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From: JoonSoo Kim <js1304@gmail.com>
To: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>,
	Glauber Costa <glommer@parallels.com>,
	linux-mm@kvack.org, David Rientjes <rientjes@google.com>,
	elezegarcia@gmail.com
Subject: Re: CK2 [02/15] create common functions for boot slab creation
Date: Sun, 21 Oct 2012 00:57:49 +0900	[thread overview]
Message-ID: <CAAmzW4Mbovj8f5bQ4hFKLn8xExjE4qTYuHWSjnWW2P1ToA1qGg@mail.gmail.com> (raw)
In-Reply-To: <0000013a796a7912-d1ca62fc-fe3a-460a-853e-85e5535c1e60-000000@email.amazonses.com>

Hello, Christoph.

2012/10/19 Christoph Lameter <cl@linux.com>:
> Use a special function to create kmalloc caches and use that function in
> SLAB and SLUB.
>
> V1->V2:
>         Do check for slasb state in slub's __kmem_cache_create to avoid
>         unlocking a lock that was not taken
>
> Reviewed-by: Glauber Costa <glommer@parallels.com>
> Signed-off-by: Christoph Lameter <cl@linux.com>
> ---
>  mm/slab.c        |   48 ++++++++++++++----------------------------------
>  mm/slab.h        |    5 +++++
>  mm/slab_common.c |   32 ++++++++++++++++++++++++++++++++
>  mm/slub.c        |   36 +++---------------------------------
>  4 files changed, 54 insertions(+), 67 deletions(-)
>
> Index: linux/mm/slab.c
> ===================================================================
> --- linux.orig/mm/slab.c        2012-10-19 09:12:41.934366687 -0500
> +++ linux/mm/slab.c     2012-10-19 09:12:44.158404719 -0500
> @@ -1679,23 +1679,13 @@ void __init kmem_cache_init(void)
>          * bug.
>          */
>
> -       sizes[INDEX_AC].cs_cachep = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> -       sizes[INDEX_AC].cs_cachep->name = names[INDEX_AC].name;
> -       sizes[INDEX_AC].cs_cachep->size = sizes[INDEX_AC].cs_size;
> -       sizes[INDEX_AC].cs_cachep->object_size = sizes[INDEX_AC].cs_size;
> -       sizes[INDEX_AC].cs_cachep->align = ARCH_KMALLOC_MINALIGN;
> -       __kmem_cache_create(sizes[INDEX_AC].cs_cachep, ARCH_KMALLOC_FLAGS|SLAB_PANIC);
> -       list_add(&sizes[INDEX_AC].cs_cachep->list, &slab_caches);
> +       sizes[INDEX_AC].cs_cachep = create_kmalloc_cache(names[INDEX_AC].name,
> +                                       sizes[INDEX_AC].cs_size, ARCH_KMALLOC_FLAGS);
>
> -       if (INDEX_AC != INDEX_L3) {
> -               sizes[INDEX_L3].cs_cachep = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> -               sizes[INDEX_L3].cs_cachep->name = names[INDEX_L3].name;
> -               sizes[INDEX_L3].cs_cachep->size = sizes[INDEX_L3].cs_size;
> -               sizes[INDEX_L3].cs_cachep->object_size = sizes[INDEX_L3].cs_size;
> -               sizes[INDEX_L3].cs_cachep->align = ARCH_KMALLOC_MINALIGN;
> -               __kmem_cache_create(sizes[INDEX_L3].cs_cachep, ARCH_KMALLOC_FLAGS|SLAB_PANIC);
> -               list_add(&sizes[INDEX_L3].cs_cachep->list, &slab_caches);
> -       }
> +       if (INDEX_AC != INDEX_L3)
> +               sizes[INDEX_L3].cs_cachep =
> +                       create_kmalloc_cache(names[INDEX_L3].name,
> +                               sizes[INDEX_L3].cs_size, ARCH_KMALLOC_FLAGS);
>
>         slab_early_init = 0;
>
> @@ -1707,24 +1697,14 @@ void __init kmem_cache_init(void)
>                  * Note for systems short on memory removing the alignment will
>                  * allow tighter packing of the smaller caches.
>                  */
> -               if (!sizes->cs_cachep) {
> -                       sizes->cs_cachep = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> -                       sizes->cs_cachep->name = names->name;
> -                       sizes->cs_cachep->size = sizes->cs_size;
> -                       sizes->cs_cachep->object_size = sizes->cs_size;
> -                       sizes->cs_cachep->align = ARCH_KMALLOC_MINALIGN;
> -                       __kmem_cache_create(sizes->cs_cachep, ARCH_KMALLOC_FLAGS|SLAB_PANIC);
> -                       list_add(&sizes->cs_cachep->list, &slab_caches);
> -               }
> +               if (!sizes->cs_cachep)
> +                       sizes->cs_cachep = create_kmalloc_cache(names->name,
> +                                       sizes->cs_size, ARCH_KMALLOC_FLAGS);
> +
>  #ifdef CONFIG_ZONE_DMA
> -               sizes->cs_dmacachep = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> -               sizes->cs_dmacachep->name = names->name_dma;
> -               sizes->cs_dmacachep->size = sizes->cs_size;
> -               sizes->cs_dmacachep->object_size = sizes->cs_size;
