[ 13/95] parisc: more irq statistics in /proc/interrupts

From: Greg Kroah-Hartman
Date: Tue Jun 25 2013 - 15:12:11 EST


3.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Helge Deller <deller@xxxxxx>

commit cd85d5514d5c4d7e78abac923fc032457d0c5091 upstream.

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

Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/parisc/include/asm/hardirq.h | 36 ++++++++++++++++++++++++++-
arch/parisc/include/asm/processor.h | 1
arch/parisc/kernel/irq.c | 48 +++++++++++++++++++++++++++++++++++-
arch/parisc/kernel/smp.c | 3 +-
arch/parisc/mm/init.c | 2 +
5 files changed, 86 insertions(+), 4 deletions(-)

--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -1,11 +1,45 @@
/* hardirq.h: PA-RISC hard IRQ support.
*
* Copyright (C) 2001 Matthew Wilcox <matthew@xxxxxx>
+ * Copyright (C) 2013 Helge Deller <deller@xxxxxx>
*/

#ifndef _PARISC_HARDIRQ_H
#define _PARISC_HARDIRQ_H

-#include <asm-generic/hardirq.h>
+#include <linux/cache.h>
+#include <linux/threads.h>
+#include <linux/irq.h>
+
+typedef struct {
+ unsigned int __softirq_pending;
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
+ unsigned int kernel_stack_usage;
+#endif
+#ifdef CONFIG_SMP
+ unsigned int irq_resched_count;
+ unsigned int irq_call_count;
+ /*
+ * irq_tlb_count is double-counted in irq_call_count, so it must be
+ * subtracted from irq_call_count when displaying irq_call_count
+ */
+ unsigned int irq_tlb_count;
+#endif
+} ____cacheline_aligned irq_cpustat_t;
+
+DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+
+#define __ARCH_IRQ_STAT
+#define __IRQ_STAT(cpu, member) (irq_stat[cpu].member)
+#define inc_irq_stat(member) this_cpu_inc(irq_stat.member)
+#define local_softirq_pending() this_cpu_read(irq_stat.__softirq_pending)
+
+#define __ARCH_SET_SOFTIRQ_PENDING
+
+#define set_softirq_pending(x) \
+ this_cpu_write(irq_stat.__softirq_pending, (x))
+#define or_softirq_pending(x) this_cpu_or(irq_stat.__softirq_pending, (x))
+
+#define ack_bad_irq(irq) WARN(1, "unexpected IRQ trap at vector %02x\n", irq)

#endif /* _PARISC_HARDIRQ_H */
--- a/arch/parisc/include/asm/processor.h
+++ b/arch/parisc/include/asm/processor.h
@@ -112,7 +112,6 @@ struct cpuinfo_parisc {
unsigned long txn_addr; /* MMIO addr of EIR or id_eid */
#ifdef CONFIG_SMP
unsigned long pending_ipi; /* bitmap of type ipi_message_type */
- unsigned long ipi_count; /* number ipi Interrupts */
#endif
unsigned long bh_count; /* number of times bh was invoked */
unsigned long prof_counter; /* per CPU profiling support */
--- a/arch/parisc/kernel/irq.c
+++ b/arch/parisc/kernel/irq.c
@@ -152,6 +152,40 @@ static struct irq_chip cpu_interrupt_typ
.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,
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(
/* 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 "
--- 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;

--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -1077,6 +1077,7 @@ void flush_tlb_all(void)
{
int do_recycle;

+ inc_irq_stat(irq_tlb_count);
do_recycle = 0;
spin_lock(&sid_lock);
if (dirty_space_ids > RECYCLE_THRESHOLD) {
@@ -1097,6 +1098,7 @@ void flush_tlb_all(void)
#else
void flush_tlb_all(void)
{
+ inc_irq_stat(irq_tlb_count);
spin_lock(&sid_lock);
flush_tlb_all_local(NULL);
recycle_sids();


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