Commit 7bd291ab authored by Peter Zijlstra's avatar Peter Zijlstra
Browse files

sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig 



Like many Kconfig symbols, SCHED_{SMT,CLUSTER,MC} are duplicated
across arch/*/Kconfig. Try and clean up a little.

Suggested-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarShrikanth Hegde <sshegde@linux.ibm.com>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> # powerpc
Link: https://lkml.kernel.org/r/20250826094358.GG3245006@noisy.programming.kicks-ass.net
parent 91c614f0

arch/Kconfig

+38 −0
Original line number Diff line number Diff line
@@ -41,6 +41,44 @@ config HOTPLUG_SMT 
config SMT_NUM_THREADS_DYNAMIC

	bool



config ARCH_SUPPORTS_SCHED_SMT

	bool



config ARCH_SUPPORTS_SCHED_CLUSTER

	bool



config ARCH_SUPPORTS_SCHED_MC

	bool



config SCHED_SMT

	bool "SMT (Hyperthreading) scheduler support"

	depends on ARCH_SUPPORTS_SCHED_SMT

	default y

	help

	  Improves the CPU scheduler's decision making when dealing with

	  MultiThreading at a cost of slightly increased overhead in some

	  places. If unsure say N here.



config SCHED_CLUSTER

	bool "Cluster scheduler support"

	depends on ARCH_SUPPORTS_SCHED_CLUSTER

	default y

	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.



config SCHED_MC

	bool "Multi-Core Cache (MC) scheduler support"

	depends on ARCH_SUPPORTS_SCHED_MC

	default y

	help

	  Multi-core scheduler support improves the CPU scheduler's decision

	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places. If unsure say N here.



# Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLUG_CORE_SYNC_FULL

config HOTPLUG_CORE_SYNC

	bool

arch/arm/Kconfig

+2 −16
Original line number Diff line number Diff line
@@ -941,28 +941,14 @@ config IRQSTACKS 
config ARM_CPU_TOPOLOGY

	bool "Support cpu topology definition"

	depends on SMP && CPU_V7

	select ARCH_SUPPORTS_SCHED_MC

	select ARCH_SUPPORTS_SCHED_SMT

	default y

	help

	  Support ARM cpu topology definition. The MPIDR register defines

	  affinity between processors which is then used to describe the cpu

	  topology of an ARM System.



config SCHED_MC

	bool "Multi-core scheduler support"

	depends on ARM_CPU_TOPOLOGY

	help

	  Multi-core scheduler support improves the CPU scheduler's decision

	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places. If unsure say N here.



config SCHED_SMT

	bool "SMT scheduler support"

	depends on ARM_CPU_TOPOLOGY

	help

	  Improves the CPU scheduler's decision making when dealing with

	  MultiThreading at a cost of slightly increased overhead in some

	  places. If unsure say N here.



config HAVE_ARM_SCU

	bool

	help

arch/arm64/Kconfig

+3 −23
Original line number Diff line number Diff line
@@ -108,6 +108,9 @@ config ARM64 
	select ARCH_SUPPORTS_PER_VMA_LOCK

	select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE

	select ARCH_SUPPORTS_RT

	select ARCH_SUPPORTS_SCHED_SMT

	select ARCH_SUPPORTS_SCHED_CLUSTER

	select ARCH_SUPPORTS_SCHED_MC

	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH

	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT

	select ARCH_WANT_DEFAULT_BPF_JIT
@@ -1505,29 +1508,6 @@ config CPU_LITTLE_ENDIAN 


endchoice



config SCHED_MC

	bool "Multi-core scheduler support"

	help

	  Multi-core scheduler support improves the CPU scheduler's decision

	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places. If unsure say N here.



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.



config SCHED_SMT

	bool "SMT scheduler support"

	help

	  Improves the CPU scheduler's decision making when dealing with

	  MultiThreading at a cost of slightly increased overhead in some

	  places. If unsure say N here.



config NR_CPUS

	int "Maximum number of CPUs (2-4096)"

	range 2 4096

arch/loongarch/Kconfig

+2 −17
Original line number Diff line number Diff line
@@ -70,6 +70,8 @@ config LOONGARCH 
	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS

	select ARCH_SUPPORTS_NUMA_BALANCING

	select ARCH_SUPPORTS_RT

	select ARCH_SUPPORTS_SCHED_SMT if SMP

	select ARCH_SUPPORTS_SCHED_MC  if SMP

	select ARCH_USE_BUILTIN_BSWAP

	select ARCH_USE_CMPXCHG_LOCKREF

	select ARCH_USE_MEMTEST
@@ -448,23 +450,6 @@ config EFI_STUB 
	  This kernel feature allows the kernel to be loaded directly by

	  EFI firmware without the use of a bootloader.



config SCHED_SMT

	bool "SMT scheduler support"

	depends on SMP

	default y

	help

	  Improves scheduler's performance when there are multiple

	  threads in one physical core.



config SCHED_MC

	bool "Multi-core scheduler support"

	depends on SMP

	default y

	help

	  Multi-core scheduler support improves the CPU scheduler's decision

	  making when dealing with multi-core CPU chips at a cost of slightly

	  increased overhead in some places.



config SMP

	bool "Multi-Processing support"

	help

arch/mips/Kconfig

+2 −14
Original line number Diff line number Diff line
@@ -2223,7 +2223,7 @@ config MIPS_MT_SMP 
	select SMP

	select SMP_UP

	select SYS_SUPPORTS_SMP

	select SYS_SUPPORTS_SCHED_SMT

	select ARCH_SUPPORTS_SCHED_SMT

	select MIPS_PERF_SHARED_TC_COUNTERS

	help

	  This is a kernel model which is known as SMVP. This is supported
@@ -2235,18 +2235,6 @@ config MIPS_MT_SMP 
config MIPS_MT

	bool



config SCHED_SMT

	bool "SMT (multithreading) scheduler support"

	depends on SYS_SUPPORTS_SCHED_SMT

	default n

	help

	  SMT scheduler support improves the CPU scheduler's decision making

	  when dealing with MIPS MT enabled cores at a cost of slightly

	  increased overhead in some places. If unsure say N here.



config SYS_SUPPORTS_SCHED_SMT

	bool



config SYS_SUPPORTS_MULTITHREADING

	bool
@@ -2318,7 +2306,7 @@ config MIPS_CPS 
	select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU

	select SYNC_R4K if (CEVT_R4K || CSRC_R4K)

	select SYS_SUPPORTS_HOTPLUG_CPU

	select SYS_SUPPORTS_SCHED_SMT if CPU_MIPSR6

	select ARCH_SUPPORTS_SCHED_SMT if CPU_MIPSR6

	select SYS_SUPPORTS_SMP

	select WEAK_ORDERING

	select GENERIC_IRQ_MIGRATION if HOTPLUG_CPU