Re: [PATCH 2/5] sched: dynamic: Simplify {cond,might}_resched()

[Shrikanth Hegde <sshegde@linux.ibm.com>]

On 7/3/26 7:03 PM, Mark Rutland wrote:
> PREEMPT_DYNAMIC is now limited to the FULL and LAZY preemption models.
> In either model, both cond_resched() and might_resched() are always
> disabled and do nothing.
> 
> Remove the unnecessary code for these when PREEMPT_DYNAMIC is selected.
> 
> Signed-off-by: Mark Rutland <mark.rutland@arm.com>
> Cc: Frederic Weisbecker <frederic@kernel.org>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: John Stultz <jstultz@google.com>
> Cc: Juri Lelli <juri.lelli@redhat.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Valentin Schneider <vschneid@redhat.com>
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> ---
>   include/linux/kernel.h | 20 -------------------
>   include/linux/sched.h  | 31 +++--------------------------
>   kernel/sched/core.c    | 44 +-----------------------------------------
>   3 files changed, 4 insertions(+), 91 deletions(-)
> 
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index e5570a16cbb1a..533ee1e6e1cb7 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -43,30 +43,10 @@ struct completion;
>   struct user;
>   
>   #ifdef CONFIG_PREEMPT_VOLUNTARY_BUILD

Would it make sense to move this block under CONFIG_PREEMPT_VOLUNTARY_BUILD
to include/linux/sched.h so they all in one header?

this builds. I meant something like below.
---

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 533ee1e6e1cb..49495eb754d5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -42,13 +42,6 @@
  struct completion;
  struct user;
  
-#ifdef CONFIG_PREEMPT_VOLUNTARY_BUILD
-extern int __cond_resched(void);
-# define might_resched() __cond_resched()
-#else
-# define might_resched() do { } while (0)
-#endif /* CONFIG_PREEMPT_* */
-
  #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
  extern void __might_resched(const char *file, int line, unsigned int offsets);
  extern void __might_sleep(const char *file, int line);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index db6e757e83c7..ddc9aae96e55 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -2112,6 +2112,13 @@ static inline void set_need_resched_current(void)
         set_preempt_need_resched();
  }
  
+#ifdef CONFIG_PREEMPT_VOLUNTARY_BUILD
+extern int __cond_resched(void);
+# define might_resched() __cond_resched()
+#else
+# define might_resched() do { } while (0)
+#endif /* CONFIG_PREEMPT_* */
+
  /*
   * cond_resched() and cond_resched_lock(): latency reduction via
   * explicit rescheduling in places that are safe. The return


> -
>   extern int __cond_resched(void);
>   # define might_resched() __cond_resched()
> -
> -#elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_CALL)
> -
> -extern int __cond_resched(void);
> -
> -DECLARE_STATIC_CALL(might_resched, __cond_resched);
> -
> -static __always_inline void might_resched(void)
> -{
> -	static_call_mod(might_resched)();
> -}
> -
> -#elif defined(CONFIG_PREEMPT_DYNAMIC) && defined(CONFIG_HAVE_PREEMPT_DYNAMIC_KEY)
> -
> -extern int dynamic_might_resched(void);
> -# define might_resched() dynamic_might_resched()
> -
>   #else
> -
>   # define might_resched() do { } while (0)
> -
>   #endif /* CONFIG_PREEMPT_* */
>   
>   #ifdef CONFIG_DEBUG_ATOMIC_SLEEP


Other than that, rest looks good to me.

Reviewed-by: Shrikanth Hegde <sshegde@linux.ibm.com>