> -               sizes->cs_dmacachep->align = ARCH_KMALLOC_MINALIGN;
> -               __kmem_cache_create(sizes->cs_dmacachep,
> -                              ARCH_KMALLOC_FLAGS|SLAB_CACHE_DMA| SLAB_PANIC);
> -               list_add(&sizes->cs_dmacachep->list, &slab_caches);
> +               sizes->cs_dmacachep = create_kmalloc_cache(
> +                       names->name_dma, sizes->cs_size,
> +                       SLAB_CACHE_DMA|ARCH_KMALLOC_FLAGS);
>  #endif
>                 sizes++;
>                 names++;
> Index: linux/mm/slab.h
> ===================================================================
> --- linux.orig/mm/slab.h        2012-10-18 10:37:51.372631802 -0500
> +++ linux/mm/slab.h     2012-10-19 09:12:44.158404719 -0500
> @@ -35,6 +35,11 @@ extern struct kmem_cache *kmem_cache;
>  /* Functions provided by the slab allocators */
>  extern int __kmem_cache_create(struct kmem_cache *, unsigned long flags);
>
> +extern struct kmem_cache *create_kmalloc_cache(const char *name, size_t size,
> +                       unsigned long flags);
> +extern void create_boot_cache(struct kmem_cache *, const char *name,
> +                       size_t size, unsigned long flags);
> +
>  #ifdef CONFIG_SLUB
>  struct kmem_cache *__kmem_cache_alias(const char *name, size_t size,
>         size_t align, unsigned long flags, void (*ctor)(void *));
> Index: linux/mm/slab_common.c
> ===================================================================
> --- linux.orig/mm/slab_common.c 2012-10-18 10:37:51.392632144 -0500
> +++ linux/mm/slab_common.c      2012-10-19 09:12:44.158404719 -0500
> @@ -192,3 +192,39 @@ int slab_is_available(void)
>  {
>         return slab_state >= UP;
>  }
> +
> +#ifndef CONFIG_SLOB
> +/* Create a cache during boot when no slab services are available yet */
> +void __init create_boot_cache(struct kmem_cache *s, const char *name, size_t size,
> +               unsigned long flags)
> +{
> +       int err;
> +
> +       s->name = name;
> +       s->size = s->object_size = size;
> +       s->align = ARCH_KMALLOC_MINALIGN;
> +       err = __kmem_cache_create(s, flags);
> +
> +       if (err)
> +               panic("Creation of kmalloc slab %s size=%td failed. Reason %d\n",
> +                                       name, size, err);
> +
> +       list_add(&s->list, &slab_caches);
> +       s->refcount = -1;       /* Exempt from merging for now */
> +}
> +
> +struct kmem_cache *__init create_kmalloc_cache(const char *name, size_t size,
> +                               unsigned long flags)
> +{
> +       struct kmem_cache *s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> +
> +       if (!s)
> +               panic("Out of memory when creating slab %s\n", name);
> +
> +       create_boot_cache(s, name, size, flags);
> +       s->refcount = 1;
> +       return s;
> +}
> +
> +#endif /* !CONFIG_SLOB */
> +
> Index: linux/mm/slub.c
> ===================================================================
> --- linux.orig/mm/slub.c        2012-10-19 09:12:21.830023016 -0500
> +++ linux/mm/slub.c     2012-10-19 09:12:44.162404786 -0500
> @@ -3255,32 +3255,6 @@ static int __init setup_slub_nomerge(cha
>
>  __setup("slub_nomerge", setup_slub_nomerge);
>
> -static struct kmem_cache *__init create_kmalloc_cache(const char *name,
> -                                               int size, unsigned int flags)
> -{
> -       struct kmem_cache *s;
> -
> -       s = kmem_cache_zalloc(kmem_cache, GFP_NOWAIT);
> -
> -       s->name = name;
> -       s->size = s->object_size = size;
> -       s->align = ARCH_KMALLOC_MINALIGN;
> -
> -       /*
> -        * This function is called with IRQs disabled during early-boot on
> -        * single CPU so there's no need to take slab_mutex here.
> -        */
> -       if (kmem_cache_open(s, flags))
> -               goto panic;
> -
> -       list_add(&s->list, &slab_caches);
> -       return s;
> -
> -panic:
> -       panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
> -       return NULL;
> -}
> -
>  /*
>   * Conversion table for small slabs sizes / 8 to the index in the
>   * kmalloc array. This is necessary for slabs < 192 since we have non power
> @@ -3958,6 +3932,10 @@ int __kmem_cache_create(struct kmem_cach
>         if (err)
>                 return err;
>
> +       /* Mutex is not taken during early boot */
> +       if (slab_state <= UP)
> +               return 0;
> +
>         mutex_unlock(&slab_mutex);
>         err = sysfs_slab_add(s);
>         mutex_lock(&slab_mutex);
>

