[PATCH AUTOSEL 6.6 11/23] LoongArch/irq: Use seq_put_decimal_ull_width() for decimal values

From: Sasha Levin
Date: Wed Dec 11 2024 - 14:01:29 EST


From: David Wang <00107082@xxxxxxx>

[ Upstream commit ad2a05a6d287aef7e069c06e329f1355756415c2 ]

Performance improvement for reading /proc/interrupts on LoongArch.

On a system with n CPUs and m interrupts, there will be n*m decimal
values yielded via seq_printf(.."%10u "..) which is less efficient than
seq_put_decimal_ull_width(), stress reading /proc/interrupts indicates
~30% performance improvement with this patch (and its friends).

Signed-off-by: David Wang <00107082@xxxxxxx>
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/loongarch/kernel/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index 9dbe7907a9612..a3e154978ac9d 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -83,7 +83,7 @@ void show_ipi_list(struct seq_file *p, int prec)
for (i = 0; i < NR_IPI; i++) {
seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >= 4 ? " " : "");
for_each_online_cpu(cpu)
- seq_printf(p, "%10u ", per_cpu(irq_stat, cpu).ipi_irqs[i]);
+ seq_put_decimal_ull_width(p, " ", per_cpu(irq_stat, cpu).ipi_irqs[i], 10);
seq_printf(p, " LoongArch %d %s\n", i + 1, ipi_types[i]);
}
}
--
2.43.0