diff options
Diffstat (limited to 'kernel/softirq.c')
| -rw-r--r-- | kernel/softirq.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index 479e4436f787..9029227e5f57 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -57,6 +57,13 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp DEFINE_PER_CPU(struct task_struct *, ksoftirqd); +/* + * active_softirqs -- per cpu, a mask of softirqs that are being handled, + * with the expectation that approximate answers are acceptable and therefore + * no synchronization. + */ +DEFINE_PER_CPU(__u32, active_softirqs); + const char * const softirq_to_name[NR_SOFTIRQS] = { "HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL", "TASKLET", "SCHED", "HRTIMER", "RCU" @@ -227,6 +234,8 @@ static inline bool lockdep_softirq_start(void) { return false; } static inline void lockdep_softirq_end(bool in_hardirq) { } #endif +#define long_softirq_pending() (local_softirq_pending() & LONG_SOFTIRQ_MASK) +#define defer_for_rt() (long_softirq_pending() && cpupri_check_rt()) asmlinkage __visible void __do_softirq(void) { unsigned long end = jiffies + MAX_SOFTIRQ_TIME; @@ -253,6 +262,7 @@ asmlinkage __visible void __do_softirq(void) restart: /* Reset the pending bitmask before enabling irqs */ set_softirq_pending(0); + __this_cpu_write(active_softirqs, pending); local_irq_enable(); @@ -282,12 +292,14 @@ restart: pending >>= softirq_bit; } + __this_cpu_write(active_softirqs, 0); rcu_bh_qs(); local_irq_disable(); pending = local_softirq_pending(); if (pending) { if (time_before(jiffies, end) && !need_resched() && + !defer_for_rt() && --max_restart) goto restart; @@ -340,7 +352,7 @@ void irq_enter(void) static inline void invoke_softirq(void) { - if (!force_irqthreads) { + if (!force_irqthreads && !defer_for_rt()) { #ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK /* * We can safely execute softirq on the current stack if |