Subject: Re: [PATCH trivial] net: add bbr to config DEFAULT_TCP_CONG

From: Markus Trippelsdorf <[email-masked]>
Date: Fri, 14 Oct 2016 10:07:16 +0200

On 2016.10.14 at 09:43 +0200, Eric Dumazet wrote:
> On Fri, 2016-10-14 at 09:33 +0200, Markus Trippelsdorf wrote:
> > While playing with BBR I noticed that it was missing in the list of
> > possible config DEFAULT_TCP_CONG choices. Fixed thusly.
> > 
> > Signed-off-by: Markus Trippelsdorf <[email-masked]>
> > 
> > diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
> > index 300b06888fdf..b54b3ca939db 100644
> > --- a/net/ipv4/Kconfig
> > +++ b/net/ipv4/Kconfig
> > @@ -715,6 +715,7 @@ config DEFAULT_TCP_CONG
> >  	default "reno" if DEFAULT_RENO
> >  	default "dctcp" if DEFAULT_DCTCP
> >  	default "cdg" if DEFAULT_CDG
> > +	default "bbr" if DEFAULT_BBR
> >  	default "cubic"
> 
> Not sure if we want this at this moment.
> 
> BBR needs FQ packet scheduler, and this is not exactly trivial to
> achieve.

For a start, it could be automatically selected:

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index 300b06888fdf..845d8d3e9e27 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -642,6 +642,8 @@ config TCP_CONG_CDG
 
 config TCP_CONG_BBR
 	tristate "BBR TCP"
+	select NET_SCHED
+	select NET_SCH_FQ
 	default n
 	---help---
 
-- 
Markus