowable HTB quantum }; sub new { @@ -247,18 +249,27 @@ sub get_rate { } sub gen_class { - my ( $self, $dev, $qdisc, $parent, $speed ) = @_; + my ( $self, $dev, $qdisc, $parent, $speed, $r2q ) = @_; my $rate = _getPercentRate( $self->{_rate}, $speed ); my $ceil = _getPercentRate( $self->{_ceiling}, $speed ); + my $quantum = $self->{_quantum}; + + # Hack to avoid kernel HTB message if quantum is small. + # Only occurs if link speed is high and offered bandwidth is small. + if ( defined($r2q) && !defined($quantum) && ($rate / 8) / $r2q < MINQUANTUM ) { + $quantum = MINQUANTUM; + } printf "class add dev %s parent %x:1 classid %x:%x %s", $dev, $parent, $parent, $self->{id}, $qdisc; print " rate $rate" if ($rate); print " ceil $ceil" if ($ceil); + print " quantum $quantum" if ($quantum); print " burst $self->{_burst}" if ( $self->{_burst} ); print " prio $self->{_priority}" if ( $self->{_priority} ); - print " quantum $self->{_quantum}" if ( $self->{_quantum} ); + + print "\n"; } diff --git a/lib/Vyatta/Qos/TrafficShaper.pm b/lib/Vyatta/Qos/TrafficShaper.pm index 4d43c4e..3fd687a 100644 --- a/lib/Vyatta/Qos/TrafficShaper.pm +++ b/lib/Vyatta/Qos/TrafficShaper.pm @@ -25,6 +25,14 @@ use warnings; require Vyatta::Config; require Vyatta::Qos::ShaperClass; use Vyatta::Qos::Util qw/getRate getAutoRate/; +use POSIX; + +# Kernel limits on quantum (bytes) +use constant { + MAXQUANTUM => 200000, + MINQUANTUM => 1000, +}; + # Create a new instance based on config information sub new { @@ -84,6 +92,47 @@ sub _checkClasses { } } +sub _minRate { + my ($speed, $classes) = @_; + my $min = $speed / 8; + + foreach my $class (@$classes) { + my $bps = $class->get_rate($speed) / 8; # bytes per second + + $min = $bps if $bps < $min; + } + + return $min; +} + +# Compute optimum quantum scaling factor +# quantum = Bps / r2q +# and find r2q valute such that (1000 < quantum < 200000 ) +sub _r2q { + my ($speed, $classes) = @_; + my $maxbps = $speed / 8; + my $r2q = 10; + + # need a bigger r2q if going fast than 16 mbits/sec + if ($maxbps / $r2q >= MAXQUANTUM) { + $r2q = ceil($maxbps / MAXQUANTUM); + } else { + # if there is a slow class then may need smaller value + my $minbps = _minRate($speed, $classes); + + # try and find "just right value" + while ($r2q > 1 && ($minbps / $r2q) < MINQUANTUM) { + my $next = $r2q - 1; + + # don't go too small + last if ($maxbps / $next >= MAXQUANTUM); + $r2q = $next; + } + } + + return $r2q; +} + sub commands { my ( $self, $dev ) = @_; my $rate = getAutoRate( $self->{_rate}, $dev ); @@ -142,13 +191,15 @@ sub commands { $root = "parent 1:1"; } - printf "qdisc add dev %s %s handle %x: htb default %x\n", - $dev, $root, $parent, $default->{id}; + my $r2q = _r2q($rate, $classes); + + printf "qdisc add dev %s %s handle %x: htb r2q %d default %x\n", + $dev, $root, $parent, $r2q, $default->{id}; printf "class add dev %s parent %x: classid %x:1 htb rate %s\n", $dev, $parent, $parent, $rate; foreach my $class (@$classes) { - $class->gen_class( $dev, 'htb', $parent, $rate ); + $class->gen_class( $dev, 'htb', $parent, $rate, $r2q ); $class->gen_leaf( $dev, $parent, $rate ); my $prio = 1; |