diff options
| -rw-r--r-- | arch/mips/mm/init.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 4 | ||||
| -rw-r--r-- | include/asm-generic/preempt.h | 35 | ||||
| -rw-r--r-- | include/linux/hardirq.h | 8 | ||||
| -rw-r--r-- | include/linux/preempt.h | 106 | ||||
| -rw-r--r-- | include/linux/sched.h | 5 | ||||
| -rw-r--r-- | include/linux/uaccess.h | 8 | ||||
| -rw-r--r-- | kernel/context_tracking.c | 2 | ||||
| -rw-r--r-- | kernel/sched/core.c | 29 | ||||
| -rw-r--r-- | kernel/softirq.c | 14 |
10 files changed, 113 insertions, 103 deletions
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c index e205ef598e97..12156176c7ca 100644 --- a/arch/mips/mm/init.c +++ b/arch/mips/mm/init.c @@ -124,7 +124,7 @@ void *kmap_coherent(struct page *page, unsigned long addr) BUG_ON(Page_dcache_dirty(page)); - inc_preempt_count(); + pagefault_disable(); idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1); #ifdef CONFIG_MIPS_MT_SMTC idx += FIX_N_COLOURS * smp_processor_id() + @@ -193,8 +193,7 @@ void kunmap_coherent(void) write_c0_entryhi(old_ctx); EXIT_CRITICAL(flags); #endif - dec_preempt_count(); - preempt_check_resched(); + pagefault_enable(); } void copy_user_highpage(struct page *to, struct page *from, diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 8c8093b146ca..729aa779ff75 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -88,7 +88,7 @@ static inline void conditional_sti(struct pt_regs *regs) static inline void preempt_conditional_sti(struct pt_regs *regs) { - inc_preempt_count(); + preempt_count_inc(); if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); } @@ -103,7 +103,7 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) local_irq_disable(); - dec_preempt_count(); + preempt_count_dec(); } static int __kprobes diff --git a/include/asm-generic/preempt.h b/include/asm-generic/preempt.h index 8100b1ec1715..82d958fc3823 100644 --- a/include/asm-generic/preempt.h +++ b/include/asm-generic/preempt.h @@ -65,4 +65,39 @@ static __always_inline bool test_preempt_need_resched(void) return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED); } +/* + * The various preempt_count add/sub methods + */ + +static __always_inline void __preempt_count_add(int val) +{ + *preempt_count_ptr() += val; +} + +static __always_inline void __preempt_count_sub(int val) +{ + *preempt_count_ptr() -= val; +} + +static __always_inline bool __preempt_count_dec_and_test(void) +{ + return !--*preempt_count_ptr(); +} + +/* + * Returns true when we need to resched -- even if we can not. + */ +static __always_inline bool need_resched(void) +{ + return unlikely(test_preempt_need_resched()); +} + +/* + * Returns true when we need to resched and can (barring IRQ state). + */ +static __always_inline bool should_resched(void) +{ + return unlikely(!*preempt_count_ptr()); +} + #endif /* __ASM_PREEMPT_H */ diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 1e041063b226..d9cf963ac832 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -33,7 +33,7 @@ extern void rcu_nmi_exit(void); #define __irq_enter() \ do { \ account_irq_enter_time(current); \ - add_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_add(HARDIRQ_OFFSET); \ trace_hardirq_enter(); \ } while (0) @@ -49,7 +49,7 @@ extern void irq_enter(void); do { \ trace_hardirq_exit(); \ account_irq_exit_time(current); \ - sub_preempt_count(HARDIRQ_OFFSET); \ + preempt_count_sub(HARDIRQ_OFFSET); \ } while (0) /* @@ -62,7 +62,7 @@ extern void irq_exit(void); lockdep_off(); \ ftrace_nmi_enter(); \ BUG_ON(in_nmi()); \ - add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_add(NMI_OFFSET + HARDIRQ_OFFSET); \ rcu_nmi_enter(); \ trace_hardirq_enter(); \ } while (0) @@ -72,7 +72,7 @@ extern void irq_exit(void); trace_hardirq_exit(); \ rcu_nmi_exit(); \ BUG_ON(!in_nmi()); \ - sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \ + preempt_count_sub(NMI_OFFSET + HARDIRQ_OFFSET); \ ftrace_nmi_exit(); \ lockdep_on(); \ } while (0) diff --git a/include/linux/preempt.h b/include/linux/preempt.h index df8e245e8729..2343d8715299 100644 --- a/include/linux/preempt.h +++ b/include/linux/preempt.h @@ -18,97 +18,86 @@ #include <asm/preempt.h> #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER) - extern void add_preempt_count(int val); - extern void sub_preempt_count(int val); +extern void preempt_count_add(int val); +extern void preempt_count_sub(int val); +#define preempt_count_dec_and_test() ({ preempt_count_sub(1); should_resched(); }) #else -# define add_preempt_count(val) do { *preempt_count_ptr() += (val); } while (0) -# define sub_preempt_count(val) do { *preempt_count_ptr() -= (val); } while (0) +#define preempt_count_add(val) __preempt_count_add(val) +#define preempt_count_sub(val) __preempt_count_sub(val) +#define preempt_count_dec_and_test() __preempt_count_dec_and_test() #endif -#define inc_preempt_count() add_preempt_count(1) -#define dec_preempt_count() sub_preempt_count(1) - -#ifdef CONFIG_PREEMPT - -asmlinkage void preempt_schedule(void); - -#define preempt_check_resched() \ -do { \ - if (unlikely(!