sched/doc: Factorize bits between sched-energy.rst & sched-capacity.rst
Documentation/scheduler/sched-capacity.rst ought to be the canonical place to blabber about SD_ASYM_CPUCAPACITY, so remove its explanation from sched-energy.rst and point to sched-capacity.rst instead. Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20200731192016.7484-4-valentin.schneider@arm.com
This commit is contained in:
parent
65065fd70b
commit
949bcb8135
|
@ -331,16 +331,8 @@ asymmetric CPU topologies for now. This requirement is checked at run-time by
|
|||
looking for the presence of the SD_ASYM_CPUCAPACITY flag when the scheduling
|
||||
domains are built.
|
||||
|
||||
The flag is set/cleared automatically by the scheduler topology code whenever
|
||||
there are CPUs with different capacities in a root domain. The capacities of
|
||||
CPUs are provided by arch-specific code through the arch_scale_cpu_capacity()
|
||||
callback. As an example, arm and arm64 share an implementation of this callback
|
||||
which uses a combination of CPUFreq data and device-tree bindings to compute the
|
||||
capacity of CPUs (see drivers/base/arch_topology.c for more details).
|
||||
|
||||
So, in order to use EAS on your platform your architecture must implement the
|
||||
arch_scale_cpu_capacity() callback, and some of the CPUs must have a lower
|
||||
capacity than others.
|
||||
See Documentation/sched/sched-capacity.rst for requirements to be met for this
|
||||
flag to be set in the sched_domain hierarchy.
|
||||
|
||||
Please note that EAS is not fundamentally incompatible with SMP, but no
|
||||
significant savings on SMP platforms have been observed yet. This restriction
|
||||
|
|
Loading…
Reference in New Issue