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SLUB: extract dma_kmalloc_cache from get_cache. 

The rarely used dma functionality in get_slab() makes the function too
complex.  The compiler begins to spill variables from the working set onto the
stack.  The created function is only used in extremely rare cases so make sure
that the compiler does not decide on its own to merge it back into get_slab().

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Lameter 2007-07-17 04:03:24 -07:00 committed by Linus Torvalds
parent 0c71001320
commit 2e443fd003
1 changed files with 36 additions and 30 deletions
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66
mm/slub.c
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@ -2272,6 +2272,40 @@ static struct kmem_cache *create_kmalloc_cache(struct kmem_cache *s,
panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
}
#ifdef CONFIG_ZONE_DMA
static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
{
struct kmem_cache *s;
struct kmem_cache *x;
char *text;
size_t realsize;
s = kmalloc_caches_dma[index];
if (s)
return s;
/* Dynamically create dma cache */
x = kmalloc(kmem_size, flags & ~SLUB_DMA);
if (!x)
panic("Unable to allocate memory for dma cache\n");
if (index <= KMALLOC_SHIFT_HIGH)
realsize = 1 << index;
else {
if (index == 1)
realsize = 96;
else
realsize = 192;
}
text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
(unsigned int)realsize);
s = create_kmalloc_cache(x, text, realsize, flags);
kmalloc_caches_dma[index] = s;
return s;
}
#endif
static struct kmem_cache *get_slab(size_t size, gfp_t flags)
{
int index = kmalloc_index(size);
@ -2284,36 +2318,8 @@ static struct kmem_cache *get_slab(size_t size, gfp_t flags)
return NULL;
#ifdef CONFIG_ZONE_DMA
if ((flags & SLUB_DMA)) {
struct kmem_cache *s;
struct kmem_cache *x;
char *text;
size_t realsize;
s = kmalloc_caches_dma[index];
if (s)
return s;
/* Dynamically create dma cache */
x = kmalloc(kmem_size, flags & ~SLUB_DMA);
if (!x)
panic("Unable to allocate memory for dma cache\n");
if (index <= KMALLOC_SHIFT_HIGH)
realsize = 1 << index;
else {
if (index == 1)
realsize = 96;
else
realsize = 192;
}
text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
(unsigned int)realsize);
s = create_kmalloc_cache(x, text, realsize, flags);
kmalloc_caches_dma[index] = s;
return s;
}
if ((flags & SLUB_DMA))
return dma_kmalloc_cache(index, flags);
#endif
return &kmalloc_caches[index];
}