Subject: net: allow configuring default qdisc

Since 3.12 it has been possible to configure the default queuing
discipline via sysctl. This patch adds ability to configure the
default queue discipline in kernel configuration. This is useful for
environments where configuring the value from userspace is difficult
to manage.

The default is still the same as before (pfifo_fast) and it is
possible to change after kernel init with sysctl. This is similar
to how TCP congestion control works.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger 2017-04-13 08:40:53 -07:00 committed by David S. Miller
parent 7ca9511813
commit 8ea3e43911
2 changed files with 54 additions and 0 deletions

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@ -352,6 +352,51 @@ config NET_SCH_PLUG
To compile this code as a module, choose M here: the
module will be called sch_plug.
menuconfig NET_SCH_DEFAULT
bool "Allow override default queue discipline"
---help---
Support for selection of default queuing discipline.
Nearly all users can safely say no here, and the default
of pfifo_fast will be used. Many distributions already set
the default value via /proc/sys/net/core/default_qdisc.
If unsure, say N.
if NET_SCH_DEFAULT
choice
prompt "Default queuing discipline"
default DEFAULT_PFIFO_FAST
help
Select the queueing discipline that will be used by default
for all network devices.
config DEFAULT_FQ
bool "Fair Queue" if NET_SCH_FQ
config DEFAULT_CODEL
bool "Controlled Delay" if NET_SCH_CODEL
config DEFAULT_FQ_CODEL
bool "Fair Queue Controlled Delay" if NET_SCH_FQ_CODEL
config DEFAULT_SFQ
bool "Stochastic Fair Queue" if NET_SCH_SFQ
config DEFAULT_PFIFO_FAST
bool "Priority FIFO Fast"
endchoice
config DEFAULT_NET_SCH
string
default "pfifo_fast" if DEFAULT_PFIFO_FAST
default "fq" if DEFAULT_FQ
default "fq_codel" if DEFAULT_FQ_CODEL
default "sfq" if DEFAULT_SFQ
default "pfifo_fast"
endif
comment "Classification"
config NET_CLS

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@ -251,6 +251,15 @@ int qdisc_set_default(const char *name)
return ops ? 0 : -ENOENT;
}
#ifdef CONFIG_NET_SCH_DEFAULT
/* Set default value from kernel config */
static int __init sch_default_qdisc(void)
{
return qdisc_set_default(CONFIG_DEFAULT_NET_SCH);
}
late_initcall(sch_default_qdisc);
#endif
/* We know handle. Find qdisc among all qdisc's attached to device
* (root qdisc, all its children, children of children etc.)
* Note: caller either uses rtnl or rcu_read_lock()