On Mon, 26 Mar 2018 13:34:39 +0100 Luca Boccassi <[email protected]> wrote:
> On Sat, 2018-03-24 at 14:43 +0100, Vaclav Zindulka wrote: > > Package: iproute2 > > Version: 4.14.1-1~bpo9+1 > > Severity: normal > > > > Dear Maintainer, > > > > I found some problems in tc class show and tc filter show commands. > > We > > use tc in large scale (thousands of subnets) on multiple servers. > > Whole > > shaping system is udergoing large overview and I'm rewriting it > > almost > > from the scratch. Tc rules are one of key elements so I started to > > check > > and change its whole structure. Until now we had everything in parent > > qdisc 1:0 (all tc filter rules, tc classes). Now I decided to change > > it, > > so a lot of classes have its own hfsc qdiscs and in this qdiscs I > > create > > whole new structure of tc classes, tc filters a tc qdiscs. Let's say > > it > > is a tree within a tree. I can provide simple (prototype) bash > > script, > > which led to my discovery. (https://pastebin.com/A57x8fq5 - comments > > are > > in czech since I didn't plan to release it anywhere :-) - I can > > provide > > further info if needed. > > > > Problem is very annoying since I need to get > > stats from tc -s class show dev ...etc. > > > > 1. First problem - tc class show dev enp0s31f6 prints whole structure > > two times. I compared it with "sudo tc -s class show dev enp0s31f6" | > > grep > > -c "class" vs "sudo tc -s class show dev enp0s31f6" | sort | uniq | > > grep > > -c "class" which produces about a half of records. Reference class > > 2000:ffff (produced by my script 2000 - 4fff) is shown twice (same > > for > > 2000: root). I'm not sure about behavior of executing command twice > > in this case but it can't be defined twice for sure. Tc is veeery > > picky > > :-) > > > > 2. Second problem - tc filter show dev enp0s31f6 show just the parent > > 1:0 rules. This one is not so critical, since I don't read stats > > regularly, but for debugging it is very inconvenient since one has to > > know classId of whole parent (let's say 2000:0 qdisc in which all > > those > > filters reside). When I execute tc filter show dev enp0s31f6 parent > > 2000: (including colon :-) I get all those defined filter rules and > > hash > > tables. But not with base command. > > > > I discovered this on version 4.9 from stable stretch repository. I > > tried > > to install backport version 4.14 but resutls were exactly the same. I > > didn't try to reboot after upgrade yet tho. I'll do this after > > finishing > > this bugreport. I didn't try to compile newest version from source > > since > > I need some kind of stable solution to put it on 21 servers. > > > > What I expected was to see defined classes just once. And to see tc > > filter rules with base show command without specifying parent's > > classid > > for every hfsc qdisc containing additional rules and hash tables. > > Hi, > > Since you mentioned it's working in the same way in 4.9 to 4.14 it > doesn't look like it's a regression, so a better place to ask would > probably be netdev: http://vger.kernel.org/vger-lists.html#netdev > > Stephen, any comment on the behaviour described above? > No idea, the print code in iproute2 is just taking what kernel passes back and displays. Most likely it is in hfsc code which to be honest is not widely used by the kernel maintainers. I wouldn't be surprised if it had bugs.
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