Bug#890343: systemd: Debian could use the fq_codel network queuing algorithm by default

[Felipe Sateler]

On Tue, Feb 13, 2018 at 1:58 PM, Laurent Bonnaud <L.Bonnaud at laposte.net> wrote:
>
> Package: systemd
> Version: 237-2
> Severity: normal
>
>
> Dear Maintainer,
>
> by default Debian uses the pfifo_fast network queuing algorithm:
>
> # tc -s qdisc show
> [...]
> qdisc pfifo_fast 0: dev eth0 root refcnt 2 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
>  Sent 413728102 bytes 475015 pkt (dropped 0, overlimits 0 requeues 785)
>  backlog 0b 0p requeues 785
>
> The systemd source package contains this file:
>
>   ./systemd-237/sysctl.d/50-default.conf:net.core.default_qdisc = fq_codel
>
> whose purpose is to set the default queuing algorithm to fq_codel.  According to the NEWS file, this is a better alternative:
>
>         * The default sysctl.d/ snippets will now set:
>
>                 net.core.default_qdisc = fq_codel
>
>           This selects Fair Queuing Controlled Delay as the default
>           queuing discipline for network interfaces. fq_codel helps
>           fight the network bufferbloat problem. It is believed to be
>           a good default with no tuning required for most workloads.
>           Downstream distributions may override this choice. On 10Gbit
>           servers that do not do forwarding, "fq" may perform better.
>           Systems without a good clocksource should use "pfifo_fast".
>
> However the 50-default.conf file is not in the Debian binary package.
> Is this intentional or an omission?
> Could it be possible to enable fq_codel by default?
>

Changelog has this by Marco d'Itri:

>  * Do not install sysctl.d/50-default.conf because the systemd package
>    should not change kernel policies, at least until it will become
>    the only supported init system.

And it makes sense: why would some users get this but others don't?

-- 

Saludos,
Felipe Sateler