Re: [LARTC] was tcng error; now found bug in tcc]

Re: [LARTC] was tcng error; now found bug in tcc]

[lartc]

hi all,

after slicing and dicing, i found that i had cut and pasted bad syntax,
so i have solved the problem posted in my first message.

that said, i have found an issue in 9h and 9i of tcng running on a
bi-processor with redhat-8 up2date with 2.4.20 kernel.

here's a small tcng cfg:


#define DEVICE eth0
#define UPLINK 512 

dev DEVICE {
    egress {
        htb () {
            class (rate UPLINK kbps) {
            }
        }
    }
}

[root]# cat tc.bug | tcc
tc qdisc add dev eth0 handle 1:0 root dsmark indices 1 default_index 0
tc qdisc add dev eth0 handle 2:0 parent 1:0 htb
tc class add dev eth0 parent 2:0 classid 2:1 htb rate 64000bps
------------------------------------------------------^^^^^^^^

notice that the UPLINK of 512 kbps (arguably 524288 bps) has been
incorrectly calculated as 64000 bps

similarly, the following:

#define DEVICE eth0
#define UPLINK 64 

dev DEVICE {
    egress {
        htb () {
            class (rate UPLINK kBps) {
            }
        }
    }
}

[root]# cat tc.bug | tcc
tc qdisc add dev eth0 handle 1:0 root dsmark indices 1 default_index 0
tc qdisc add dev eth0 handle 2:0 parent 1:0 htb
tc class add dev eth0 parent 2:0 classid 2:1 htb rate 64000bps
------------------------------------------------------^^^^^^^^

if i express the UPLINK in kilobytes/s, then the rate has been
incorrectly multiplied by 1000 instead equaling 64 * 8 * 1024 = 524288


have i missed something, or indeed there is a problem??

many thanks

charles

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Re: [LARTC] was tcng error; now found bug in tcc

[lartc]

hi werner,

thanks very much -- i've got it now!

btw, tcng is just great -- simply marvelous!

cheers

charles


On Thu, 2003-11-27 at 20:06, Werner Almesberger wrote:
> lartc@manchotnetworks.net wrote:
> > have i missed something, or indeed there is a problem??
> 
> No, all this should be correct - in "tc", "bps" means Bytes per
> second. And in tcng, rates and packets use the multiplier 1000,
> while bit and byte sizes use the multiplier 1024. This just
> follows what is the most common use for the respective unit.
> 
> If you don't like the 1000 multiplier, you can just
> 
> #define bps b/1s
> #define kbps kb/1s
> #define Mbps Mb/1s
> #define Gbps Gb/1s
> #define Bps B/1s
> #define kBps kB/1s
> #define MBps MB/1s
> #define GBps GB/1s
> 
> - Werner

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