On Sat, Oct 02, 2021 at 08:09:58PM +1300, Barry Song wrote: > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index 7e4651a1aaf4..86821e83b935 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -993,8 +993,13 @@ config SCHED_CLUSTER > bool "Cluster scheduler support" > help > Cluster scheduler support improves the CPU scheduler's decision > + making when dealing with machines that have clusters of CPUs. > + Cluster usually means a couple of CPUs which are placed closely > + by sharing mid-level caches, last-level cache tags or internal > + busses. For example, on Hisilicon Kunpeng920, each 4 CPUs share > + LLC cache tags. This feature isn't a universal win because it > + can bring a cost of slightly increased overhead in some places. > + If unsure say N here. > > config SCHED_SMT > bool "SMT scheduler support" > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index bd27b1cdac34..940eb1fe0abb 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1002,12 +1002,17 @@ config NR_CPUS > to the kernel image. > > config SCHED_CLUSTER > + def_bool y > + prompt "Cluster scheduler support" > help > Cluster scheduler support improves the CPU scheduler's decision > + making when dealing with machines that have clusters of CPUs. > + Cluster usually means a couple of CPUs which are placed closely > + by sharing mid-level caches, last-level cache tags or internal > + busses. For example, on x86 Jacobsville, each 4 CPUs share one > + L2 cache. This feature isn't a universal win because it can bring > + a cost of slightly increased overhead in some places. If unsure > + say N here. That is a really odd addition to a default-y feature. How about I make both: help Cluster scheduler support improves the CPU scheduler's decision making when dealing with machines that have clusters of CPUs. Cluster usually means a couple of CPUs which are placed closely by sharing mid-level caches, last-level cache tags or internal busses.
