On Thu, Dec 06, 2001 at 08:28:07PM +0100, Stefan Rompf wrote: > Hi, > > I'm experimenting using the HTB queueing discipline for traffic shaping. > However, it is not really exact. Currently, I try this setup: > > tc qdisc add dev eth0 root handle 1: htb default 3 > > tc class add dev eth0 parent 1: classid 1:1 htb rate 20Mbit burst 4kB > tc qdisc add dev eth0 parent 1:1 sfq Raise burst, for 20Mbit it needs to be at least 20kbyte! > The network adaptor is connected to a 100MBit switch. When testing with > netio, I can send up to 370kB/sec through class 1:2 and up to 2,4MB/sec > via class 1:1, both measured by one/multiple instances of netio and the > rate output of "tc -s class dev eth0". This effect occurs with Linux > 2.4.16, kernel either compiled with HZ set to 100 or 1024, and of The rate output of tc -s class is not that reliable. > tbf seems not to be able to do exact rate limiting, too. Anything wrong > in my configuration, or am I just taking false statistics? Both I think. There are some indications that raising HZ may not work, as it may not raise the resolution of the timers in the Linux Kernel - I am investigating this! So try keeping HZ stable, and raising the size of your bucket. Regards, bert -- http://www.PowerDNS.com Versatile DNS Software & Services Trilab The Technology People Netherlabs BV / Rent-a-Nerd.nl - Nerd Available - 'SYN! .. SYN|ACK! .. ACK!' - the mating call of the internet
