Calculating the precision of the interrupt number column on every initial
show_interrupt() invocation is a pointless exercise as the underlying
maximum number of interrupts rarely changes.
Calculate it only when that number is modified and let show_interrupts()
use the cached value.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/irq/internals.h | 2 ++
kernel/irq/irqdesc.c | 10 ++++++----
kernel/irq/proc.c | 28 +++++++++++++++++++---------
3 files changed, 27 insertions(+), 13 deletions(-)
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -124,6 +124,7 @@ extern void unregister_irq_proc(unsigned
extern void register_handler_proc(unsigned int irq, struct irqaction *action);
extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
void irq_proc_update_valid(struct irq_desc *desc);
+void irq_proc_calc_prec(void);
#else
static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
static inline void unregister_irq_proc(unsigned int irq, struct irq_desc *desc) { }
@@ -132,6 +133,7 @@ static inline void register_handler_proc
static inline void unregister_handler_proc(unsigned int irq,
struct irqaction *action) { }
static inline void irq_proc_update_valid(struct irq_desc *desc) { }
+static inline void irq_proc_calc_prec(void) { }
#endif
extern bool irq_can_set_affinity_usr(unsigned int irq);
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -157,13 +157,12 @@ EXPORT_SYMBOL_GPL(irq_get_nr_irqs);
*
* Return: @nr.
*/
-unsigned int irq_set_nr_irqs(unsigned int nr)
+unsigned int __init irq_set_nr_irqs(unsigned int nr)
{
total_nr_irqs = nr;
-
+ irq_proc_calc_prec();
return nr;
}
-EXPORT_SYMBOL_GPL(irq_set_nr_irqs);
static DEFINE_MUTEX(sparse_irq_lock);
static struct maple_tree sparse_irqs = MTREE_INIT_EXT(sparse_irqs,
@@ -544,6 +543,7 @@ static bool irq_expand_nr_irqs(unsigned
if (nr > MAX_SPARSE_IRQS)
return false;
total_nr_irqs = nr;
+ irq_proc_calc_prec();
return true;
}
@@ -572,6 +572,7 @@ int __init early_irq_init(void)
desc = alloc_desc(i, node, 0, NULL, NULL);
irq_insert_desc(i, desc);
}
+ irq_proc_calc_prec();
return arch_early_irq_init();
}
@@ -592,7 +593,7 @@ int __init early_irq_init(void)
init_irq_default_affinity();
- printk(KERN_INFO "NR_IRQS: %d\n", NR_IRQS);
+ pr_info("NR_IRQS: %d\n", NR_IRQS);
count = ARRAY_SIZE(irq_desc);
@@ -602,6 +603,7 @@ int __init early_irq_init(void)
goto __free_desc_res;
}
+ irq_proc_calc_prec();
return arch_early_irq_init();
__free_desc_res:
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -457,10 +457,21 @@ int __weak arch_show_interrupts(struct s
return 0;
}
+static int irq_num_prec __read_mostly = 3;
+
#ifndef ACTUAL_NR_IRQS
# define ACTUAL_NR_IRQS total_nr_irqs
#endif
+void irq_proc_calc_prec(void)
+{
+ unsigned int prec, n;
+
+ for (prec = 3, n = 1000; prec < 10 && n <= total_nr_irqs; ++prec)
+ n *= 10;
+ WRITE_ONCE(irq_num_prec, prec);
+}
+
#define ZSTR1 " 0"
#define ZSTR1_LEN 11
#define ZSTR16 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 ZSTR1 \
@@ -499,8 +510,7 @@ void irq_proc_emit_counts(struct seq_fil
int show_interrupts(struct seq_file *p, void *v)
{
- const unsigned int nr_irqs = irq_get_nr_irqs();
- static int prec;
+ int prec = READ_ONCE(irq_num_prec);
int i = *(loff_t *) v, j;
struct irqaction *action;
@@ -514,9 +524,6 @@ int show_interrupts(struct seq_file *p,
/* print header and calculate the width of the first column */
if (i == 0) {
- for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
- j *= 10;
-
seq_printf(p, "%*s", prec + 8, "");
for_each_online_cpu(j)
seq_printf(p, "CPU%-8d", j);
@@ -552,13 +559,16 @@ int show_interrupts(struct seq_file *p,
} else {
seq_printf(p, "%8s", "None");
}
+
+ seq_putc(p, ' ');
if (desc->irq_data.domain)
- seq_printf(p, " %*lu", prec, desc->irq_data.hwirq);
+ seq_put_decimal_ull_width(p, "", desc->irq_data.hwirq, prec);
else
seq_printf(p, " %*s", prec, "");
-#ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
- seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
-#endif
+
+ if (IS_ENABLED(CONFIG_GENERIC_IRQ_SHOW_LEVEL))
+ seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
+
if (desc->name)
seq_printf(p, "-%-8s", desc->name);