The following commit has been merged into the irq/core branch of tip:
Commit-ID: f9ed1f7c2e26fcd19781774e310a6236d7525c11
Gitweb: https://git.kernel.org/tip/f9ed1f7c2e26fcd19781774e310a6236d7525c11
Author: David Wang <00107082@xxxxxxx>
AuthorDate: Sat, 09 Nov 2024 00:07:17 +08:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Wed, 13 Nov 2024 17:36:35 +01:00
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@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20241108160717.9547-1-00107082@xxxxxxx
---
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 d226282..f36c33b 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) {
|