From f9ed1f7c2e26fcd19781774e310a6236d7525c11 Mon Sep 17 00:00:00 2001 From: David Wang <00107082@163.com> Date: Sat, 9 Nov 2024 00:07:17 +0800 Subject: [PATCH] genirq/proc: Use seq_put_decimal_ull_width() for decimal values seq_printf() is more expensive than seq_put_decimal_ull_width() due to the format string parsing costs. Profiling on a x86 8-core system indicates seq_printf() takes ~47% samples of show_interrupts(). Replacing it with seq_put_decimal_ull_width() yields almost 30% performance gain. [ tglx: Massaged changelog and fixed up coding style ] Signed-off-by: David Wang <00107082@163.com> Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20241108160717.9547-1-00107082@163.com --- kernel/irq/proc.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index d226282c5b66..f36c33bd2da4 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -495,9 +495,12 @@ int show_interrupts(struct seq_file *p, void *v) if (!desc->action || irq_desc_is_chained(desc) || !desc->kstat_irqs) goto outsparse; - seq_printf(p, "%*d: ", prec, i); - for_each_online_cpu(j) - seq_printf(p, "%10u ", desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, j) : 0); + seq_printf(p, "%*d:", prec, i); + for_each_online_cpu(j) { + unsigned int cnt = desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, j) : 0; + + seq_put_decimal_ull_width(p, " ", cnt, 10); + } raw_spin_lock_irqsave(&desc->lock, flags); if (desc->irq_data.chip) {