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From: Vincent Guittot <vincent.guittot@linaro.org>
Date: Fri, 8 Mar 2024 14:26:16 +0100
Message-ID: <CAKfTPtAFQZHxzgju2As6qAmi+VxWk1H_5L44UX+XcbqYHSneCQ@mail.gmail.com>
Subject: Re: [PATCH 02/10] sched/balancing: Remove reliance on 'enum
 cpu_idle_type' ordering when iterating [CPU_MAX_IDLE_TYPES] arrays in show_schedstat()
To: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org, Dietmar Eggemann <dietmar.eggemann@arm.com>, 
	Linus Torvalds <torvalds@linux-foundation.org>, Peter Zijlstra <peterz@infradead.org>, 
	Shrikanth Hegde <sshegde@linux.ibm.com>, Valentin Schneider <vschneid@redhat.com>
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On Fri, 8 Mar 2024 at 11:59, Ingo Molnar <mingo@kernel.org> wrote:
>
> From: Shrikanth Hegde <sshegde@linux.ibm.com>
>
> show_schedstat() output breaks and doesn't print all entries
> if the ordering of the definitions in 'enum cpu_idle_type' is changed,
> because show_schedstat() assumes that 'CPU_IDLE' is 0.
>
> Fix it before we change the definition order & values.
>
> [ mingo: Added changelog. ]
>
> Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Valentin Schneider <vschneid@redhat.com>

Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>

> ---
>  kernel/sched/stats.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
> index 857f837f52cb..85277953cc72 100644
> --- a/kernel/sched/stats.c
> +++ b/kernel/sched/stats.c
> @@ -150,8 +150,7 @@ static int show_schedstat(struct seq_file *seq, void *v)
>
>                         seq_printf(seq, "domain%d %*pb", dcount++,
>                                    cpumask_pr_args(sched_domain_span(sd)));
> -                       for (itype = CPU_IDLE; itype < CPU_MAX_IDLE_TYPES;
> -                                       itype++) {
> +                       for (itype = 0; itype < CPU_MAX_IDLE_TYPES; itype++) {
>                                 seq_printf(seq, " %u %u %u %u %u %u %u %u",
>                                     sd->lb_count[itype],
>                                     sd->lb_balanced[itype],
> --
> 2.40.1
>