Commit d2a5f10b authored by David Wang's avatar David Wang Committed by John Paul Adrian Glaubitz
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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: default avatarDavid Wang <00107082@163.com>
Reviewed-by: default avatarJohn Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: default avatarJohn Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
parent 40384c84

arch/sh/kernel/irq.c

+2 −2
Original line number Diff line number Diff line
@@ -45,7 +45,7 @@ int arch_show_interrupts(struct seq_file *p, int prec) 


	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));