parisc: more irq statistics in /proc/interrupts

Add framework and initial values for more fine grained statistics in
/proc/interrupts.

Signed-off-by: Helge Deller <deller@gmx.de>

2 files changed, 49 insertions, 2 deletions

diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c
index 810f9cf89e48..a237e32ede19 100644
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -152,6 +152,40 @@ static struct irq_chip cpu_interrupt_type = {
         .irq_retrigger  = NULL,
 };
 
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+#define irq_stats(x)            (&per_cpu(irq_stat, x))
+
+/*
+ * /proc/interrupts printing for arch specific interrupts
+ */
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+        int j;
+
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+        seq_printf(p, "%*s: ", prec, "STK");
+        for_each_online_cpu(j)
+                seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
+        seq_printf(p, "  Kernel stack usage\n");
+#endif
+#ifdef CONFIG_SMP
+        seq_printf(p, "%*s: ", prec, "RES");
+        for_each_online_cpu(j)
+                seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
+        seq_printf(p, "  Rescheduling interrupts\n");
+        seq_printf(p, "%*s: ", prec, "CAL");
+        for_each_online_cpu(j)
+                seq_printf(p, "%10u ", irq_stats(j)->irq_call_count -
+                                        irq_stats(j)->irq_tlb_count);
+        seq_printf(p, "  Function call interrupts\n");
+        seq_printf(p, "%*s: ", prec, "TLB");
+        for_each_online_cpu(j)
+                seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
+        seq_printf(p, "  TLB shootdowns\n");
+#endif
+        return 0;
+}
+
 int show_interrupts(struct seq_file *p, void *v)
 {
         int i = *(loff_t *) v, j;
@@ -219,6 +253,9 @@ int show_interrupts(struct seq_file *p, void *v)
                 raw_spin_unlock_irqrestore(&desc->lock, flags);
         }
 
+        if (i == NR_IRQS)
+                arch_show_interrupts(p, 3);
+
         return 0;
 }
 
@@ -340,13 +377,22 @@ static inline void stack_overflow_check(struct pt_regs *regs)
         /* Our stack starts directly behind the thread_info struct. */
         unsigned long stack_start = (unsigned long) current_thread_info();
         unsigned long sp = regs->gr[30];
+        unsigned long stack_usage;
+        unsigned int *last_usage;
 
         /* if sr7 != 0, we interrupted a userspace process which we do not want
          * to check for stack overflow. We will only check the kernel stack. */
         if (regs->sr[7])
                 return;
 
-        if (likely((sp - stack_start) < (THREAD_SIZE - STACK_MARGIN)))
+        /* calculate kernel stack usage */
+        stack_usage = sp - stack_start;
+        last_usage = &per_cpu(irq_stat.kernel_stack_usage, smp_processor_id());
+
+        if (unlikely(stack_usage > *last_usage))
+                *last_usage = stack_usage;
+
+        if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN)))
                 return;
 
         pr_emerg("stackcheck: %s will most likely overflow kernel stack "
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index fd1bb1519c2b..218e20bff9d2 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -127,7 +127,7 @@ ipi_interrupt(int irq, void *dev_id)
         unsigned long flags;
 
         /* Count this now; we may make a call that never returns. */
-        p->ipi_count++;
+        inc_irq_stat(irq_call_count);
 
         mb();   /* Order interrupt and bit testing. */
 
@@ -155,6 +155,7 @@ ipi_interrupt(int irq, void *dev_id)
                                 
                         case IPI_RESCHEDULE:
                                 smp_debug(100, KERN_DEBUG "CPU%d IPI_RESCHEDULE\n", this_cpu);
+                                inc_irq_stat(irq_resched_count);
                                 scheduler_ipi();
                                 break;