[PATCH] mm: remove all rcu head initializations

[PATCH] mm: remove all rcu head initializations

[Paul E. McKenney]

Hello!

Would you guys like to carry this patch, or should I push it up
-tip?  If I don't hear otherwise from you, I will push it up -tip.
The INIT_RCU_HEAD() primitive is going away in favor of debugobjects.

							Thanx, Paul

------------------------------------------------------------------------

mm: remove all rcu head initializations

Remove all rcu head inits. We don't care about the RCU head state before passing
it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
keep track of objects on stack.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 707d0dc..f03d8d6 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -663,7 +663,6 @@ int bdi_init(struct backing_dev_info *bdi)
 	bdi->max_ratio = 100;
 	bdi->max_prop_frac = PROP_FRAC_BASE;
 	spin_lock_init(&bdi->wb_lock);
-	INIT_RCU_HEAD(&bdi->rcu_head);
 	INIT_LIST_HEAD(&bdi->bdi_list);
 	INIT_LIST_HEAD(&bdi->wb_list);
 	INIT_LIST_HEAD(&bdi->work_list);
diff --git a/mm/slob.c b/mm/slob.c
index 837ebd6..6de238d 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -647,7 +647,6 @@ void kmem_cache_free(struct kmem_cache *c, void *b)
 	if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
 		struct slob_rcu *slob_rcu;
 		slob_rcu = b + (c->size - sizeof(struct slob_rcu));
-		INIT_RCU_HEAD(&slob_rcu->head);
 		slob_rcu->size = c->size;
 		call_rcu(&slob_rcu->head, kmem_rcu_free);
 	} else {

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

Re: [PATCH] mm: remove all rcu head initializations

[KOSAKI Motohiro]

Hi

> Hello!
> 
> Would you guys like to carry this patch, or should I push it up
> -tip?  If I don't hear otherwise from you, I will push it up -tip.
> The INIT_RCU_HEAD() primitive is going away in favor of debugobjects.
> 
> 							Thanx, Paul

Personally, I don't think this patch can make major conflict. So, I guess
-tip is best.

Thanks.


> 
> ------------------------------------------------------------------------
> 
> mm: remove all rcu head initializations
> 
> Remove all rcu head inits. We don't care about the RCU head state before passing
> it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
> keep track of objects on stack.
> 
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> Cc: Christoph Lameter <cl@linux-foundation.org>
> Cc: Pekka Enberg <penberg@cs.helsinki.fi>
> Cc: Matt Mackall <mpm@selenic.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> 
> diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> index 707d0dc..f03d8d6 100644
> --- a/mm/backing-dev.c
> +++ b/mm/backing-dev.c
> @@ -663,7 +663,6 @@ int bdi_init(struct backing_dev_info *bdi)
>  	bdi->max_ratio = 100;
>  	bdi->max_prop_frac = PROP_FRAC_BASE;
>  	spin_lock_init(&bdi->wb_lock);
> -	INIT_RCU_HEAD(&bdi->rcu_head);
>  	INIT_LIST_HEAD(&bdi->bdi_list);
>  	INIT_LIST_HEAD(&bdi->wb_list);
>  	INIT_LIST_HEAD(&bdi->work_list);
> diff --git a/mm/slob.c b/mm/slob.c
> index 837ebd6..6de238d 100644
> --- a/mm/slob.c
> +++ b/mm/slob.c
> @@ -647,7 +647,6 @@ void kmem_cache_free(struct kmem_cache *c, void *b)
>  	if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
>  		struct slob_rcu *slob_rcu;
>  		slob_rcu = b + (c->size - sizeof(struct slob_rcu));
> -		INIT_RCU_HEAD(&slob_rcu->head);
>  		slob_rcu->size = c->size;
>  		call_rcu(&slob_rcu->head, kmem_rcu_free);
>  	} else {
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>



--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>