sh: irq: Use seq_put_decimal_ull_width() for decimal values

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

Signed-off-by: David Wang <[email protected]>
Reviewed-by: John Paul Adrian Glaubitz <[email protected]>
Signed-off-by: John Paul Adrian Glaubitz <[email protected]>

Author: zq-david-wang

arch/sh/kernel/irq.c

@@ -43,9 +43,9 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 {
 	int j;
 
-	seq_printf(p, "%*s: ", prec, "NMI");
+	seq_printf(p, "%*s:", prec, "NMI");
 	for_each_online_cpu(j)
-		seq_printf(p, "%10u ", per_cpu(irq_stat.__nmi_count, j));
+		seq_put_decimal_ull_width(p, " ", per_cpu(irq_stat.__nmi_count, j), 10);
 	seq_printf(p, "  Non-maskable interrupts\n");
 
 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));