Re: [PATCH 3/6] sched: Report the different kinds of imbalances in /proc/schedstat

[Peter Zijlstra]

On Wed, Dec 18, 2024 at 04:36:26AM +0000, Swapnil Sapkal wrote:

> +static void update_lb_imbalance_stat(struct lb_env *env, struct sched_domain *sd,
> +				     enum cpu_idle_type idle)
> +{
> +	switch (env->migration_type) {
> +	case migrate_load:
> +		schedstat_add(sd->lb_imbalance_load[idle], env->imbalance);
> +		break;
> +	case migrate_util:
> +		schedstat_add(sd->lb_imbalance_util[idle], env->imbalance);
> +		break;
> +	case migrate_task:
> +		schedstat_add(sd->lb_imbalance_task[idle], env->imbalance);
> +		break;
> +	case migrate_misfit:
> +		schedstat_add(sd->lb_imbalance_misfit[idle], env->imbalance);
> +		break;
> +	}
> +}


Can you please write that like:

	if (!schedstat_enabled())
		return;

	switch () {
	case ...
		__schedstat_add();
	}

It makes no sense to have 4 copies of schedstat_enabled() inside the
switch statement -- esp. since afaik the compilers aren't able to CSE
static keys :/