Re: [PATCH] net: sched: make default fifo qdiscs appear in the dump

From: Eric Dumazet
Date: Fri Oct 21 2016 - 07:37:08 EST


On Fri, 2016-10-21 at 10:45 +0200, Jiri Kosina wrote:
> The original reason [1] for having hidden qdiscs (potential scalability
> issues in qdisc_match_from_root() with single linked list in case of large
> amount of qdiscs) has been invalidated by 59cc1f61f0 ("net: sched: convert
> qdisc linked list to hashtable").
>
> This allows us for bringing more clarity and determinism into the dump by
> making default pfifo qdiscs visible.
>
> [1] http://lkml.kernel.org/r/1460732328.10638.74.camel@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
> ---

Some of us are dealing with huge HTB hierarchies, so adding default fifo
in the dump will add more data pumped from the kernel.

BwE [1] for instance dumps qdisc/classes every 5 seconds.

I guess we'll need to not pull this patch in our kernels.

This reminds me of an HTB patch to avoid dumping rate estimates for HTB.

I will send it today.

[1]
http://static.googleusercontent.com/media/research.google.com/en//pubs/archive/43838.pdf