Hi Peter.
Looking at this,
https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?h=sched/core&id=9d710c5b2bb37cedf5f09ce988884fb5795e1a76
WDYT?
---
Kconfig | 38 ++++++++++++++++++++++++++++++++++++++
arm/Kconfig | 18 ++----------------
arm64/Kconfig | 26 +++-----------------------
loongarch/Kconfig | 19 ++-----------------
mips/Kconfig | 16 ++--------------
parisc/Kconfig | 9 +--------
powerpc/Kconfig | 15 +++------------
riscv/Kconfig | 9 +--------
s390/Kconfig | 8 ++------
sparc/Kconfig | 20 ++------------------
x86/Kconfig | 27 ++++-----------------------
11 files changed, 60 insertions(+), 145 deletions(-)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -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
...
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -170,6 +170,9 @@ config PPC
select ARCH_STACKWALK
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_DEBUG_PAGEALLOC if PPC_BOOK3S || PPC_8xx
+ select ARCH_SUPPORTS_SCHED_SMT if PPC64 && SMP
+ select ARCH_SUPPORTS_SCHED_MC if PPC64 && SMP
+ select SCHED_MC if ARCH_SUPPORTS_SCHED_MC
Wondering if this SCHED_MC is necessary here? shouldn't it be set by
arch/Kconfig?
nit: Also, can we have so they are still sorted?
select ARCH_SUPPORTS_SCHED_MC if PPC64 && SMP
select ARCH_SUPPORTS_SCHED_SMT if PPC64 && SMP
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_CMPXCHG_LOCKREF if PPC64
select ARCH_USE_MEMTEST
@@ -963,18 +966,6 @@ config PPC_PROT_SAO_LPAR
config PPC_COPRO_BASE
bool
-config SCHED_SMT
- bool "SMT (Hyperthreading) scheduler support"
- depends on PPC64 && SMP
- help
- SMT scheduler support improves the CPU scheduler's decision making
- when dealing with POWER5 cpus at a cost of slightly increased
- overhead in some places. If unsure say N here.
-
-config SCHED_MC
- def_bool y
- depends on PPC64 && SMP
-
config PPC_DENORMALISATION
bool "PowerPC denormalisation exception handling"
depends on PPC_BOOK3S_64
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -72,6 +72,7 @@ config RISCV
select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
select ARCH_SUPPORTS_RT
select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
+ select ARCH_SUPPORTS_SCHED_MC if SMP
select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
select ARCH_USE_MEMTEST
select ARCH_USE_QUEUED_RWLOCKS
@@ -453,14 +454,6 @@ config SMP
If you don't know what to do here, say N.
-config SCHED_MC
- bool "Multi-core scheduler support"
- depends on SMP
- 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 NR_CPUS
int "Maximum number of CPUs (2-512)"
depends on SMP
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -547,15 +547,11 @@ config NODES_SHIFT
depends on NUMA
default "1"
-config SCHED_SMT
- def_bool n
-
-config SCHED_MC
- def_bool n
-
config SCHED_TOPOLOGY
def_bool y
prompt "Topology scheduler support"
+ select ARCH_SUPPORTS_SCHED_SMT
+ select ARCH_SUPPORTS_SCHED_MC
select SCHED_SMT
select SCHED_MC
Same here. Above two are needed?
help
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -110,6 +110,8 @@ config SPARC64
select HAVE_SETUP_PER_CPU_AREA
select NEED_PER_CPU_EMBED_FIRST_CHUNK
select NEED_PER_CPU_PAGE_FIRST_CHUNK
+ select ARCH_SUPPORTS_SCHED_SMT if SMP
+ select ARCH_SUPPORTS_SCHED_MC if SMP
config ARCH_PROC_KCORE_TEXT
def_bool y
@@ -288,24 +290,6 @@ if SPARC64 || COMPILE_TEST
source "kernel/power/Kconfig"
endif
-config SCHED_SMT
- bool "SMT (Hyperthreading) scheduler support"
- depends on SPARC64 && SMP
- default y
- help
- SMT scheduler support improves the CPU scheduler's decision making
- when dealing with SPARC cpus at a cost of slightly increased overhead
- in some places. If unsure say N here.
-
-config SCHED_MC
- bool "Multi-core scheduler support"
- depends on SPARC64 && 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. If unsure say N here.
-
config CMDLINE_BOOL
bool "Default bootloader kernel arguments"
depends on SPARC64
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -330,6 +330,10 @@ config X86
imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
select HAVE_DYNAMIC_FTRACE_NO_PATCHABLE
select ARCH_SUPPORTS_PT_RECLAIM if X86_64
+ select ARCH_SUPPORTS_SCHED_SMT if SMP
+ select SCHED_SMT if SMP
Is this SCHED_SMT needed here?
+ select ARCH_SUPPORTS_SCHED_CLUSTER if SMP
+ select ARCH_SUPPORTS_SCHED_MC if SMP
config INSTRUCTION_DECODER
def_bool y
@@ -1036,29 +1040,6 @@ config NR_CPUS
This is purely to save memory: each supported CPU adds about 8KB
to the kernel image.
-config SCHED_CLUSTER
- bool "Cluster scheduler support"
- depends on SMP
- 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_SMT
- def_bool y if SMP
-
-config SCHED_MC
- def_bool y
- prompt "Multi-core scheduler support"
- depends on SMP
- 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_MC_PRIO
bool "CPU core priorities scheduler support"
depends on SCHED_MC
