diff --git a/arch/Kconfig b/arch/Kconfig index 45c657772362..c0a6a13b06a1 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1712,44 +1712,6 @@ config HAVE_STATIC_CALL_INLINE depends on HAVE_STATIC_CALL select OBJTOOL -config HAVE_PREEMPT_DYNAMIC - bool - -config HAVE_PREEMPT_DYNAMIC_CALL - bool - depends on HAVE_STATIC_CALL - select HAVE_PREEMPT_DYNAMIC - help - An architecture should select this if it can handle the preemption - model being selected at boot time using static calls. - - Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a - preemption function will be patched directly. - - Where an architecture does not select HAVE_STATIC_CALL_INLINE, any - call to a preemption function will go through a trampoline, and the - trampoline will be patched. - - It is strongly advised to support inline static call to avoid any - overhead. - -config HAVE_PREEMPT_DYNAMIC_KEY - bool - depends on HAVE_ARCH_JUMP_LABEL - select HAVE_PREEMPT_DYNAMIC - help - An architecture should select this if it can handle the preemption - model being selected at boot time using static keys. - - Each preemption function will be given an early return based on a - static key. This should have slightly lower overhead than non-inline - static calls, as this effectively inlines each trampoline into the - start of its callee. This may avoid redundant work, and may - integrate better with CFI schemes. - - This will have greater overhead than using inline static calls as - the call to the preemption function cannot be entirely elided. - config ARCH_WANT_LD_ORPHAN_WARN bool help diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index b5a51b0ef944..876ef299e169 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -217,7 +217,6 @@ config ARM64 select HAVE_PERF_EVENTS_NMI if ARM64_PSEUDO_NMI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP - select HAVE_PREEMPT_DYNAMIC_KEY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE select HAVE_POSIX_CPU_TIMERS_TASK_WORK diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index a21f51e5815e..9480ccf73b26 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -170,7 +170,6 @@ config LOONGARCH select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_POSIX_CPU_TIMERS_TASK_WORK - select HAVE_PREEMPT_DYNAMIC_KEY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC select HAVE_RETHOOK diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2580e27e4328..143381d267ce 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -279,7 +279,6 @@ config PPC select HAVE_PERF_EVENTS_NMI if PPC64 select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP - select HAVE_PREEMPT_DYNAMIC_KEY select HAVE_POSIX_CPU_TIMERS_TASK_WORK select HAVE_RETHOOK if KPROBES select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index f8e26c4bed2b..66096a050f88 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -195,7 +195,6 @@ config RISCV select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_POSIX_CPU_TIMERS_TASK_WORK - select HAVE_PREEMPT_DYNAMIC_KEY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RETHOOK select HAVE_RSEQ diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 4b51bc6e8948..2682a2bacc58 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -246,7 +246,6 @@ config S390 select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP select HAVE_POSIX_CPU_TIMERS_TASK_WORK - select HAVE_PREEMPT_DYNAMIC_KEY select HAVE_REGS_AND_STACK_ACCESS_API select HAVE_RELIABLE_STACKTRACE select HAVE_RETHOOK diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 15fd9ec5ecac..5a84998b6021 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -297,7 +297,6 @@ config X86 select HAVE_STACK_VALIDATION if HAVE_OBJTOOL select HAVE_STATIC_CALL select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL - select HAVE_PREEMPT_DYNAMIC_CALL select HAVE_RSEQ select HAVE_RUST if X86_64 select HAVE_SYSCALL_TRACEPOINTS diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt index 68f321841c2e..985aea617cfe 100644 --- a/kernel/Kconfig.preempt +++ b/kernel/Kconfig.preempt @@ -132,11 +132,9 @@ config PREEMPTION config PREEMPT_DYNAMIC bool "Preemption behaviour defined on boot" - depends on HAVE_PREEMPT_DYNAMIC depends on ARCH_HAS_PREEMPT_LAZY - select JUMP_LABEL if HAVE_PREEMPT_DYNAMIC_KEY select PREEMPT_BUILD - default y if HAVE_PREEMPT_DYNAMIC_CALL + default y help This option allows to define the preemption model on the kernel command line parameter and thus override the default preemption @@ -146,9 +144,7 @@ config PREEMPT_DYNAMIC provide a pre-built kernel binary to reduce the number of kernel flavors they offer while still offering different usecases. - The runtime overhead is negligible with HAVE_STATIC_CALL_INLINE enabled - but if runtime patching is not available for the specific architecture - then the potential overhead should be considered. + The runtime overhead is negligible. Interesting if you want the same pre-built kernel should be used for both Server and Desktop workloads. diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0e9022f2d05d..05923200ef40 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7886,16 +7886,6 @@ int sched_dynamic_mode(const char *str) # define preempt_dynamic_key_enable(f) static_key_enable(&sk_dynamic_##f.key) # define preempt_dynamic_key_disable(f) static_key_disable(&sk_dynamic_##f.key) -# if defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL) -# define preempt_dynamic_enable(f) static_call_update(f, f##_dynamic_enabled) -# define preempt_dynamic_disable(f) static_call_update(f, f##_dynamic_disabled) -# elif defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY) -# define preempt_dynamic_enable(f) preempt_dynamic_key_enable(f) -# define preempt_dynamic_disable(f) preempt_dynamic_key_disable(f) -# else -# error "Unsupported PREEMPT_DYNAMIC mechanism" -# endif - static DEFINE_MUTEX(sched_dynamic_mutex); static void __sched_dynamic_update(int mode)