[v1] replace call_rcu by kfree_rcu for simple kmem_cache_free callback

[PATCH 11/17] posix-timers: replace call_rcu by kfree_rcu for simple kmem_cache_free callback

Posted by Julia Lawall 1 month, 2 weeks ago

Since SLOB was removed and since
commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
it is not necessary to use call_rcu when the callback only performs
kmem_cache_free. Use kfree_rcu() directly.

The changes were made using Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>

---
 kernel/time/posix-timers.c |    9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 4576aaed13b2..fc40dacabe78 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -413,18 +413,11 @@ static struct k_itimer * alloc_posix_timer(void)
 	return tmr;
 }
 
-static void k_itimer_rcu_free(struct rcu_head *head)
-{
-	struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
-
-	kmem_cache_free(posix_timers_cache, tmr);
-}
-
 static void posix_timer_free(struct k_itimer *tmr)
 {
 	put_pid(tmr->it_pid);
 	sigqueue_free(tmr->sigq);
-	call_rcu(&tmr->rcu, k_itimer_rcu_free);
+	kfree_rcu(tmr, rcu);
 }
 
 static void posix_timer_unhash_and_free(struct k_itimer *tmr)

Re: [PATCH 11/17] posix-timers: replace call_rcu by kfree_rcu for simple kmem_cache_free callback

Posted by Uladzislau Rezki 1 month, 1 week ago

On Sun, Oct 13, 2024 at 10:16:58PM +0200, Julia Lawall wrote:
> Since SLOB was removed and since
> commit 6c6c47b063b5 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
> it is not necessary to use call_rcu when the callback only performs
> kmem_cache_free. Use kfree_rcu() directly.
> 
> The changes were made using Coccinelle.
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
> 
> ---
>  kernel/time/posix-timers.c |    9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)
> 
> diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
> index 4576aaed13b2..fc40dacabe78 100644
> --- a/kernel/time/posix-timers.c
> +++ b/kernel/time/posix-timers.c
> @@ -413,18 +413,11 @@ static struct k_itimer * alloc_posix_timer(void)
>  	return tmr;
>  }
>  
> -static void k_itimer_rcu_free(struct rcu_head *head)
> -{
> -	struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
> -
> -	kmem_cache_free(posix_timers_cache, tmr);
> -}
> -
>  static void posix_timer_free(struct k_itimer *tmr)
>  {
>  	put_pid(tmr->it_pid);
>  	sigqueue_free(tmr->sigq);
> -	call_rcu(&tmr->rcu, k_itimer_rcu_free);
> +	kfree_rcu(tmr, rcu);
>  }
>  
>  static void posix_timer_unhash_and_free(struct k_itimer *tmr)
> 
> 
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

--
Uladzislau Rezki

[tip: timers/core] posix-timers: Replace call_rcu() by kfree_rcu() for simple kmem_cache_free() callback

Posted by tip-bot2 for Julia Lawall 1 month ago

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     2e529e637cef39057d9cf199a1ecb915d97ffcd9
Gitweb:        https://git.kernel.org/tip/2e529e637cef39057d9cf199a1ecb915d97ffcd9
Author:        Julia Lawall <Julia.Lawall@inria.fr>
AuthorDate:    Sun, 13 Oct 2024 22:16:58 +02:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Thu, 24 Oct 2024 11:22:54 +02:00

posix-timers: Replace call_rcu() by kfree_rcu() for simple kmem_cache_free() callback

Since SLOB was removed and since commit 6c6c47b063b5 ("mm, slab: call
kvfree_rcu_barrier() from kmem_cache_destroy()"), it is not longer
necessary to use call_rcu() when the callback only performs
kmem_cache_free(). Use kfree_rcu() directly.

The changes were made using Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Link: https://lore.kernel.org/all/20241013201704.49576-12-Julia.Lawall@inria.fr
---
 kernel/time/posix-timers.c |  9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 4576aae..fc40dac 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -413,18 +413,11 @@ static struct k_itimer * alloc_posix_timer(void)
 	return tmr;
 }
 
-static void k_itimer_rcu_free(struct rcu_head *head)
-{
-	struct k_itimer *tmr = container_of(head, struct k_itimer, rcu);
-
-	kmem_cache_free(posix_timers_cache, tmr);
-}
-
 static void posix_timer_free(struct k_itimer *tmr)
 {
 	put_pid(tmr->it_pid);
 	sigqueue_free(tmr->sigq);
-	call_rcu(&tmr->rcu, k_itimer_rcu_free);
+	kfree_rcu(tmr, rcu);
 }
 
 static void posix_timer_unhash_and_free(struct k_itimer *tmr)