sched/documentation: Document the util clamp feature

Add a document explaining the util clamp feature: what it is and
how to use it. The new document hopefully covers everything one needs to
know about uclamp.
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Qais Yousef (Google) <qyousef@layalina.io>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20221216235716.201923-1-qyousef@layalina.io
Cc: Jonathan Corbet <corbet@lwn.net>

Documentation/admin-guide/cgroup-v2.rst

@@ -619,6 +619,8 @@ process migrations.
 and is an example of this type.
 
 
+.. _cgroupv2-limits-distributor:
+
 Limits
 ------
 
@@ -635,6 +637,7 @@ process migrations.
 "io.max" limits the maximum BPS and/or IOPS that a cgroup can consume
 on an IO device and is an example of this type.
 
+.. _cgroupv2-protections-distributor:
 
 Protections
 -----------

Documentation/scheduler/index.rst

@@ -15,6 +15,7 @@ Linux Scheduler
     sched-capacity
     sched-energy
     schedutil
+    sched-util-clamp
     sched-nice-design
     sched-rt-group
     sched-stats