Messages in this thread Patch in this message | | | From | Zhang Xincheng <> | Subject | [PATCH] interrupt: discover and disable very frequent interrupts | Date | Fri, 30 Sep 2022 14:40:42 +0800 |
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From: zhangxincheng <zhangxincheng@uniontech.com>
In some cases, a peripheral's interrupt will be triggered frequently, which will keep the CPU processing the interrupt and eventually cause the RCU to report rcu_sched self-detected stall on the CPU.
[ 838.131628] rcu: INFO: rcu_sched self-detected stall on CPU [ 838.137189] rcu: 0-....: (194839 ticks this GP) idle=f02/1/0x4000000000000004 softirq=9993/9993 fqs=97428 [ 838.146912] rcu: (t=195015 jiffies g=6773 q=0) [ 838.151516] Task dump for CPU 0: [ 838.154730] systemd-sleep R running task 0 3445 1 0x0000000a
Signed-off-by: zhangxincheng <zhangxincheng@uniontech.com> Change-Id: I9c92146f2772eae383c16c8c10de028b91e07150 Signed-off-by: zhangxincheng <zhangxincheng@uniontech.com> --- include/linux/irqdesc.h | 2 ++ kernel/irq/spurious.c | 52 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+)
diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index 1cd4e36890fb..a3bd521c3557 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -102,6 +102,8 @@ struct irq_desc { int parent_irq; struct module *owner; const char *name; + u32 gap_count; + u64 gap_time; } ____cacheline_internodealigned_in_smp; #ifdef CONFIG_SPARSE_IRQ diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c index 02b2daf07441..b7162a10d92c 100644 --- a/kernel/irq/spurious.c +++ b/kernel/irq/spurious.c @@ -222,6 +222,38 @@ static void __report_bad_irq(struct irq_desc *desc, irqreturn_t action_ret) raw_spin_unlock_irqrestore(&desc->lock, flags); } +/* + * Some bad hardware will trigger interrupts very frequently, which will + * cause the CPU to process hardware interrupts all the time. So when + * we find this out, the interrupt should be disabled. + */ +static void __report_so_frequently_irq(struct irq_desc *desc, irqreturn_t action_ret) +{ + unsigned int irq = irq_desc_get_irq(desc); + struct irqaction *action; + unsigned long flags; + + printk(KERN_ERR "irq %d: triggered too frequently\n",irq); + dump_stack(); + printk(KERN_ERR "handlers:\n"); + + /* + * We need to take desc->lock here. note_interrupt() is called + * w/o desc->lock held, but IRQ_PROGRESS set. We might race + * with something else removing an action. It's ok to take + * desc->lock here. See synchronize_irq(). + */ + raw_spin_lock_irqsave(&desc->lock, flags); + for_each_action_of_desc(desc, action) { + printk(KERN_ERR "[<%p>] %pf", action->handler, action->handler); + if (action->thread_fn) + printk(KERN_CONT " threaded [<%p>] %pf", + action->thread_fn, action->thread_fn); + printk(KERN_CONT "\n"); + } + raw_spin_unlock_irqrestore(&desc->lock, flags); +} + static void report_bad_irq(struct irq_desc *desc, irqreturn_t action_ret) { static int count = 100; @@ -273,6 +305,26 @@ void note_interrupt(struct irq_desc *desc, irqreturn_t action_ret) { unsigned int irq; + if((desc->gap_count & 0xffff0000) == 0) + desc->gap_time = get_jiffies_64(); + + desc->gap_count ++; + + if((desc->gap_count & 0x0000ffff) >= 2000) { + if((get_jiffies_64() - desc->gap_time) < HZ) { + desc->gap_count += 0x00010000; + desc->gap_count &= 0xffff0000; + } else { + desc->gap_count = 0; + } + + if((desc->gap_count >> 16) > 30) { + __report_so_frequently_irq(desc, action_ret); + irq_disable(desc); + } + } + + if (desc->istate & IRQS_POLL_INPROGRESS || irq_settings_is_polled(desc)) return; -- 2.20.1
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