Re: [PATCH] sched: core: Optimize the structure of 'tg_cfs_schedulable_down' function

From: Benjamin Segall
Date: Mon Mar 20 2023 - 18:48:44 EST


Li kunyu <kunyu@xxxxxxxxxxxx> writes:

> Optimize if branches and define in the branch statement
> block parent_quota variable.

It's not an optimization; it is arguably a slight style improvement.

>
> Signed-off-by: Li kunyu <kunyu@xxxxxxxxxxxx>
> ---
> kernel/sched/core.c | 9 +++------
> 1 file changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 488655f2319f..7e8535d2e36d 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -10915,15 +10915,12 @@ static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
> {
> struct cfs_schedulable_data *d = data;
> struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
> - s64 quota = 0, parent_quota = -1;
> + s64 quota = RUNTIME_INF;
>
> - if (!tg->parent) {
> - quota = RUNTIME_INF;
> - } else {
> + if (tg->parent) {
> struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth;
> -
> + s64 parent_quota = parent_b->hierarchical_quota;
> quota = normalize_cfs_quota(tg, d);
> - parent_quota = parent_b->hierarchical_quota;
>
> /*
> * Ensure max(child_quota) <= parent_quota. On cgroup2,