With above change, "if (slab_state < FULL) ~~" in sysfs_slab_add() is useless.
So, how about removing it?

Acked-by: Joonsoo Kim <js1304@gmail.com>

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  reply	other threads:[~2012-10-20 15:57 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20121019142254.724806786@linux.com>
2012-10-19 14:25 ` CK2 [01/15] slab: Simplify bootstrap Christoph Lameter
2012-10-22  7:57   ` Glauber Costa
2012-10-23 20:45     ` Christoph Lameter
2012-10-19 14:25 ` CK2 [02/15] create common functions for boot slab creation Christoph Lameter
2012-10-20 15:57   ` JoonSoo Kim [this message]
2012-10-19 14:32 ` CK2 [14/15] stat: Use size_t for sizes instead of unsigned Christoph Lameter
2012-10-22  8:42   ` Glauber Costa
2012-10-19 14:32 ` CK2 [05/15] Common alignment code Christoph Lameter
2012-10-19 14:32 ` CK2 [12/15] Common definition for the array of kmalloc caches Christoph Lameter
2012-10-19 14:42 ` CK2 [13/15] Common function to create the kmalloc array Christoph Lameter
2012-10-22  9:51   ` Glauber Costa
2012-10-19 14:42 ` CK2 [15/15] Common Kmalloc cache determination Christoph Lameter
2012-10-20 16:20   ` JoonSoo Kim
2012-10-23 20:40     ` Christoph Lameter
2012-10-19 14:42 ` CK2 [04/15] slab: Use the new create_boot_cache function to simplify bootstrap Christoph Lameter
2012-10-20 16:01   ` JoonSoo Kim
2012-10-22  8:09   ` Glauber Costa
2012-10-23 21:40     ` Christoph Lameter
2012-10-19 14:45 ` CK2 [08/15] slab: Use common kmalloc_index/kmalloc_size functions Christoph Lameter
2012-10-20 16:12   ` JoonSoo Kim
2012-10-23 20:39     ` Christoph Lameter
2012-10-24 17:47       ` JoonSoo Kim
2012-10-19 14:49 ` CK2 [09/15] slab: Common name for the per node structures Christoph Lameter
2012-10-20 16:14   ` JoonSoo Kim
2012-10-23 20:39     ` Christoph Lameter
2012-10-22  8:32   ` Glauber Costa
2012-10-19 14:51 ` CK2 [07/15] Common kmalloc slab index determination Christoph Lameter
2012-10-22  9:45   ` Glauber Costa
2012-10-23 20:48     ` Christoph Lameter
2012-10-19 14:51 ` CK2 [03/15] slub: Use a statically allocated kmem_cache boot structure for bootstrap Christoph Lameter
2012-10-19 14:51 ` CK2 [06/15] Move kmalloc related function defs Christoph Lameter
2012-10-22  8:11   ` Glauber Costa
2012-10-19 14:51 ` CK2 [10/15] slab: rename nodelists to node Christoph Lameter
2012-10-22  8:34   ` Glauber Costa
2012-10-19 14:58 ` CK2 [11/15] Common constants for kmalloc boundaries Christoph Lameter
     [not found] <20120928191715.368450474@linux.com>
2012-09-28 19:18 ` CK2 [02/15] create common functions for boot slab creation Christoph Lameter

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