README: mention fq_codel

In 2014, systemd started choosing fq_codel as the default_qdisc in order to fight internet bufferbloat.

https://github.com/systemd/systemd/commit/e6c253e363dee77ef7e5c5f44c4ca55cded3fd47
https://github.com/systemd/systemd/commit/fa98c99ea7f7c5bec3962fa52f4d3496a9777024

While the subsequent change made this change no longer trigger warnings if fq_codel wasn't present, it is still recommended to have this enabled.  Add the necessary kernel configuration to the documentation.

diff --git a/README b/README
index 3b62e369fa8373ac2fcf8f27cd503de951a8112d..e41ab1ab7d3dd59c806ebd0498fe57053f9ccecf 100644 (file)
--- a/README
+++ b/README
@@ -98,6 +98,8 @@ REQUIREMENTS:
           CONFIG_SECCOMP_FILTER (required for seccomp support)
           CONFIG_KCMP (for the kcmp() syscall, used to be under
                        CONFIG_CHECKPOINT_RESTORE before ~5.12)
+          CONFIG_NET_SCHED
+          CONFIG_NET_SCH_FQ_CODEL
 
         Required for CPUShares= in resource control unit settings:
           CONFIG_CGROUP_SCHED