From ae9ef58996a4447dd44aa638759f913c883ba816 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 13 Nov 2020 15:02:18 +0100 Subject: [PATCH] softirq: Move related code into one section To prepare for adding a RT aware variant of softirq serialization and processing move related code into one section so the necessary #ifdeffery is reduced to one. Signed-off-by: Thomas Gleixner Reviewed-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20201113141733.974214480@linutronix.de --- kernel/softirq.c | 109 ++++++++++++++++++++++++----------------------- 1 file changed, 55 insertions(+), 54 deletions(-) diff --git a/kernel/softirq.c b/kernel/softirq.c index 09229ad82209..617009ccd82c 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -92,6 +92,13 @@ static bool ksoftirqd_running(unsigned long pending) !__kthread_should_park(tsk); } +#ifdef CONFIG_TRACE_IRQFLAGS +DEFINE_PER_CPU(int, hardirqs_enabled); +DEFINE_PER_CPU(int, hardirq_context); +EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled); +EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context); +#endif + /* * preempt_count and SOFTIRQ_OFFSET usage: * - preempt_count is changed by SOFTIRQ_OFFSET on entering or leaving @@ -102,17 +109,11 @@ static bool ksoftirqd_running(unsigned long pending) * softirq and whether we just have bh disabled. */ -/* - * This one is for softirq.c-internal use, - * where hardirqs are disabled legitimately: - */ #ifdef CONFIG_TRACE_IRQFLAGS - -DEFINE_PER_CPU(int, hardirqs_enabled); -DEFINE_PER_CPU(int, hardirq_context); -EXPORT_PER_CPU_SYMBOL_GPL(hardirqs_enabled); -EXPORT_PER_CPU_SYMBOL_GPL(hardirq_context); - +/* + * This is for softirq.c-internal use, where hardirqs are disabled + * legitimately: + */ void __local_bh_disable_ip(unsigned long ip, unsigned int cnt) { unsigned long flags; @@ -203,6 +204,50 @@ void __local_bh_enable_ip(unsigned long ip, unsigned int cnt) } EXPORT_SYMBOL(__local_bh_enable_ip); +static inline void invoke_softirq(void) +{ + if (ksoftirqd_running(local_softirq_pending())) + return; + + if (!force_irqthreads) { +#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK + /* + * We can safely execute softirq on the current stack if + * it is the irq stack, because it should be near empty + * at this stage. + */ + __do_softirq(); +#else + /* + * Otherwise, irq_exit() is called on the task stack that can + * be potentially deep already. So call softirq in its own stack + * to prevent from any overrun. + */ + do_softirq_own_stack(); +#endif + } else { + wakeup_softirqd(); + } +} + +asmlinkage __visible void do_softirq(void) +{ + __u32 pending; + unsigned long flags; + + if (in_interrupt()) + return; + + local_irq_save(flags); + + pending = local_softirq_pending(); + + if (pending && !ksoftirqd_running(pending)) + do_softirq_own_stack(); + + local_irq_restore(flags); +} + /* * We restart softirq processing for at most MAX_SOFTIRQ_RESTART times, * but break the loop if need_resched() is set or after 2 ms. @@ -327,24 +372,6 @@ restart: current_restore_flags(old_flags, PF_MEMALLOC); } -asmlinkage __visible void do_softirq(void) -{ - __u32 pending; - unsigned long flags; - - if (in_interrupt()) - return; - - local_irq_save(flags); - - pending = local_softirq_pending(); - - if (pending && !ksoftirqd_running(pending)) - do_softirq_own_stack(); - - local_irq_restore(flags); -} - /** * irq_enter_rcu - Enter an interrupt context with RCU watching */ @@ -371,32 +398,6 @@ void irq_enter(void) irq_enter_rcu(); } -static inline void invoke_softirq(void) -{ - if (ksoftirqd_running(local_softirq_pending())) - return; - - if (!force_irqthreads) { -#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK - /* - * We can safely execute softirq on the current stack if - * it is the irq stack, because it should be near empty - * at this stage. - */ - __do_softirq(); -#else - /* - * Otherwise, irq_exit() is called on the task stack that can - * be potentially deep already. So call softirq in its own stack - * to prevent from any overrun. - */ - do_softirq_own_stack(); -#endif - } else { - wakeup_softirqd(); - } -} - static inline void tick_irq_exit(void) { #ifdef CONFIG_NO_HZ_COMMON