Re: bond + tc regression ?

[Denys Fedoryschenko <denys@visp.net.lb>]

On Saturday 09 May 2009 01:07:27 Vladimir Ivashchenko wrote:
> > > Wow, instead of 98425b burst, its calculating 970203b.
> >
> > Kind of strange burst, something wrong there. For 1000HZ and 1 Gbit it
> > should be 126375b. You value is for 8Gbit/s.
> > What version of iproute2 you are using ( tc -V )?
>
> That was iproute2-ss080725, I think it is confused by tickless mode.
> With iproute2-ss090324 I'm getting an opposite: 1589b :)
And it is too low. Thats why i set HZ=1000
>
>
> All child classes have smaller bursts than the parent. However, there are
> two sub-classes which have ceil at 70% of parent, e.g. ~500mbit each. I
> don't know HTB internals, perhaps these two classes make the parent class
> overstretch itself.
As i remember important to keep sum of child rates lower or equal parent rate.
Sure ceil of childs must not exceed ceil of parent.
Sometimes i had mess, when i tried to play with quantum value. After all that 
i switched to HFSC which works for me flawlessly. Maybe we should give more 
attention to HTB problem with high speeds and help kernel developers spot 
problem, if there is any.

>
> By the way, I experience the same "overstretching" with hfsc. In any case,
> I prefer HTB because it reports statistics of parent classes, unlike hfsc.
Sometimes it happen when some offloading enabled on devices.
Check ethtool -k device

I think everything except rx/tx checksumming have to be off, at least for 
test.

Disable them by "ethtool -K device tso off " for example.


>
> But why it would it jump from 850mbits to 1200mbits *AFTER* I remove all
> the traffic ?
>
Well, i dont know how it is doing averaging, even maybe for 1 minute. 
I dont like it at all, and thats why i prefer HFSC. But HTB work very well in 
some setups