2007-05-11 15:35:30

by Bernhard Walle

[permalink] [raw]
Subject: [PATCH] Fix section mismatch

This patch fixes following compile warning:

--------- >8 --------
WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text
between 'kmem_cache_create' (at offset 0x2167b) and 'drain_alien_cache'

WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text
between 'kmem_cache_create' (at offset 0x216c1) and 'drain_alien_cache'
--------- 8< --------

set_up_list3s() can be called from setup_cpu_cache() [mm/slab.c] which is not
an init function.


Signed-off-by: Bernhard Walle <[email protected]>

---
mm/slab.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/slab.c
+++ b/mm/slab.c
@@ -305,7 +305,7 @@ struct kmem_list3 {
* Need this for bootstrapping a per node allocator.
*/
#define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
-struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
+struct kmem_list3 initkmem_list3[NUM_INIT_LISTS];
#define CACHE_CACHE 0
#define SIZE_AC 1
#define SIZE_L3 (1 + MAX_NUMNODES)
@@ -1960,7 +1960,7 @@ static void slab_destroy(struct kmem_cac
* For setting up all the kmem_list3s for cache whose buffer_size is same as
* size of kmem_list3.
*/
-static void __init set_up_list3s(struct kmem_cache *cachep, int index)
+static void set_up_list3s(struct kmem_cache *cachep, int index)
{
int node;


2007-05-11 17:57:49

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH] Fix section mismatch

On Fri, 11 May 2007 17:35:22 +0200
Bernhard Walle <[email protected]> wrote:

> This patch fixes following compile warning:
>
> --------- >8 --------
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text
> between 'kmem_cache_create' (at offset 0x2167b) and 'drain_alien_cache'
>
> WARNING: mm/built-in.o - Section mismatch: reference to .init.text: from .text
> between 'kmem_cache_create' (at offset 0x216c1) and 'drain_alien_cache'
> --------- 8< --------
>
> set_up_list3s() can be called from setup_cpu_cache() [mm/slab.c] which is not
> an init function.
>
>

Yes. This warning is a false positive. See

static int setup_cpu_cache(struct kmem_cache *cachep)
{
if (g_cpucache_up == FULL)
return enable_cpucache(cachep);

if (g_cpucache_up == NONE) {
...
set_up_list3s(cachep, SIZE_AC);

The g_cpucache_up==NONE state only exists before we have run free_initmem().

There is a similar false-positive down in acpi somewhere.

I think Sam is working on a scheme whereby we can add annotation to quash
the warnings in cases such as this.


>
> ---
> mm/slab.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -305,7 +305,7 @@ struct kmem_list3 {
> * Need this for bootstrapping a per node allocator.
> */
> #define NUM_INIT_LISTS (2 * MAX_NUMNODES + 1)
> -struct kmem_list3 __initdata initkmem_list3[NUM_INIT_LISTS];
> +struct kmem_list3 initkmem_list3[NUM_INIT_LISTS];
> #define CACHE_CACHE 0
> #define SIZE_AC 1
> #define SIZE_L3 (1 + MAX_NUMNODES)
> @@ -1960,7 +1960,7 @@ static void slab_destroy(struct kmem_cac
> * For setting up all the kmem_list3s for cache whose buffer_size is same as
> * size of kmem_list3.
> */
> -static void __init set_up_list3s(struct kmem_cache *cachep, int index)
> +static void set_up_list3s(struct kmem_cache *cachep, int index)
> {
> int node;

That'll shut it up, but we'll use more memory at runtime.