diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index f3a58c1fdd55e..cb64e4797d2a8 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -166,7 +166,6 @@ smp_callin(void) DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n", cpuid, current, current->active_mm)); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/arc/kernel/smp.c b/arch/arc/kernel/smp.c index 52906d3145371..db0e104d68355 100644 --- a/arch/arc/kernel/smp.c +++ b/arch/arc/kernel/smp.c @@ -189,7 +189,6 @@ void start_kernel_secondary(void) pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu); local_irq_enable(); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index ba27e184402a7..123432bb500ed 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -436,7 +436,6 @@ asmlinkage void secondary_start_kernel(void) #endif pr_debug("CPU%u: Booted secondary processor\n", cpu); - preempt_disable(); trace_hardirqs_off(); /* diff --git a/arch/arm64/include/asm/preempt.h b/arch/arm64/include/asm/preempt.h index 80e946b2abee2..e83f0982b99c1 100644 --- a/arch/arm64/include/asm/preempt.h +++ b/arch/arm64/include/asm/preempt.h @@ -23,7 +23,7 @@ static inline void preempt_count_set(u64 pc) } while (0) #define init_idle_preempt_count(p, cpu) do { \ - task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 1bcf403a8e673..92a1bbb9f3196 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -232,7 +232,6 @@ asmlinkage notrace void secondary_start_kernel(void) init_gic_priority_masking(); rcu_cpu_starting(cpu); - preempt_disable(); trace_hardirqs_off(); /* diff --git a/arch/csky/kernel/smp.c b/arch/csky/kernel/smp.c index 041d0de6a1b67..1a8d7eaf1ff71 100644 --- a/arch/csky/kernel/smp.c +++ b/arch/csky/kernel/smp.c @@ -282,7 +282,6 @@ void csky_start_secondary(void) pr_info("CPU%u Online: %s...\n", cpu, __func__); local_irq_enable(); - preempt_disable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c index 093040f7e626a..0cad990385c04 100644 --- a/arch/ia64/kernel/smpboot.c +++ b/arch/ia64/kernel/smpboot.c @@ -440,7 +440,6 @@ start_secondary (void *unused) #endif efi_map_pal_code(); cpu_init(); - preempt_disable(); smp_callin(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 48d84d5fcc361..ff25926c5458c 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -348,7 +348,6 @@ asmlinkage void start_secondary(void) */ calibrate_delay(); - preempt_disable(); cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; diff --git a/arch/openrisc/kernel/smp.c b/arch/openrisc/kernel/smp.c index 29c82ef2e207c..e4dad76066aed 100644 --- a/arch/openrisc/kernel/smp.c +++ b/arch/openrisc/kernel/smp.c @@ -134,8 +134,6 @@ asmlinkage __init void secondary_start_kernel(void) set_cpu_online(cpu, true); local_irq_enable(); - - preempt_disable(); /* * OK, it's off to the idle thread for us */ diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 10227f667c8a6..1405b603b91b6 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -302,7 +302,6 @@ void __init smp_callin(unsigned long pdce_proc) #endif smp_cpu_init(slave_id); - preempt_disable(); flush_cache_all_local(); /* start with known state */ flush_tlb_all_local(NULL); diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index aa0a35ebc04ab..91f274134884e 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1436,7 +1436,6 @@ void start_secondary(void *unused) smp_store_cpu_info(cpu); set_dec(tb_ticks_per_jiffy); rcu_cpu_starting(cpu); - preempt_disable(); cpu_callin_map[cpu] = 1; if (smp_ops->setup_cpu) diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 96167d55ed984..0b04e0eae3ab5 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -166,7 +166,6 @@ asmlinkage __visible void smp_callin(void) * Disable preemption before enabling interrupts, so we don't try to * schedule a CPU that hasn't actually started yet. */ - preempt_disable(); local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h index 6ede29907fbf7..e38480eb58faa 100644 --- a/arch/s390/include/asm/preempt.h +++ b/arch/s390/include/asm/preempt.h @@ -32,7 +32,7 @@ static inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - S390_lowcore.preempt_count = PREEMPT_ENABLED; \ + S390_lowcore.preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) @@ -91,7 +91,7 @@ static inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - S390_lowcore.preempt_count = PREEMPT_ENABLED; \ + S390_lowcore.preempt_count = PREEMPT_DISABLED; \ } while (0) static inline void set_preempt_need_resched(void) diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 