*preempt_count_ptr())) \ - preempt_schedule(); \ -} while (0) - -#ifdef CONFIG_CONTEXT_TRACKING - -void preempt_schedule_context(void); - -#define preempt_check_resched_context() \ -do { \ - if (unlikely(!*preempt_count_ptr())) \ - preempt_schedule_context(); \ -} while (0) -#else - -#define preempt_check_resched_context() preempt_check_resched() - -#endif /* CONFIG_CONTEXT_TRACKING */ - -#else /* !CONFIG_PREEMPT */ - -#define preempt_check_resched() do { } while (0) -#define preempt_check_resched_context() do { } while (0) - -#endif /* CONFIG_PREEMPT */ +#define __preempt_count_inc() __preempt_count_add(1) +#define __preempt_count_dec() __preempt_count_sub(1) +#define preempt_count_inc() preempt_count_add(1) +#define preempt_count_dec() preempt_count_sub(1) #ifdef CONFIG_PREEMPT_COUNT #define preempt_disable() \ do { \ - inc_preempt_count(); \ + preempt_count_inc(); \ barrier(); \ } while (0) #define sched_preempt_enable_no_resched() \ do { \ barrier(); \ - dec_preempt_count(); \ + preempt_count_dec(); \ } while (0) -#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#define preempt_enable_no_resched() sched_preempt_enable_no_resched() +#ifdef CONFIG_PREEMPT +asmlinkage void preempt_schedule(void); #define preempt_enable() \ do { \ - preempt_enable_no_resched(); \ - preempt_check_resched(); \ + barrier(); \ + if (unlikely(preempt_count_dec_and_test())) \ + preempt_schedule(); \ } while (0) -/* For debugging and tracer internals only! */ -#define add_preempt_count_notrace(val) \ - do { *preempt_count_ptr() += (val); } while (0) -#define sub_preempt_count_notrace(val) \ - do { *preempt_count_ptr() -= (val); } while (0) -#define inc_preempt_count_notrace() add_preempt_count_notrace(1) -#define dec_preempt_count_notrace() sub_preempt_count_notrace(1) +#define preempt_check_resched() \ +do { \ + if (should_resched()) \ + preempt_schedule(); \ +} while (0) + +#else +#define preempt_enable() preempt_enable_no_resched() +#define preempt_check_resched() do { } while (0) +#endif #define preempt_disable_notrace() \ do { \ - inc_preempt_count_notrace(); \ + __preempt_count_inc(); \ barrier(); \ } while (0) #define preempt_enable_no_resched_notrace() \ do { \ barrier(); \ - dec_preempt_count_notrace(); \ + __preempt_count_dec(); \ } while (0) -/* preempt_check_resched is OK to trace */ +#ifdef CONFIG_PREEMPT + +#ifdef CONFIG_CONTEXT_TRACKING +asmlinkage void preempt_schedule_context(void); +#else +#define preempt_schedule_context() preempt_schedule() +#endif + #define preempt_enable_notrace() \ do { \ - preempt_enable_no_resched_notrace(); \ - preempt_check_resched_context(); \ + barrier(); \ + if (unlikely(__preempt_count_dec_and_test())) \ + preempt_schedule_context(); \ } while (0) +#else +#define preempt_enable_notrace() preempt_enable_no_resched_notrace() +#endif #else /* !CONFIG_PREEMPT_COUNT */ @@ -118,10 +107,11 @@ do { \ * that can cause faults and scheduling migrate into our preempt-protected * region. */ -#define preempt_disable() barrier() +#define preempt_disable() barrier() #define sched_preempt_enable_no_resched() barrier() -#define preempt_enable_no_resched() barrier() -#define preempt_enable() barrier() +#define preempt_enable_no_resched() barrier() +#define preempt_enable() barrier() +#define preempt_check_resched() do { } while (0) #define preempt_disable_notrace() barrier() #define preempt_enable_no_resched_notrace() barrier() diff --git a/include/linux/sched.h b/include/linux/sched.h index 9fa151fb968e..06ac17c7e639 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2409,11 +2409,6 @@ static inline int signal_pending_state(long state, struct task_struct *p) return (state & TASK_INTERRUPTIBLE) || __fatal_signal_pending(p); } -static inline int need_resched(void) -{ - return unlikely(test_preempt_need_resched()); -} - /* * cond_resched() and cond_resched_lock(): latency reduction via * explicit rescheduling in places that are safe. The return diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 5ca0951e1855..9d8cf056e661 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -15,7 +15,7 @@ */ static inline void pagefault_disable(void) { - inc_preempt_count(); + preempt_count_inc(); /* * make sure to have issued the store before a pagefault * can hit. @@ -30,11 +30,7 @@ static inline void pagefault_enable(void) * the pagefault