Re: [PATCH 02/10] sched/balancing: Remove reliance on 'enum cpu_idle_type' ordering when iterating [CPU_MAX_IDLE_TYPES] arrays in show_schedstat()

From: Vincent Guittot
Date: Fri Mar 08 2024 - 08:27:22 EST


On Fri, 8 Mar 2024 at 11:59, Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> From: Shrikanth Hegde <sshegde@xxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxx>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Cc: Valentin Schneider <vschneid@xxxxxxxxxx>

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

> ---
> 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
>