791bc373418bd..7db5460553b7d 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -863,7 +863,6 @@ static void smp_init_secondary(void) set_cpu_flag(CIF_ASCE_SECONDARY); cpu_init(); rcu_cpu_starting(cpu); - preempt_disable(); init_cpu_timer(); vtime_init(); pfault_init(); diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c index 372acdc9033eb..65924d9ec2459 100644 --- a/arch/sh/kernel/smp.c +++ b/arch/sh/kernel/smp.c @@ -186,8 +186,6 @@ asmlinkage void start_secondary(void) per_cpu_trap_init(); - preempt_disable(); - notify_cpu_starting(cpu); local_irq_enable(); diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c index 50c127ab46d5b..22b148e5a5f88 100644 --- a/arch/sparc/kernel/smp_32.c +++ b/arch/sparc/kernel/smp_32.c @@ -348,7 +348,6 @@ static void sparc_start_secondary(void *arg) */ arch_cpu_pre_starting(arg); - preempt_disable(); cpu = smp_processor_id(); notify_cpu_starting(cpu); diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c index e38d8bf454e86..ae5faa1d989d2 100644 --- a/arch/sparc/kernel/smp_64.c +++ b/arch/sparc/kernel/smp_64.c @@ -138,9 +138,6 @@ void smp_callin(void) set_cpu_online(cpuid, true); - /* idle thread is expected to have preempt disabled */ - preempt_disable(); - local_irq_enable(); cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 69485ca13665f..a334dd0d7c42c 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -43,7 +43,7 @@ static __always_inline void preempt_count_set(int pc) #define init_task_preempt_count(p) do { } while (0) #define init_idle_preempt_count(p, cpu) do { \ - per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \ + per_cpu(__preempt_count, (cpu)) = PREEMPT_DISABLED; \ } while (0) /* diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 582387fc939f4..8baff500914ea 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -230,7 +230,6 @@ static void notrace start_secondary(void *unused) cpu_init_exception_handling(); cpu_init(); x86_cpuinit.early_percpu_clock_init(); - preempt_disable(); smp_callin(); enable_start_cpu0 = 0; diff --git a/arch/xtensa/kernel/smp.c b/arch/xtensa/kernel/smp.c index cd85a7a2722ba..1254da07ead1f 100644 --- a/arch/xtensa/kernel/smp.c +++ b/arch/xtensa/kernel/smp.c @@ -145,7 +145,6 @@ void secondary_start_kernel(void) cpumask_set_cpu(cpu, mm_cpumask(mm)); enter_lazy_tlb(mm, current); - preempt_disable(); trace_hardirqs_off(); calibrate_delay(); diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index d683f5e6d7913..b4d43a4af5f79 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -29,7 +29,7 @@ static __always_inline void preempt_count_set(int pc) } while (0) #define init_idle_preempt_count(p, cpu) do { \ - task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \ + task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \ } while (0) static __always_inline void set_preempt_need_resched(void) diff --git a/init/main.c b/init/main.c index 9934624dbe083..c5f7de7df91a2 100644 --- a/init/main.c +++ b/init/main.c @@ -908,11 +908,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) * time - but meanwhile we still have a functioning scheduler. */ sched_init(); - /* - * Disable preemption - early bootup scheduling is extremely - * fragile until we cpu_idle() for the first time. - */ - preempt_disable(); + if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n")) local_irq_disable(); diff --git a/kernel/fork.c b/kernel/fork.c index ec8c47c7664e0..16018dc846382 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2434,7 +2434,7 @@ static inline void init_idle_pids(struct task_struct *idle) } } -struct task_struct *fork_idle(int cpu) +struct task_struct * __init fork_idle(int cpu) { struct task_struct *task; struct kernel_clone_args args = { diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 891f85bb815b1..34a69dd29a43e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6743,7 +6743,7 @@ void show_state_filter(unsigned long state_filter) * NOTE: this function does not set the idle thread's NEED_RESCHED * flag, to make booting more robust. */ -void init_idle(struct task_struct *idle, int cpu) +void __init init_idle(struct task_struct *idle, int cpu) { struct rq *rq = cpu_rq(cpu); unsigned long flags; diff --git a/kernel/smpboot.c b/kernel/smpboot.c index f25208e8df836..e4163042c4d66 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -33,7 +33,6 @@ struct task_struct *idle_thread_get(unsigned int cpu) if (!tsk) return ERR_PTR(-ENOMEM); - init_idle(tsk, cpu); return tsk; }