SLUB: extract dma_kmalloc_cache from get_cache. (2e443fd0) · Commits · 戴 / test

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>

mm/slub.c

+36 −30

Original line number	Diff line number	Diff line
		@@ -2272,19 +2272,9 @@ panic:
		panic("Creation of kmalloc slab %s size=%d failed.\n", name, size);
		}

		static struct kmem_cache *get_slab(size_t size, gfp_t flags)
		{
		int index = kmalloc_index(size);

		if (!index)
		return ZERO_SIZE_PTR;

		/* Allocation too large? */
		if (index < 0)
		return NULL;

		#ifdef CONFIG_ZONE_DMA
		if ((flags & SLUB_DMA)) {
		static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags)
		{
		struct kmem_cache *s;
		struct kmem_cache *x;
		char *text;
		@@ -2314,6 +2304,22 @@ static struct kmem_cache *get_slab(size_t size, gfp_t 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);

		if (!index)
		return ZERO_SIZE_PTR;

		/* Allocation too large? */
		if (index < 0)
		return NULL;

		#ifdef CONFIG_ZONE_DMA
		if ((flags & SLUB_DMA))
		return dma_kmalloc_cache(index, flags);
		#endif
		return &kmalloc_caches[index];
		}

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