Re: [PATCH -mmotm v2] mm: fix kmemcheck.c build errors

From: Randy Dunlap
Date: Sun Aug 31 2014 - 20:17:28 EST


On 08/31/14 17:13, Joonsoo Kim wrote:
> On Sun, Aug 31, 2014 at 04:33:12PM -0700, Randy Dunlap wrote:
>> On 08/31/14 07:48, Randy Dunlap wrote:
>>> On 08/31/14 04:36, Andrey Ryabinin wrote:
>>>> 2014-08-30 5:48 GMT+04:00 Randy Dunlap <rdunlap@xxxxxxxxxxxxx>:
>>>>> From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>>>>>
>>>>> Add header file to fix kmemcheck.c build errors:
>>>>>
>>>>> ../mm/kmemcheck.c:70:7: error: dereferencing pointer to incomplete type
>>>>> ../mm/kmemcheck.c:83:15: error: dereferencing pointer to incomplete type
>>>>> ../mm/kmemcheck.c:95:8: error: dereferencing pointer to incomplete type
>>>>> ../mm/kmemcheck.c:95:21: error: dereferencing pointer to incomplete type
>>>>>
>>>>> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>>>>> ---
>>>>> mm/kmemcheck.c | 1 +
>>>>> 1 file changed, 1 insertion(+)
>>>>>
>>>>> Index: mmotm-2014-0829-1515/mm/kmemcheck.c
>>>>> ===================================================================
>>>>> --- mmotm-2014-0829-1515.orig/mm/kmemcheck.c
>>>>> +++ mmotm-2014-0829-1515/mm/kmemcheck.c
>>>>> @@ -2,6 +2,7 @@
>>>>> #include <linux/mm_types.h>
>>>>> #include <linux/mm.h>
>>>>> #include <linux/slab.h>
>>>>> +#include <linux/slab_def.h>
>>>>
>>>> This will work only for CONFIG_SLAB=y. struct kmem_cache definition
>>>> was moved to internal header [*],
>>>> so you need to include it here:
>>>> #include "slab.h"
>>>>
>>>> [*] http://ozlabs.org/~akpm/mmotm/broken-out/mm-slab_common-move-kmem_cache-definition-to-internal-header.patch
>>>
>>> Thanks. That makes sense. [testing] mm/kmemcheck.c still has a build error:
>>>
>>> In file included from ../mm/kmemcheck.c:5:0:
>>> ../mm/slab.h: In function 'cache_from_obj':
>>> ../mm/slab.h:283:2: error: implicit declaration of function 'memcg_kmem_enabled' [-Werror=implicit-function-declaration]
>>>
>>
>> Naughty header file. It uses something from <linux/memcontrol.h> without
>> #including that header file...
>
>
> Hello.
>
> Indeed...
> Thanks for catching this.
>
>>
>> Working patch is below.
>
> With your patch, build also failed if CONFIG_MEMCG_KMEM=y.
> Right fix is something like below.
>
> Thanks.
>
> --------->8----------
> diff --git a/mm/kmemcheck.c b/mm/kmemcheck.c
> index fd814fd..cab58bb 100644
> --- a/mm/kmemcheck.c
> +++ b/mm/kmemcheck.c
> @@ -2,6 +2,7 @@
> #include <linux/mm_types.h>
> #include <linux/mm.h>
> #include <linux/slab.h>
> +#include "slab.h"
> #include <linux/kmemcheck.h>
>
> void kmemcheck_alloc_shadow(struct page *page, int order, gfp_t flags, int node)
> diff --git a/mm/slab.h b/mm/slab.h
> index 13845d0..963a3f8 100644
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -37,6 +37,8 @@ struct kmem_cache {
> #include <linux/slub_def.h>
> #endif
>
> +#include <linux/memcontrol.h>
> +
> /*
> * State of the slab allocator.
> *
> --

Um, yeah, looks equivalent to what I sent as v2.

Thanks.

--
~Randy
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