Re: [PATCH 02/12] sched_ext: Make several ext.c helpers available outside ext.c

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Unconditional definition of `scx_sched_all` lacks a prototype when `CONFIG_EXT_SUB_SCHED` is disabled, causing a build warning.
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--- Patch [2]: [PATCH 02/12] sched_ext: Make several ext.c helpers available outside ext.c ---
commit 2fbc86143bb66368e04e606cb09e7ffe2b987b3d
Author: Tejun Heo <tj@kernel.org>

sched_ext: Make several ext.c helpers available outside ext.c

This commit exposes several helper functions and the scx_sched_all list
by removing their static keywords and adding declarations in internal.h.
This allows them to be utilized outside of ext.c.

> --- a/kernel/sched/ext/ext.c
> +++ b/kernel/sched/ext/ext.c
> @@ -38,7 +38,7 @@ struct scx_sched __rcu *scx_root;
>   * All scheds, writers must hold both scx_enable_mutex and scx_sched_lock.
>   * Readers can hold either or rcu_read_lock().
>   */
> -static LIST_HEAD(scx_sched_all);
> +LIST_HEAD(scx_sched_all);

[ ... ]

> --- a/kernel/sched/ext/internal.h
> +++ b/kernel/sched/ext/internal.h
> @@ -2014,6 +2021,7 @@ extern bool scx_cgroup_enabled;
>  #ifdef CONFIG_EXT_SUB_SCHED
>  extern const struct rhashtable_params scx_sched_hash_params;
>  extern struct rhashtable scx_sched_hash;
> +extern struct list_head scx_sched_all;

[Severity: Low]
Will this trigger a missing prototype warning when CONFIG_EXT_SUB_SCHED is
disabled?

Because scx_sched_all is defined unconditionally in ext.c, building the
kernel without CONFIG_EXT_SUB_SCHED hides this extern declaration in
internal.h from the compiler. 

Should this declaration be moved outside of the ifdef block to prevent
compiler or sparse warnings?

>  extern struct scx_sched *scx_enabling_sub_sched;
>  #endif

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Sashiko AI review · https://sashiko.dev/#/patchset/20260801085150.2697653-1-tj@kernel.org?part=2