ARM: SMP: provide individual IPI interrupt statistics

This separates out the individual IPI interrupt counts from the
total IPI count, which allows better visibility of what IPIs are
being used for.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 19 insertions, 6 deletions

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 269237ed76a0..fa0c5f6e1587 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -382,16 +382,28 @@ void arch_send_call_function_single_ipi(int cpu)
         smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
 }
 
+static const char *ipi_types[NR_IPI] = {
+#define S(x,s)  [x - IPI_TIMER] = s
+        S(IPI_TIMER, "Timer broadcast interrupts"),
+        S(IPI_RESCHEDULE, "Rescheduling interrupts"),
+        S(IPI_CALL_FUNC, "Function call interrupts"),
+        S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"),
+        S(IPI_CPU_STOP, "CPU stop interrupts"),
+};
+
 void show_ipi_list(struct seq_file *p, int prec)
 {
-        unsigned int cpu;
+        unsigned int cpu, i;
 
-        seq_printf(p, "%*s: ", prec, "IPI");
+        for (i = 0; i < NR_IPI; i++) {
+                seq_printf(p, "%*s%u: ", prec - 1, "IPI", i);
 
-        for_each_present_cpu(cpu)
-                seq_printf(p, "%10u ", __get_irq_stat(cpu, ipi_irqs));
+                for_each_present_cpu(cpu)
+                        seq_printf(p, "%10u ",
+                                   __get_irq_stat(cpu, ipi_irqs[i]));
 
-        seq_printf(p, " Inter-processor interrupts\n");
+                seq_printf(p, " %s\n", ipi_types[i]);
+        }
 }
 
 /*
@@ -506,7 +518,8 @@ asmlinkage void __exception do_IPI(int ipinr, struct pt_regs *regs)
         unsigned int cpu = smp_processor_id();
         struct pt_regs *old_regs = set_irq_regs(regs);
 
-        __inc_irq_stat(cpu, ipi_irqs);
+        if (ipinr >= IPI_TIMER && ipinr < IPI_TIMER + NR_IPI)
+                __inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_TIMER]);
 
         switch (ipinr) {
         case IPI_TIMER: