Re: + mm-slab_common-commonize-slab-merge-logic.patch added to -mm tree

[Joonsoo Kim]

On Fri, Sep 19, 2014 at 03:37:45PM -0700, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
> 
> The patch titled
>      Subject: mm/slab_common: commonize slab merge logic
> has been added to the -mm tree.  Its filename is
>      mm-slab_common-commonize-slab-merge-logic.patch
> 
> This patch should soon appear at
>     http://ozlabs.org/~akpm/mmots/broken-out/mm-slab_common-commonize-slab-merge-logic.patch
> and later at
>     http://ozlabs.org/~akpm/mmotm/broken-out/mm-slab_common-commonize-slab-merge-logic.patch
> 
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> 
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
> 
> The -mm tree is included into linux-next and is updated
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> 
> ------------------------------------------------------
> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Subject: mm/slab_common: commonize slab merge logic
> 
> Slab merge is good feature to reduce fragmentation.  Now, it is only
> applied to SLUB, but, it would be good to apply it to SLAB.  This patch is
> preparation step to apply slab merge to SLAB by commonizing slab merge
> logic.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: Christoph Lameter <cl@xxxxxxxxx>
> Cc: Pekka Enberg <penberg@xxxxxxxxxx>
> Cc: David Rientjes <rientjes@xxxxxxxxxx>
> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> ---
> 
>  Documentation/kernel-parameters.txt |   14 ++--
>  mm/slab.h                           |   15 ++++
>  mm/slab_common.c                    |   91 ++++++++++++++++++++++++++
>  mm/slub.c                           |   91 --------------------------
>  4 files changed, 117 insertions(+), 94 deletions(-)
> 
> diff -puN Documentation/kernel-parameters.txt~mm-slab_common-commonize-slab-merge-logic Documentation/kernel-parameters.txt
> --- a/Documentation/kernel-parameters.txt~mm-slab_common-commonize-slab-merge-logic
> +++ a/Documentation/kernel-parameters.txt
> @@ -3140,6 +3140,13 @@ bytes respectively. Such letter suffixes
>  
>  	slram=		[HW,MTD]
>  
> +	slab_nomerge	[MM]
> +			Disable merging of slabs with similar size. May be
> +			necessary if there is some reason to distinguish
> +			allocs to different slabs. Debug options disable
> +			merging on their own.
> +			For more information see Documentation/vm/slub.txt.
> +
>  	slab_max_order=	[MM, SLAB]
>  			Determines the maximum allowed order for slabs.
>  			A high setting may cause OOMs due to memory
> @@ -3175,11 +3182,8 @@ bytes respectively. Such letter suffixes
>  			For more information see Documentation/vm/slub.txt.
>  
>  	slub_nomerge	[MM, SLUB]
> -			Disable merging of slabs with similar size. May be
> -			necessary if there is some reason to distinguish
> -			allocs to different slabs. Debug options disable
> -			merging on their own.
> -			For more information see Documentation/vm/slub.txt.
> +			Same with slab_nomerge. This is supported for legacy.
> +			See slab_nomerge for more information.
>  
>  	smart2=		[HW]
>  			Format: <io1>[,<io2>[,...,<io8>]]
> diff -puN mm/slab.h~mm-slab_common-commonize-slab-merge-logic mm/slab.h
> --- a/mm/slab.h~mm-slab_common-commonize-slab-merge-logic
> +++ a/mm/slab.h
> @@ -88,15 +88,30 @@ extern void create_boot_cache(struct kme
>  			size_t size, unsigned long flags);
>  
>  struct mem_cgroup;
> +
> +int slab_unmergeable(struct kmem_cache *s);
> +struct kmem_cache *find_mergeable(size_t size, size_t align,
> +		unsigned long flags, const char *name, void (*ctor)(void *));
>  #ifdef CONFIG_SLUB
>  struct kmem_cache *
>  __kmem_cache_alias(const char *name, size_t size, size_t align,
>  		   unsigned long flags, void (*ctor)(void *));
> +
> +unsigned long kmem_cache_flags(unsigned long object_size,
> +	unsigned long flags, const char *name,
> +	void (*ctor)(void *));
>  #else
>  static inline struct kmem_cache *
>  __kmem_cache_alias(const char *name, size_t size, size_t align,
>  		   unsigned long flags, void (*ctor)(void *))
>  { return NULL; }
> +
> +static inline unsigned long kmem_cache_flags(unsigned long object_size,
> +	unsigned long flags, const char *name,
> +	void (*ctor)(void *))
> +{
> +	return flags;
> +}
>  #endif
>  
>  
> diff -puN mm/slab_common.c~mm-slab_common-commonize-slab-merge-logic mm/slab_common.c
> --- a/mm/slab_common.c~mm-slab_common-commonize-slab-merge-logic
> +++ a/mm/slab_common.c
> @@ -31,6 +31,34 @@ DEFINE_MUTEX(slab_mutex);
>  struct kmem_cache *kmem_cache;
>  
>  /*
> + * Set of flags that will prevent slab merging
> + */
> +#define SLAB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
> +		SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
> +		SLAB_FAILSLAB)
> +
> +#define SLAB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
> +		SLAB_CACHE_DMA | SLAB_NOTRACK)
> +
> +/*
> + * Merge control. If this is set then no merging of slab caches will occur.
> + * (Could be removed. This was introduced to pacify the merge skeptics.)
> + */
> +static int slab_nomerge;
> +
> +static int __init setup_slab_nomerge(char *str)
> +{
> +	slab_nomerge = 1;
> +	return 1;
> +}
> +
> +#ifdef CONFIG_SLUB
> +__setup("slub_nomerge", setup_slab_nomerge);
> +#endif
> +
> +__setup("slab_nomerge", setup_slab_nomerge);

Hello, Andrew.

This patch has build failure problem if CONFIG_SLUB.
Detailed information and fix is in following patch.

Thanks.


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