2020-09-16 03:46:49

by Xu Wang

Subject: [PATCH] stats: Replace seq_printf with seq_puts

seq_puts is a lot cheaper than seq_printf, so use that to print
literal strings.

Signed-off-by: Xu Wang <[email protected]>
---
kernel/sched/stats.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index 750fb3c67eed..0818fe03407a 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -37,7 +37,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
rq->rq_cpu_time,
rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);

- seq_printf(seq, "\n");
+ seq_putc(seq, '\n');

#ifdef CONFIG_SMP
/* domain-specific stats */
--
2.17.1

2020-09-16 08:14:29

by Peter Zijlstra

Subject: Re: [PATCH] stats: Replace seq_printf with seq_puts

On Wed, Sep 16, 2020 at 03:44:15AM +0000, Xu Wang wrote:
> seq_puts is a lot cheaper than seq_printf, so use that to print
> literal strings.

performance is not a consideration here.

> Signed-off-by: Xu Wang <[email protected]>
> ---
> kernel/sched/stats.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
> index 750fb3c67eed..0818fe03407a 100644
> --- a/kernel/sched/stats.c
> +++ b/kernel/sched/stats.c
> @@ -37,7 +37,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
> rq->rq_cpu_time,
> rq->rq_sched_info.run_delay, rq->rq_sched_info.pcount);
>
> - seq_printf(seq, "\n");
> + seq_putc(seq, '\n');

And yet, the changelog says seq_put*s*().

>
> #ifdef CONFIG_SMP
> /* domain-specific stats */
> --
> 2.17.1
>