handler again. */ barrier(); - dec_preempt_count(); - /* - * make sure we do.. - */ - barrier(); + preempt_count_dec(); preempt_check_resched(); } diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 247091bf0587..013161f1c807 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -111,7 +111,7 @@ void context_tracking_user_enter(void) * instead of preempt_schedule() to exit user context if needed before * calling the scheduler. */ -void __sched notrace preempt_schedule_context(void) +asmlinkage void __sched notrace preempt_schedule_context(void) { enum ctx_state prev_ctx; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0ba4e4192390..9c84a9ab1892 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2219,7 +2219,7 @@ notrace unsigned long get_parent_ip(unsigned long addr) #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ defined(CONFIG_PREEMPT_TRACER)) -void __kprobes add_preempt_count(int val) +void __kprobes preempt_count_add(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2228,7 +2228,7 @@ void __kprobes add_preempt_count(int val) if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) return; #endif - add_preempt_count_notrace(val); + __preempt_count_add(val); #ifdef CONFIG_DEBUG_PREEMPT /* * Spinlock count overflowing soon? @@ -2239,9 +2239,9 @@ void __kprobes add_preempt_count(int val) if (preempt_count() == val) trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); } -EXPORT_SYMBOL(add_preempt_count); +EXPORT_SYMBOL(preempt_count_add); -void __kprobes sub_preempt_count(int val) +void __kprobes preempt_count_sub(int val) { #ifdef CONFIG_DEBUG_PREEMPT /* @@ -2259,9 +2259,9 @@ void __kprobes sub_preempt_count(int val) if (preempt_count() == val) trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); - sub_preempt_count_notrace(val); + __preempt_count_sub(val); } -EXPORT_SYMBOL(sub_preempt_count); +EXPORT_SYMBOL(preempt_count_sub); #endif @@ -2525,9 +2525,9 @@ asmlinkage void __sched notrace preempt_schedule(void) return; do { - add_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count_notrace(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -2554,11 +2554,11 @@ asmlinkage void __sched preempt_schedule_irq(void) prev_state = exception_enter(); do { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); local_irq_enable(); __schedule(); local_irq_disable(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); /* * Check again in case we missed a preemption opportunity @@ -3798,16 +3798,11 @@ SYSCALL_DEFINE0(sched_yield) return 0; } -static inline int should_resched(void) -{ - return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); -} - static void __cond_resched(void) { - add_preempt_count(PREEMPT_ACTIVE); + __preempt_count_add(PREEMPT_ACTIVE); __schedule(); - sub_preempt_count(PREEMPT_ACTIVE); + __preempt_count_sub(PREEMPT_ACTIVE); } int __sched _cond_resched(void) diff --git a/kernel/softirq.c b/kernel/softirq.c index a90de70cf1f3..3e88612fc87e 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -100,13 +100,13 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) raw_local_irq_save(flags); /* - * The preempt tracer hooks into add_preempt_count and will break + * The preempt tracer hooks into preempt_count_add and will break * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET * is set and before current->softirq_enabled is cleared. * We must manually increment preempt_count here and manually * call the trace_preempt_off later. */ - add_preempt_count_notrace(cnt); + __preempt_count_add(cnt); /* * Were softirqs turned off above: */ @@ -120,7 +120,7 @@ static void __local_bh_disable(unsigned long ip, unsigned int cnt) #else /* !CONFIG_TRACE_IRQFLAGS */ static inline void __local_bh_disable(unsigned long ip, unsigned int cnt) { - add_preempt_count(cnt); + preempt_count_add(cnt); barrier(); } #endif /* CONFIG_TRACE_IRQFLAGS */ @@ -139,7 +139,7 @@ static void __local_bh_enable(unsigned int cnt) if (softirq_count() == cnt) trace_softirqs_on(_RET_IP_); - sub_preempt_count(cnt); + preempt_count_sub(cnt); } /* @@ -169,12 +169,12 @@ static inline void _local_bh_enable_ip(unsigned long ip) * Keep preemption disabled until we are done with * softirq processing: */ - sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1); + preempt_count_sub(SOFTIRQ_DISABLE_OFFSET - 1); if (unlikely(!in_interrupt() && local_softirq_pending())) do_softirq(); - dec_preempt_count(); + preempt_count_dec(); #ifdef CONFIG_TRACE_IRQFLAGS local_irq_enable(); #endif @@ -360,7 +360,7 @@ void irq_exit(void) account_irq_exit_time(current); trace_hardirq_exit(); - sub_preempt_count(HARDIRQ_OFFSET); + preempt_count_sub(HARDIRQ_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); |