linux-kernel - [PATCH AUTOSEL 6.6 11/23] LoongArch/irq: Use seq_put_decimal_ull

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Message-ID: <20241211185214.3841978-11-sashal@kernel.org>
Date: Wed, 11 Dec 2024 13:51:48 -0500
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: David Wang <00107082@....com>,
	Huacai Chen <chenhuacai@...ngson.cn>,
	Sasha Levin <sashal@...nel.org>,
	chenhuacai@...nel.org,
	maobibo@...ngson.cn,
	tglx@...utronix.de,
	lvjianmin@...ngson.cn,
	zhangtianyang@...ngson.cn,
	loongarch@...ts.linux.dev
Subject: [PATCH AUTOSEL 6.6 11/23] LoongArch/irq: Use seq_put_decimal_ull_width() for decimal values

From: David Wang <00107082@....com>

[ 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@....com>
Signed-off-by: Huacai Chen <chenhuacai@...ngson.cn>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 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