[PATCH -mm1] Remove useless calls to INIT_RCU_HEAD in the idr code (was Scalability requirements for sysv ipc - v3)

[PATCH -mm1] Remove useless calls to INIT_RCU_HEAD in the idr code (was Scalability requirements for sysv ipc - v3)

[Nadia.Derbey]

[-- Attachment #1: remove_useless_init_rcu_head_from_idr_code.patch --]
[-- Type: text/plain, Size: 1220 bytes --]

Since I didn't get any answer yesterday, (see http://lkml.org/lkml/2008/6/2/20)
here's the patch after Paul's review.


Regards,
Nadia

[ PATCH 01/01 ]

This is a trivial patch that removes unneeded calls to INIT_RCU_HEAD() in the
idr api code.

This patch applies to 2.6.26-rc2-mm1.

Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>

---
 lib/idr.c |    3 ---
 1 file changed, 3 deletions(-)

Index: linux-2.6.26-rc2-mm1/lib/idr.c
===================================================================
--- linux-2.6.26-rc2-mm1.orig/lib/idr.c	2008-05-29 13:09:01.000000000 +0200
+++ linux-2.6.26-rc2-mm1/lib/idr.c	2008-06-02 09:32:46.000000000 +0200
@@ -185,7 +185,6 @@ static int sub_alloc(struct idr *idp, in
 			new = get_from_free_list(idp);
 			if (!new)
 				return -1;
-			INIT_RCU_HEAD(&new->rcu_head);
 			rcu_assign_pointer(p->ary[m], new);
 			p->count++;
 		}
@@ -211,7 +210,6 @@ build_up:
 	if (unlikely(!p)) {
 		if (!(p = get_from_free_list(idp)))
 			return -1;
-		INIT_RCU_HEAD(&p->rcu_head);
 		layers = 1;
 	}
 	/*
@@ -239,7 +237,6 @@ build_up:
 		}
 		new->ary[0] = p;
 		new->count = 1;
-		INIT_RCU_HEAD(&new->rcu_head);
 		if (p->bitmap == IDR_FULL)
 			__set_bit(0, &new->bitmap);
 		p = new;

--

Re: [PATCH -mm1] Remove useless calls to INIT_RCU_HEAD in the idr code (was Scalability requirements for sysv ipc - v3)

[Paul E. McKenney]

On Tue, Jun 03, 2008 at 08:56:34AM +0200, Nadia.Derbey@bull.net wrote:
> Since I didn't get any answer yesterday, (see http://lkml.org/lkml/2008/6/2/20)
> here's the patch after Paul's review.
> 
> 
> Regards,
> Nadia
> 
> [ PATCH 01/01 ]
> 
> This is a trivial patch that removes unneeded calls to INIT_RCU_HEAD() in the
> idr api code.
> 
> This patch applies to 2.6.26-rc2-mm1.

Looks good to me!

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

> Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net>
> 
> ---
>  lib/idr.c |    3 ---
>  1 file changed, 3 deletions(-)
> 
> Index: linux-2.6.26-rc2-mm1/lib/idr.c
> ===================================================================
> --- linux-2.6.26-rc2-mm1.orig/lib/idr.c	2008-05-29 13:09:01.000000000 +0200
> +++ linux-2.6.26-rc2-mm1/lib/idr.c	2008-06-02 09:32:46.000000000 +0200
> @@ -185,7 +185,6 @@ static int sub_alloc(struct idr *idp, in
>  			new = get_from_free_list(idp);
>  			if (!new)
>  				return -1;
> -			INIT_RCU_HEAD(&new->rcu_head);
>  			rcu_assign_pointer(p->ary[m], new);
>  			p->count++;
>  		}
> @@ -211,7 +210,6 @@ build_up:
>  	if (unlikely(!p)) {
>  		if (!(p = get_from_free_list(idp)))
>  			return -1;
> -		INIT_RCU_HEAD(&p->rcu_head);
>  		layers = 1;
>  	}
>  	/*
> @@ -239,7 +237,6 @@ build_up:
>  		}
>  		new->ary[0] = p;
>  		new->count = 1;
> -		INIT_RCU_HEAD(&new->rcu_head);
>  		if (p->bitmap == IDR_FULL)
>  			__set_bit(0, &new->bitmap);
>  		p = new;
> 
> --